Cardiac Catheterization in Congenital Heart Disease: Pediatric and Adult - Part 6 ppt

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CHAPTER 18 Coarctation dilation
464
completely. The sheath is withdrawn and pressure
applied over the vessel manually. As soon as all the
sheaths are out, the drapes over the patient are removed
completely so that the lower abdomen and upper thigh
areas adjacent to the entire inguinal area are visible. While
holding pressure over the arterial puncture site with the
ﬁngers of one hand, a pulse distal to the puncture site
(dorsalis pedis or posterior tibial) is palpated with the
ﬁngers of the other hand. The amount of pressure applied
over the arterial puncture site is varied or “titrated” so
that just enough pressure is applied to prevent bleeding
(or a subcutaneous hematoma formation) while at the
same time allowing the palpation of a peripheral pulse
continually. In larger or heavier patients, it is better
to apply pressure over the arterial site with a ﬁrm “roll” of
“4 × 4s”, since the exact site of arterial puncture deep
within thick subcutaneous tissues does not correspond at
all to the site of the skin puncture and subsequent pres-
sure. The pressure from the “roll” of bandage covers a
wider area deep within the tissues and is more likely to
control deep bleeding from the artery. The same tech-
nique for monitoring the peripheral pulse is used while
pressure is applied with the “roll” of bandage.
In addition to the care of the local puncture sites, these
patients are monitored systemically very closely in a
recovery area for at least six hours. During this observa-
tion period, they should have a secure intravenous line
and receive a high maintenance infusion of 1/4 normal
saline or Ringer’s lactate. The intravenous ﬂuids are con-

tinued for twelve hours. A patient following dilation of a
coarctation of the aorta usually has diuresed during the
procedure from both the contrast agents used and from
the increased renal blood ﬂow as a consequence of the
relief of the coarctation. Often these patients start out “dry”
from being NPO for a prolonged period of time before the
procedure begins. The combination of these factors results
in a very signiﬁcant volume depletion, which, in turn,
aggravates vagal or other vascular responses caused by
the changes in the distribution of arterial blood ﬂow.
Surprisingly, post-dilation patients rarely suffer from
the “post-coarctectomy” syndrome that is seen commonly
following surgery. Dilation patients rarely have any
aggravation of their upper extremity blood pressure,
although the systemic pressures may not drop to normal
immediately
13
. Post-dilation patients essentially never have
abdominal discomfort and usually resume oral intake
within 6–12 hours after dilation. There have been reports
of serious post-procedure complications following the
dilation of coarctations, so no matter how smoothly the
procedure went, these patients are observed overnight.
Although they may exhibit pain during the actual balloon
inﬂation in the coarctation site, once the balloon is deﬂated,
the pain subsides. Any persistent or recurrent pain should
be taken seriously and investigated thoroughly.
Dilation of coarctation neonates and
young infants
Coarctation of the aorta in the neonatal patient presents

some unique features. These infants frequently present to
the cardiologist catastrophically ill with heart failure, in
acidosis and in shock. They frequently have additional
defects, some of which complicate the catheter manage-
ment and some of which actually help the catheter man-
agement. The identiﬁcation of any additional defects is
made from the clinical examination and the echocardio-
gram. The echo cannot consistently provide the details
about the coarctation size, anatomy and severity, and fre-
quently underestimates the size of the adjacent aortic seg-
ments. Decisions about therapeutic intervention for the
neonatal coarctation of the aorta should not be made
entirely on the basis of the echo.
A vigorous, but brief attempt is made at stabilizing
infants who are less than three to four weeks old with vent-
ilation, inotropics, volume support and prostaglandin.
Stabilization attempts are continued only as long as the
infant improves. If there is going to be any improvement in
the clinical condition, it is noticeable within one to two
hours. With, or without, the stabilization after that dura-
tion of time, the infant is taken to the catheterization lab-
oratory. If the infant is not responding noticeably to the
resuscitative efforts, more time only allows further deteri-
oration. If the infant is responding, the improvement will
continue on the way to, and in, the catheterization labor-
atory. The exact procedure performed depends upon the
presence or absence of associated lesions and, when pres-
ent, which associated lesions are present.
Besides their general hemodynamic instability, the very
small femoral arteries with the associated very weak or

absent femoral pulses represent the greatest challenge for
balloon dilation of coarctation of the aorta in the very
small infant. In each individual case, the most expeditious
technique possible is utilized to approach and treat the
coarctation. Once the coarctation area has been reached
with a catheter, the gradient is measured, the selective
aortogram(s) performed and accurate measurements of
the coarctation and adjacent vessels are made in order to
choose the proper balloon.
When the infant responds to the administration of
prostaglandins with opening of the ductus arteriosus, the
stabilization of the infant is usually rapid and very effect-
ive. The presence of the patent ductus indirectly facili-
tates access to the coarctation by improving perfusion
to the lower extremities signiﬁcantly, and increases the
amplitude of the femoral pulses, which facilitates percuta-
neous arterial access. The presence of a patent ductus,
however, compromises the results of balloon dilation of
a neonatal coarctation. Without the patent ductus, the
CHAPTER 18 Coarctation dilation
465
balloon is constrained within the aorta and the “path of
least resistance” is to crush the abnormal ridge of tissue
within the aortic lumen. A wide open ductus arteriosus,
on the other hand, allows the dilation balloon to move
away from the coarctation “ridge” into the “ampulla” of
the ductus rather than crushing or compressing the ridge.
In addition, when the ductus does constrict during its nor-
mal closure, it probably also constricts some of the adjac-
ent aorta, recreating the coarctation.

Most of the newborns and small infants with coarcta-
tion do have at least a potential interatrial communication.
In all of these infants, venous access is obtained and an
angiographic catheter is introduced into at least the left
ventricle from the venous approach. At the same time, in a
small sick infant, no prolonged effort should be made at
advancing this catheter from the left ventricle into the
aorta, as is utilized in coarctation dilation in the older
patient. The chambers and vessels are very small and the
tissues “softer” and prone to puncture. The catheter in the
left ventricle provides continual systemic pressure mon-
itoring before, during and immediately after the dilation
procedure. The pressure in the left ventricle reﬂects the
severity of the coarctation unless there is associated aortic
stenosis or the infant is in terrible heart failure. A left ven-
tricular angiocardiogram is performed which provides
some, and possibly, very good information about the
coarctation and the overall anatomy.
Infants who do not respond to prostaglandins and who
have no associated lesions, and those who have associated
aortic stenosis, are the most difﬁcult for coarctation dilation.
The echocardiogram should diagnose associated aortic
stenosis and give an estimate of its severity, although
either one of the two lesions can mask the signiﬁcance of
the other. The prograde left ventricular catheter is useful
in these patients for monitoring pressures and for the
administration of ﬂuid and medication, and is possibly
helpful in determining the relative severity of com-
bined lesions.
Percutaneous entry into the artery is accomplished with

meticulous attention to detail, a very delicate single wall
vessel puncture technique, and patience (as described in
Chapter 4). The area around the expected arterial punc-
ture site is inﬁltrated with local anesthesia, being as care-
ful as possible not to puncture the artery with the needle
during the inﬁltration. If the artery is punctured inadvert-
ently, pressure is held over the site for at least 2–4 minutes
before beginning the purposeful puncture of the artery.
Special 21-gauge percutaneous needles and extra-ﬂoppy
tipped 0.018″ or 0.014″ wires are essential for the percuta-
neous entry into the artery in these patients. Once the
artery has been entered with the guide wire, the area sur-
rounding the puncture site is re-inﬁltrated liberally with
local anesthesia. A 3- or 4-French “ﬁne tipped” sheath/dila-
tor is introduced into the artery. The preliminary diagnostic
information about the coarctation is obtained with the re-
trograde catheter. If the infant is still very unstable, an end
and side hole multipurpose catheter is used. This type of
catheter allows pressure measurements and quality aor-
togram(s), and at the same time can be used to position the
guide wire for the dilation without the necessity of even
one catheter exchange. The second catheter previously
positioned in the left ventricle helps to conﬁrm the pres-
ence of associated aortic stenosis. However, with poor left
ventricular function and an associated coarctation of the
aorta, even very severe aortic stenosis can be masked.
Once the coarctation has been identiﬁed as the only
signiﬁcant lesion, it is measured accurately and the dilation
of the coarctation is carried out as expediently as possible
using the single-catheter, retrograde technique. It is

preferable to stabilize the distal end of the guide wire in
one of the subclavian arteries, although an excessively
long time or effort should not be taken to achieve this loca-
tion. The balloon for the coarctation dilation is chosen to
equal the size of the smallest segment of the aorta adjacent
to the coarctation. Once the dilation has been completed
and the balloon removed over the wire, the end-hole
catheter is re-advanced over the wire and very gently past
the coarctation to the aorta proximal to the coarctation.
The wire is removed and pressures are recorded simulta-
neously through the catheter from the ascending aorta
and through the side arm of the sheath from the femoral
artery. A repeat aortogram is recorded, injecting through
the end-hole catheter proximal to the coarctation site.
The catheter should not be withdrawn across the coarc-
tation site until all post-dilation studies or any re-dilation
has been accomplished. If the dilation was unsatisfactory
and a re-dilation is necessary, the wire is replaced through
the catheter which is already across and well beyond the
lesion in order that no catheter manipulation back across
the freshly dilated area is necessary. When the catheter
has been withdrawn across the area, it should not be
manipulated back across the area
3
.
Co-existent critical aortic stenosis and
coarctation in infants
When there is signiﬁcant aortic stenosis in association
with the neonatal coarctation, it is preferable to address
the aortic stenosis ﬁrst. In the presence of the combined

lesions, perfusion of the coronary and cerebral circula-
tions is dependent, at least partially, on the increased
afterload in the ascending aortic pressure provided by the
coarctation. Removing this afterload before opening the
aortic valve could compromise the coronary and cerebral
circulations even further. In addition, if the coarctation is
dilated ﬁrst, all of the manipulations (sometimes extens-
ive) required for crossing the aortic valve, and the aortic
valve dilation, will have to be through the freshly dilated
CHAPTER 18 Coarctation dilation
466
coarctation site with the potential for traumatizing the
already damaged aortic intima in the coarctation site even
further.
With combined aortic stenosis and coarctation, the
diameters of the aortic valve annulus and the coarctation
with the appropriate adjacent aortic diameters are meas-
ured from a left ventricular angiocardiogram or an aortic
root injection before an attempt is made to pass a catheter
across the stenotic valve. A left ventricular angiocardio-
gram is obtained with injection through a prograde left
ventricular catheter, while the aortic root injection is
obtained with the retrograde multipurpose or angio-
graphic catheter that has been manipulated past the coarc-
tation and around the arch to the aortic root. Once the
valve and coarctation measurements are obtained, the
appropriate dilation balloon for the aortic valve dilation is
prepared using the “minimal prep” technique but with
a prolonged attempt at removing all air. No attempt is
made to cross the aortic valve until the balloon for the dila-

tion is prepared and “poised” for introduction. These
infants are often so precarious that even a tiny 4-French
catheter crossing the stenotic oriﬁce is enough to cause a
rapid decompensation in their hemodynamics.
To cross these valves, a 0.018″ or 0.014″, very ﬂoppy
tipped, exchange length, torque-controlled, coronary
artery, guide wire is advanced through a multipurpose or
selective right coronary catheter which is already posi-
tioned in the aortic root. The wire is advanced out of the
catheter and multiple, rapidly repeated, short probes are made
toward the aortic valve area with the very soft wire tip.
Because even a very soft tipped wire exiting the tip of the
catheter can be very stiff for the ﬁrst few millimeters out of
the tip, the tip of the catheter is kept a centimeter away
from the valve annulus during the probes with the tip of
the wire. The tip of the wire is redirected within the aortic
root by simultaneously rotating the catheter (to change
the anterior to posterior direction) and moving the
catheter to and fro (to change the right to left side angle).
Unless another wire or catheter is already passing
through the valve, the exact location of the oriﬁce really is
not known. The more “probes” that are made with the
wire along with multiple changes in the angle of the wire,
the more likely is the chance of the wire passing through
the oriﬁce of the “invisible” valve.
If the wire does not cross the valve after trying for
several minutes using the original multipurpose catheter,
the multipurpose catheter is replaced with a preformed,
either right or left coronary catheter and the “probing” at
the valve repeated with similar changes in direction of the

catheter tip. The tighter, preformed curves at the tips of
coronary catheters allow a greater ability to change the
angle of approach toward the small valve oriﬁce.
Once the wire crosses the valve, it is advanced as far as
possible into the ventricle, hopefully even looping the soft
tip within the left ventricle apex. With the wire passed as
far as possible into the ventricle, the catheter is advanced
over the wire into the ventricle. If the infant’s hemody-
namics do not remain stable with the catheter across the
valve, the wire is ﬁxed in the ventricle and the catheter is
immediately removed and replaced rapidly over the wire
with the previously prepared balloon dilation catheter.
The dilation of the valve is carried out with as rapid an
inﬂation and deﬂation as possible and while recording
angiographically or on “stored ﬂuoroscopy”. After the
inﬂation/deﬂation, the balloon is immediately with-
drawn out of the valve over the wire into at least the
ascending aorta.
If the infant remains stable with the end-hole catheter
passed through the valve, the wire is removed. A “pig-
tail” is formed on the tip of the long ﬂoppy tipped, stiffer,
exchange guide wire and a 180° curve is formed on the
transition zone between the long ﬂoppy tip and the stiff
shaft of the wire. This individually formed wire is re-
advanced through the catheter into the left ventricle. The
preformed “pig-tail” on the wire keeps the wire from
digging into the myocardium as it is manipulated in the
ventricle. The 180° curve at the transition area of the wire
directs the tip of the wire back toward the left ventricular
outﬂow tract and allows the stiff portion of the shaft of the

wire to be positioned further across the valve. With the
wire maintained in position, the catheter is removed and
replaced with the already prepared balloon catheter. The
balloon is positioned across the valve and the inﬂation
performed while recording the inﬂation angiographically
or on “stored ﬂuoroscopy”. The inﬂation/deﬂation is per-
formed as rapidly as possible. During the inﬂation the left
ventricular pressure increases and the infant develops
bradycardia. As soon as the deﬂation of the balloon is
complete, the balloon is withdrawn over the wire and out
of the aortic annulus. The infant’s heart rate should return
and the left ventricular pressure will drop to normal levels.
The return of a good heart rate and a good, but lower,
left ventricular pressure are immediate indications of the
success of the dilation. Ideally, there will be a lower left
ventricular pressure, but in the presence of the associated
coarctation, the gradient may be “moved downstream” to
the coarctation site with little lowering of the left ventricu-
lar pressure. The radiographic recording of the inﬂation/
deﬂation is reviewed. If a “waist” appeared on the balloon
and then disappeared during the inﬂation, some true
dilation of the valve oriﬁce is assumed. The balloon is
withdrawn back to the area of the coarctation. If the dia-
meter of this balloon is smaller, or, at least, no more than a
millimeter larger, than the measurement of the smallest
diameter of the aorta adjacent to the coarctation, the
coarctation site is dilated with the same balloon. If the bal-
loon is two or more millimeters larger than the adjacent
aorta in the area of the coarctation, the balloon is replaced
CHAPTER 18 Coarctation dilation

467
with an appropriate diameter balloon and the coarcta-
tion dilated.
After both the aortic valve and the coarctation have
been dilated the balloon is removed and replaced with a
catheter to re-evaluate the hemodynamics. If there is a left
ventricular catheter in place, the “net” results of the com-
bined dilation are determined by measuring the left vent-
ricular and femoral artery pressures simultaneously using
the side arm of the sheath for the femoral artery. If the net
left ventricular to femoral artery gradient is low, it is
assumed that both procedures were successful and the
procedure can be concluded. A left ventricular angiocar-
diogram through the prograde catheter provides visual-
ization of both the aortic valve and the coarctation area.
An end-hole catheter is passed over the wire to the left
ventricle and the retrograde wire removed. Pressures are
recorded on withdrawal of the retrograde catheter from
the left ventricle, to the aorta and across the coarctation
site to quantitate the residual gradients at each area.
If the net gradient is still signiﬁcant, the culprit lesion(s)
is/are identiﬁed from the pressures and angiograms. If
there is no prograde catheter in the left ventricle, the
results of the dilations must still be determined. A Multi-
Track™ catheter provides the most “secure” way of iden-
tifying the major residual problem without having to
remove the wire from the left ventricle. Pressures are
recorded and angiograms are performed through the
Multi-Track™ catheter anywhere along the course from
the left ventricle to the descending aorta and all without

having to remove the wire, which can be maintained posi-
tioned in the left ventricle. A small, stiff wire is placed in
the true catheter lumen of the Multi-Track™ catheter to
stiffen and support the catheter shaft as Multi-Track™ is
being advanced over the exchange wire. Once the Multi-
Track™ catheter is in the left ventricle, the wire within the
true lumen is removed. Angiograms are performed where
appropriate and pressures are recorded as the Multi-
Track™ is withdrawn over the exchange wire. When a
signiﬁcant area of residual obstruction is identiﬁed, the
decision is made whether this should or can be treated
from the pressures, the review of the balloon dilations and
the current angiograms performed through the Multi-
Track™ catheter. If a lesion is to be re-dilated, the Multi-
Track™ is removed over the wire and the appropriate
balloon dilation catheter reintroduced to the culprit lesion.
If a Multi-Track™ catheter is not available or cannot be
used with the particular system, then an end-hole, multi-
purpose catheter is advanced over the wire to the left
ventricle and the exchange wire removed. Pressures
are recorded and sequential angiograms are obtained
through this catheter as it is withdrawn from the left vent-
ricle to the ascending aorta and from the ascending aorta
to the descending aorta. This, of course, removes the pre-
viously secure wire access back into the ventricle! If the
signiﬁcant or predominant gradient is at the aortic valve,
the catheter withdrawal is stopped in the aortic root and a
decision is made as to whether further catheter therapy is
possible. If the aortic valve is to be re-dilated, the soft
ﬂoppy tipped wire is reintroduced through the catheter

and manipulated across the aortic valve into the left ven-
tricle. The dilation procedure is repeated with a more
appropriate diameter balloon.
If there is a signiﬁcant net left ventricle to femoral artery
gradient, but little or no gradient at the aortic valve, the
coarctation is still the culprit. The previous coarcta-
tion dilation is reviewed. If a larger balloon can be used,
the wire is reinserted into the catheter and positioned
in the aortic root before the catheter is withdrawn across
the coarctation. The end-hole catheter is removed over the
wire, the appropriate diameter balloon is passed over
the wire and the coarctation re-dilated. Reassessment of
the result depends upon which catheters are available,
as described above.
Whenever an infant is found to have coarctation of the
aorta with aortic stenosis, associated mitral stenosis of
some type and degree should be suspected. The Shone’s
complex of multiple left heart obstructive lesions includes
various types of mitral valve stenosis along with the
coarctation and aortic stenosis, and frequently results
in an even sicker infant. Any one, or all, of the levels of
obstructive lesions can be severe and require intervention,
however usually the coarctation and aortic lesions are the
most pressing and are the only ones that can be addressed
reasonably in the newborn period. Congenital mitral
stenosis can be treated by balloon dilation in the slightly
older child, and is addressed separately in Chapter 20.
The most favorable associated lesions in an infant with
coarctation that need dilation are a ventricular septal
defect (VSD) and transposition of the great arteries. A

VSD provides access to the aorta from the right heart and
in turn from the venous access. Although access to the
coarctation through the VSD is anticipated, these infants
should have an indwelling arterial line for systemic pres-
sure monitoring. In these patients, a curved tipped, end-
hole or multipurpose catheter introduced through a short
sheath from a percutaneous venous introduction is used
for the “right heart” procedure. In infants, when manipu-
lating a venous catheter from the right ventricle toward
the outﬂow tract, as the catheter is torqued clockwise,
it frequently and, even preferentially, passes dorsally
through the ventricular defect and, from there, into the
ascending aorta. Otherwise, with purposeful manipula-
tion of the catheter dorsally and cephalad from the right
ventricle, entering the aorta almost always is accom-
plished in infants with a signiﬁcant VSD. From there,
approaching the coarctation around the arch is a straight-
forward procedure with a wire and curved tip catheter.
A selective aortogram is performed and the lesion and
CHAPTER 18 Coarctation dilation
468
adjacent vessels measured accurately. The coarctation
is crossed with a prograde end-hole catheter and the
catheter is exchanged for the exchange length, stiff, guide
wire. The balloon is introduced from the vein and
advanced through the right ventricle, through the VSD
and to the coarctation. The dilation is accomplished all
prograde from the venous entry site without the need
for even a 3-French sheath in a femoral artery. The post-
procedure measurements are carried out with an end-hole

catheter replacing the balloon catheter in the aorta before
the “prograde” guide wire is removed.
The same ability to perform a dilation of a coarctation
from a venous access holds true for infants with coarcta-
tion of the aorta in association with transposition of the
great arteries (with or without a ventricular septal defect
or aortic or pulmonary override). This is a particularly
common association in patients with the so-called Taussig–
Bing complex of transposition of the great arteries, ven-
tricular septal defect and pulmonary artery override. A
standard end-hole or a balloon “wedge” catheter passes
easily from the right ventricle and out into the aorta. With
minimal manipulation the catheter is maneuvered into
the descending aorta to the coarctation. The diagnosis and
dilation are performed similarly to that in the infant with
an associated VSD.
Intravascular stents in coarctation of the aorta
The use of intravascular stents for the treatment of coarc-
tation of the aorta has become the primary approach for
coarctation in the larger adolescent and adult. The use and
advantages of intravascular stents in both native and
re/residual coarctation are covered in detail in Chapter
25. Their use in conjunction with dilation of coarctation of
the aorta has changed the approach to these lesions dra-
matically. Intravascular stents not only support the ves-
sels at the maximal dilated diameter of the balloon, but
also, in doing so, eliminate the need for any over-dilation
of the vessel.
However, the basic rules for the implant of intravascu-
lar stents in pediatric and congenital lesions apply even

more stringently to their use in coarctations. In particular,
no stent should be implanted in the aorta if it cannot be
dilated up to the ultimate adult diameter of the aorta in that
particular patient. This “rule” so far has precluded the rea-
sonable and/or sensible use of stents in coarctation of the
aorta in infants and small children. The implant of a stent
that cannot be dilated to the diameter of the adult aorta,
creates a new, very ﬁxed diameter coarctation as the
patient grows. A coarctation with a stent in place, which is
too small for the aorta and which cannot be dilated fur-
ther, must be managed surgically. There is a much higher
risk for surgery on a coarctation with a stent in place than
for the surgical repair of native coarctation, even in an
infant. The narrow segment of aorta that contains the
stent, at the very least, must be “ﬁlleted” open and then
patched, if not totally resected or bypassed with a pros-
thetic graft. At the same time, this same patient who
requires such extensive surgery on the aorta, no longer
has the extensive collaterals to protect the spinal cord and
the lower half of his body. Hopefully, the further develop-
ment of “open ring” stents or some type of resorbable
stent, will eventually make it possible to use stents in the
initial treatment of coarctation in infants and children.
In the interim, balloon dilation of coarctation is very
effective in infants and children. Even if the obstruction of
the coarctation is not eliminated totally with an initial
dilation, or even with several balloon dilations, if the aorta
is not over-dilated and torn or ruptured, a successful bal-
loon dilation with a stent implant can be accomplished
when the patient reaches adolescence or adulthood. For

the infant and child, a “conservative” dilation of both
native and re/residual coarctation should be the primary
approach to these lesions.
Complications speciﬁc to coarctation
dilation
The majority of the early dilations reported in the
Valvuloplasty and Angioplasty of Congenital Anomalies
(VACA) registry were for re-coarctation of the aorta and,
as a consequence, the majority of the acute complications
were in these re-coarctation dilations. In the VACA series
of re-coarctation dilations there were ﬁve deaths (two
vagal, one aortic rupture, one CNS death and one death
due to shock)
1
.
A better understanding of the effect of the post-dilation
vasodilation and the exaggerated physiologic vasovagal
response to the pressure drop associated with dilations
has helped to eliminate the extreme vasovagal response
to the procedure. The patients are maintained on a high
maintenance volume of intravenous ﬂuids during the
dilation and this ﬂuid infusion is maintained for six to
twelve hours after the dilation. The intravenous access
is left in place until after the patient is ambulated. With
these precautions, the vasovagal type reactions have
been eliminated.
Signiﬁcant central nervous system (CNS) injuries and at
least one death attributed to CNS injury have been
reported following dilation of coarctation of the aorta. The
exact etiology of all of the CNS injuries has never been

determined unequivocally. Fortunately, with more atten-
tion to the position of the distal end of the guide wire for
support of the dilation balloon and extremely stringent
precautions concerning emboli from the materials and/or
the procedure, the central nervous system complica-
tions essentially have been eliminated. It is critical that the
CHAPTER 18 Coarctation dilation
469
distal end of the support wire is not positioned in a carotid
or vertebral artery or possibly even in the ascending aorta.
Catheters passed over wires are maintained on a contin-
ual ﬂush in order to eliminate any accumulation of blood
and clot around the wire within the catheter or at the
wire–catheter interface. Flushing over the wire is accom-
plished by introducing the wire through a wire back-
bleed valve with a ﬂush side port, which is attached to the
hub of the catheter. The side port of the wire back-bleed
valve is maintained on continual ﬂush from the pres-
sure/ﬂush system. In spite of the theoretical potential for
an aortic tear, patients undergoing coarctation dilation are
heparinized fully with the hope of eliminating clot forma-
tion on the wires or catheters.
Although possible, acute, through and through tears in
the aortic wall from the dilation of coarctations have been
exceedingly rare. One report early in the history of dila-
tion of coarctation of the aorta was in a patient with
re-coarctation of the aorta who had remarkably little or
no reaction or scar formation from the prior surgery and
apparently little or no reaction to the acute local injury.
The patient had a through and through tear in the aortic

wall and eventually succumbed to the lesion. Possibly,
aortic tears cannot be avoided unequivocally, however it
appears likely that aortic tears can be prevented by less
aggressive initial dilation of aortic coarctations and not
over-dilating any segment of the aorta adjacent to the area
of the coarctation by measuring that area of the aorta and
using that measured diameter to determine the diameter
of the balloon for the dilation. Dilation of a typical “native”
coarctation presumably tears a “membrane” that lies
across the lumen of the aorta and does not extend the tear
signiﬁcantly into the wall of the aorta. Dilation of an
equally tight “re or residual” coarctation probably involves
dilation of the actual wall of the aorta which has con-
stricted down in the area of the previous therapy and, as a
consequence, these should be dilated more conservatively.
Most patients exhibit pain acutely during the process of
inﬂating a balloon in the aorta, however the pain subsides
when the balloon is deﬂated. If a patient has persistent pain
after acute dilation of the coarctation, the area of the coarc-
tation should be investigated carefully with selective
aortography or intravascular ultrasound in the area of the
dilation. Even without identifying a tear, the patient
should be observed in the catheterization laboratory until
the pain subsides or for one or more hours if the pain
persists. If a through and through tear with progressive
extravasation is detected, the balloon is reinﬂated at a low
pressure in the area of the tear. The inﬂation is just enough
to “tamponade” the vessel and allow the patient to be
taken to the operating room for a repair. Such a surgical
aortic repair certainly will require relatively prolonged

cross clamping of the aorta and in turn, may require
femoral vein to femoral artery bypass.
There has been one report of paraplegia following a
balloon dilation of a re/residual coarctation of the aorta in
a small infant with associated complex congenital heart
disease
14
. The prior surgery on the aorta had involved an
uncomplicated end-to-end anastomosis. There was no pro-
longed ischemia, no evidence of aortic tear nor any evid-
ence for embolic phenomena to explain the paraplegia.
In the early reported series of coarctation dilation, there
was an 8.5% incidence of signiﬁcant enough injury to the
arterial introductory site to require intervention or have
permanent sequelae at the entrance site into the vessel. In
those early years of balloon dilation, the balloon dilation
catheters were very large and the balloons themselves
were large and grotesque by today’s standards. All of the
balloons greater than 6 mm in diameter were on 9-French
catheter shafts, the balloons were relatively thick walled
and they did not fold well around the catheter so that the
balloon “mass” had a very large proﬁle. In order to be
introduced through a sheath these balloons required an
11- or 12-French sheath! As a consequence to “reduce the
size” of the entry hole into the vessel most of these early
balloons were introduced into the vessels directly over a
wire without a sheath in the vessel. This in fact probably
did not reduce the diameter of the “hole” in the vessel
wall and certainly contributed to signiﬁcantly more local
trauma to the vessel walls. Considering the balloon

catheters used at that time, the incidence of arterial injury
actually was remarkably low!
Many reﬁnements in the balloons with marked reduc-
tion in the size of the catheter shafts and decrease in the
balloon proﬁles have not only allowed a smaller “hole”
for introduction into the vessel, but have also allowed
dilation balloons routinely to be introduced through
indwelling sheaths. With the combination of smaller
balloon proﬁles, routine use of indwelling sheaths, very
meticulous care of the introductory sites into the arteries,
liberal, repeated use of local anesthesia, heparinization
(perhaps?), and personal attention to the site during
hemostasis after the balloon/sheath is removed, local
vessel injury is now very rare.
When an acute arterial injury does occur, it is treated
aggressively at the time of the catheterization. With an
absent pulse, the patient is continued on heparin therapy
for one or two hours or until the pulse returns. If there is
no return of a pulse within 1–2 hours the patient is either
begun on thrombolytic therapy with continued heparin
or is taken back to the catheterization laboratory for a
mechanical recanalization of the vessel, as described in
Chapter 34 on purposeful perforations.
With only a 20-year history of balloon dilation of coarcta-
tion of the aorta, any long-term adverse sequelae from
the procedure are as yet unknown. The “longer-term”
adverse sequelae that have occurred so far, seem to occur
more with the dilation of “native” coarctation of the aorta
CHAPTER 18 Coarctation dilation
470

where the aorta is not “protected” by a surrounding area
of scar tissue, as is found around the re-coarctations. The
most bothersome ﬁnding after coarctation dilation is the
creation of an “aneurysm” at the site of the coarctation
dilation. The incidence of these aneurysms has varied
markedly in different series, but in general they are rare.
The “aneurysms” are usually a small out-pouching in
the aortic wall in the area of the balloon dilation. This
out-pouching is usually apparent immediately after the
dilation. In most cases the out-pouching does not enlarge
and in fact seems to remodel into the aortic wall along with
the overall remodeling of the aorta. The out-pouching of
the aorta is considered an aneurysm when the area
“remodels” into a persistent, discrete out-pouching. There
are no reported long-term adverse consequences of the
aneurysms, however, in at least one series, several of
the patients with an aneurysm did undergo surgery for
it. The indication for the surgery was not because of
any clinical problem due to the aneurysm, but because of
the fear of what might happen to the aneurysm over time.
The pathology of those aneurysms that were operated
upon showed tears through the intima and media of the
vessel wall. Some aneurysms have been followed for
as long as 18 years with no increase in their size and
no sequelae.
Aneurysms of the aorta following surgical repair are not
uncommon. These aneurysms are more frequent when
there is a persistent narrowing of the aorta proximal to the
coarctation repair site or when the surgical repair was
carried out with a patch angioplasty. These post-surgical

aneurysms are large saccular dilations of the entire area
of the coarctation/aorta distal to the more proximal
“obstruction”. Most of these aneurysms continue to
grow with time and most have been referred for surgical
revision.
The total incidence of aneurysms following coarcta-
tion dilation initially was small and actually seems to be
decreasing and, possibly, not occurring at all in more
recent series. In the earlier days of coarctation dilation, the
measurements of the coarctation and the adjacent vessels
were less accurate, and less attention was paid to the
narrow adjacent structures. Often, marked over-dilation
of these areas was carried out with balloons signiﬁcantly
larger in diameter than the adjacent vessel, either because
of the inaccuracies in measurement or purposefully in an
attempt to achieve a more lasting result. Perhaps the more
conservative dilations done with the knowledge that the
aorta can be dilated further later or can be held open
with an intravascular stent without the need for any over-
dilation will totally eliminate the aneurysms associated
with coarctation dilations. When a discrete aneurysm
does occur, it should be followed closely, probably at
least every one or two years with repeated CT, MRI, or
angiographic imaging.
A discrete aneurysm can be excluded by a stent graft
(large covered stent) or covered with a standard intra-
vascular stent to support the aortic wall in the area and
then to have coils packed into the aneurysm behind the
intravascular stent.
Conclusion

Balloon dilation is an accepted standard treatment for
both native and re/residual coarctation of the aorta in
patients of all ages in many major cardiovascular centers
dealing with congenital heart disease. The safety of the
acute procedure now appears to be very good, perhaps
because of a better understanding of the lesions and a
more conservative approach to the dilation procedure.
A patient who undergoes a conservative dilation of coarc-
tation of the aorta and who has a less than optimal result,
but at the same time has no complications, can always have
the dilation of the coarctation repeated with, or without,
the implant of an intravascular stent to “complete” the
procedure.
The success of dilation of coarctation of the aorta over
the years and the reduction in the complications and
the difﬁculties with repeat surgery on patients with
re/residual coarctation have made dilation of native and
re/residual coarctation the procedure of choice in most
centers. Most centers stipulate that all patients who have
dilation of any type of coarctation of the aorta should be
followed indeﬁnitely. In patients who are, or are at least
near to, full-grown many centers now regularly perform
primary intravascular stent implants along with dilation
of coarctation of the aorta. The use of stents in coarctation
of the aorta is covered in detail in Chapter 25.
References
1. Hellenbrand WE et al. Balloon angioplasty for aortic re-
coarctation: Results of the Valvuloplasty and Angioplasty
of Congenital Anomalies Registry. Am J Cardiol 1990; 65:
793–797.

2. Tynan M et al. Balloon angioplasty for the treatment of native
coarctation: Results of the Valvuloplasty and Angioplasty
of Congenital Anomalies Registry. Am J Cardiol 1990; 65:
790–792.
3. Finley JP et al. Balloon catheter dilatation of coarctation of the
aorta in young infants. Br Heart J 1983; 50: 411–415.
4. Lock JE et al. Balloon dilation angioplasty of aortic coarcta-
tions in infants and children. Circulation 1983; 68(1): 109–116.
5. Kappetein AP et al. More than thirty-ﬁve years of coarctation
repair. An unexpected high relapse rate. J Thorac Cardiovasc
Surg 1994; 107(1): 87–95.
6. Wada T et al. Prevention and detection of spinal cord injury
during thoracic and thoracoabdominal aortic repairs. Ann
Thorac Surg 2001; 72(1): 80–84; discussion 85.
CHAPTER 18 Coarctation dilation
471
7. Kalita J et al. Evoked potential changes in ischaemic myelo-
pathy. Electromyogr Clin Neurophysiol 2003; 43(4): 211–215.
8. John CN et al. Report of four cases of aneurysm complicating
patch aortoplasty for repair of coarctation of the aorta. Aust
NZ J Surg 1989; 59(9): 748–750.
9. Fletcher SE et al. Balloon angioplasty of native coarctation of
the aorta: midterm follow-up and prognostic factors. J Am
Coll Cardiol 1995; 25(3): 730–734.
10. Anjos R et al. Determinants of hemodynamic results of bal-
loon dilation of aortic recoarctation. Am J Cardiol 1992; 69(6):
665–671.
11. Bonhoeffer P et al. The multi-track angiography catheter: a
new tool for complex catheterisation in congenital heart dis-
ease. Heart 1996; 76(2): 173–177.

12. Joseph G, Mandalay A, and Rajendiran G. Percutaneous
recanalization and balloon angioplasty of congenital isolated
local atresia of the aortic isthmus in adults. Catheter
Cardiovasc Interv 2001; 53(4): 535–541.
13. Choy M et al. Paradoxical hypertension after repair of coarc-
tation of the aorta in children: balloon angioplasty versus
surgical repair. Circulation 1987; 75(6): 1186–1191.
14. Ussia GP, Marasini M, and Pongiglione G. Paraplegia follow-
ing percutaneous balloon angioplasty of aortic coarctation: a
case report. Catheter Cardiovasc Interv 2001; 54(4): 510–513.
472
Introduction
In most major pediatric centers balloon dilation of the aor-
tic valve in the cardiac catheterization laboratory is the
accepted standard for the primary treatment of aortic
valve stenosis. Balloon dilation of aortic valve stenosis to
treat valvar aortic stenosis was ﬁrst published in 1984
1
.
Balloon dilation of the aortic valve provides palliation that
is comparable to the palliation for similar aortic valve
stenosis achieved by a surgical aortic valvotomy, but
without the risks and morbidity of surgery
2,3
. Signiﬁcant
improvements in the dilation balloons, guide wires and
techniques over the past 15 years have improved the suc-
cess rate and decreased, but not eliminated, the morbidity
and mortality of the aortic dilation procedure for infants,
children and adolescents. The indications for dilation of

the aortic valve are similar to the indications for surgical
aortic valvotomy and, as with the indications for surgery,
the indications for balloon dilation vary with the age of
the patient.
In the newborn the diagnosis of aortic valve stenosis
comprises a very heterogeneous spectrum of anatomy,
including everything from a nearly atretic aortic valve
with a small aortic annulus and/or an associated very
small, hypoplastic left ventricle, to an equally stenotic
valve, but with a large, dilated poorly functioning left
ventricle. The exact anatomy and the resultant left ventric-
ular function determine the indications for balloon dila-
tion in this group. The echocardiographic demonstration
of aortic valve stenosis with associated poor left ventricu-
lar function or low cardiac output, particularly with an
otherwise “normal” sized left ventricle, is a major indi-
cation for intervention in a newborn regardless of the
measured gradient by either echo or catheterization
4
.
After the clinical evaluation along with a quality echocar-
diogram, the deﬁnitive diagnosis of valvular aortic steno-
sis is established by the hemodynamics obtained in the
catheterization laboratory. In the older infant and young
child with clinical ﬁndings of aortic valve stenosis, the
indication for valvotomy is determined from the peak to
peak hemodynamic gradient measured across the valve in
the catheterization laboratory. In the absence of any signs
of “poor ventricular function”, aortic valve dilation is per-
formed arbitrarily in very young children for a peak to

peak gradient greater than 65 mmHg across the valve.
Very young children do not participate in organized,
severely strenuous, or sustained physical activities and do
not create much additional gradient with their level of activ-
ity. In adolescent and adult patients, who are more likely
to participate in severely strenuous or sustained physical
activity, symptoms referable to the heart or a measured
peak to peak gradient across the valve of over 50 mmHg is
the arbitrary indication for valve dilation. These criteria
were established for a surgical aortic valvotomy on the
basis of “natural history” studies, and probably are too
conservative for balloon dilation of the aortic valve.
TechniqueCgeneral
General anesthesia with intubation and controlled venti-
lation is used in newborns, in critically ill patients with
aortic stenosis, and in any patient in whom the carotid
artery approach is being used. The same general proced-
ure is used for the “diagnostic” cardiac catheterization of
the patient who is not critically ill but who is undergoing
aortic dilation, as is used for the catheterization of any
other patient. The catheterization is performed under
deep sedation and local xylocaine anesthesia with supple-
mental sedation given intravenously periodically through-
out the procedure. A secure peripheral intravenous and
an arterial line are established and an indwelling “Foley”
catheter placed in the bladder in all patients past infancy
who are undergoing a balloon dilation of the aortic valve.
There are several different approaches and techniques
utilized to accomplish balloon dilation of a stenotic aortic
valve. The speciﬁc technique used depends upon the

19
Aortic valve dilation
CHAPTER 19 Aortic valve dilation
473
particular circumstances of each individual patient and
also on the individual preferences of the operator and/or
the catheterization laboratory. The aortic valve can be
approached retrograde from the femoral, brachial, um-
bilical, or carotid arteries. The aortic valve can also be
approached prograde from the right heart after passing
into the left heart through either a patent foramen ovale
or by crossing through the intact atrial septum with a
transseptal puncture. The atrial transseptal approach to
the left atrium is the preferred technique to acquire the left
heart hemodynamics and angiography when the atrial
septum is intact, while the retrograde approach through
the femoral arteries is the most commonly used approach
for the actual balloon dilation of the aortic valve. A double-
balloon dilation of the valve using a retrograde approach
from both femoral arteries is preferred for most aortic
valve dilations
5
.
Technique
For the combined prograde and retrograde approach to
the aortic valve dilation procedure, a short venous sheath
is introduced into one femoral vein and two very small
indwelling arterial cannulae are introduced into both the
right and left femoral arteries. The right heart catheteriza-
tion is performed using an angiographic “marker” catheter

introduced through the short venous sheath. When a
transseptal procedure is to be performed and there are
any concerns about or a peculiarity of any part of the
anatomy of the left heart, an angiocardiogram is per-
formed with injection into the pulmonary artery before
the transseptal puncture. The recirculation of the contrast
through the left atrium and left ventricle clearly demon-
strates the exact positions and any peculiarities of the left
heart anatomy.
The left heart hemodynamics are obtained by means of
a prograde left heart catheterization either through a pre-
existing interatrial communication or through a trans-
septal atrial puncture. Using the prograde approach to the
left heart, all of the hemodynamics, as well as quality, select-
ive left ventricular or aortic angiograms, are obtained
before any “time” is incurred in the arteries with the larger
indwelling arterial sheaths. When the necessary right
heart information has been obtained, the prograde venous
catheter is advanced into the left atrium and from there
into the left ventricle. Pressures are recorded from the left
ventricle and the femoral arteries, and the left ventricular
angiography is obtained to determine the severity and
type of the aortic stenosis.
In the absence of a pre-existing atrial communication,
the right heart catheter and short venous sheath are
replaced with a transseptal set of the largest French size
the patient can accommodate comfortably and safely. The
long sheath of the transseptal set should have an attached
back-bleed valve with a side arm/ﬂush port. A trans-
septal left atrial puncture is performed using the long

sheath/dilator transseptal set as described in detail in
Chapter 8. Once the long sheath is positioned in the left
atrium and the sheath and its back-bleed valve apparatus
are cleared meticulously of all air and clots, the side port
of the sheath is attached to the pressure/ﬂush system. At
this time in the procedure, the patient is given 100 mg/kg
of heparin through the long sheath. An angiographic
catheter one French size smaller than the sheath is advanced
through the sheath and manipulated from the left atrium
into the left ventricle. Simultaneous pressures are re-
corded from the left atrium, left ventricle and a femoral
artery. With the knowledge that the femoral artery pres-
sure can be as much as 20 millimeters higher than the aor-
tic root pressure as a result of the elastic recoil of the
systemic vasculature, this measured difference in pres-
sures between the left ventricle and femoral artery gives
an estimate, but does not give an accurate measurement of
the true transvalvular aortic gradient.
Following the transseptal puncture and when the initial
pressures have been recorded, a selective biplane angio-
cardiogram is performed with an injection into the left
ventricle. The angiocardiogram deﬁnes the precise
anatomy of the aortic root and the aortic valve stenosis,
and demonstrates any associated left ventricular outﬂow
track abnormalities. At least one view of the angiocardio-
grams should be as close to perpendicular to the valve
annulus as possible. The lateral (LAT) X-ray tube is placed
in a 60° left anterior oblique position with between 30° and
60° cranial angulation. The amount of cranial angulation
is determined by how horizontally the heart is situated

in the chestathe more horizontally the heart lies in the
thorax, the greater the cranial angulation. The posterior–
anterior (PA) X-ray tube is placed in a 30°, right anterior
oblique position with 30+° of caudal angulation. The PA
tube should be almost perpendicular to the LAT tube in
both planes. If the valve is not cut precisely on edge with
the initial picture, the X-ray tubes are rotated appropri-
ately and the angiocardiogram repeated. Very accurate
angiographic measurements are made of the diameter of the
valve annulus at the base of the aortic sinuses where the
valve leaﬂets attach or “hinge” in the annulus. The meas-
urements are obtained from a systolic frame where the
leaﬂets are open and the annulus is at its largest diameter
during the cardiac cycle. The measurements must be cali-
brated against a valid reference measurement system.
Depending upon the measurement system in the particu-
lar laboratory, an exact determination of the actual dia-
meter of the valve annulus is made or calculated utilizing an
accurate reference system for calibration of the measure-
ments. As discussed earlier in Chapter 11, the use of the
diameter of a catheter as the reference measurement is not
CHAPTER 19 Aortic valve dilation
474
satisfactory, and, in fact, creates dangerous errors when
measuring large structures such as valves and large ves-
sels. A calibrated “marker” catheter, which is positioned
exactly in the angiographic ﬁeld, is frequently used and
represents a very accurate reference system for calibra-
tion. The measuring “bands” on the calibrated catheter are
placed in the plane of the valve and aligned exactly per-

pendicular to the left ventricular outﬂow tract during the
injection for the valve measurement. The catheter tip can
be either in the aortic root, left ventricular outﬂow tract, or
even in the left ventricular apex. Often the catheter moves
during a pressure injection and as a consequence of this
movement, the “marker bands” on the catheter will usu-
ally align precisely on edge for the calibration measure-
ments during at least several frames of the angiogram. If
not, the catheter is repositioned to align the marks on edge
before either the X-ray tubes, the table or the patient are
moved and a very brief “cine” of the exactly aligned marks
is recorded with the new catheter position.
As an alternative, a “marker” catheter can be positioned
in the superior vena cava immediately adjacent to the aor-
tic root, and in this position it serves as a precise calibra-
tion reference in the same reference plane as the aortic
valve. The separate marker catheter in the superior vena
cava, simultaneously with the use of the transseptal tech-
nique, necessitates the use of an additional venous line for
the marker catheter. Similarly, a marker catheter can be
introduced into the esophagus with the “marks” posi-
tioned in a location immediately behind the cardiac
silhouette and adjacent to the aortic valve and, in that
position, used as an accurate reference system for calibra-
tion. Some X-ray systems have calibration marks embed-
ded in the image intensiﬁer screen. The changes in the
distance of these marks to the “isocenter” of the image are
computed constantly and accurately by the sophisticated
computer system, which allows the use of these marks for
a very accurate calibration reference regardless of the

position and distance of the intensiﬁer. When such a built-
in calibration reference system is available and it is
veriﬁed against a grid or marker catheter reference sys-
tem, it is the most convenient and accurate calibration
system available.
An external grid or a metal “sphere” of a known, precise
diameter placed in the exact plane of the valve as described in
Chapter 11 (Angiography) can also be used as the accurate
calibration reference. The external grid or sphere is a very
accurate but very inconvenient reference system.
Once the measurements of the valve annulus have been
completed, the X-ray tubes are placed in the positions that
will be utilized during the valve dilation. Biplane records
of the best images of the valve from both planes of the
biplane angiograms in this same angulation are stored in a
“freeze frame” to be used as a “road map” during the
valve dilation. If there is not a good “freeze frame” replay
capability available, it is useful to place tiny lead markers
on the chest wall exactly over the area of the aortic valve
annulus on the ﬂuoroscopic image. Fluoroscopy is used to
align the “lead” marks on the chest wall according to the
location of the valve as seen on the previous angiocardio-
grams in the same X-ray views.
The long transseptal sheath is advanced over the
catheter and into the left ventricle. An “active deﬂector
wire” is introduced through a wire back-bleed/ﬂush
valve into the original angiographic catheter and the
catheter is deﬂected 180° toward the aortic valve. While
holding the curve on the deﬂector wire and ﬁxing the wire
in place, the catheter is advanced off the wire, through the

left ventricular outﬂow tract, and into the aorta. This is
accomplished readily when an end-hole or angiographic
woven dacron catheter is used. These catheters become
very soft and ﬂexible after only a few minutes in the circu-
lation at body temperature, and as a consequence are relat-
ively atraumatic and easily deﬂected.
An alternative technique for advancing a catheter from
the left ventricle into the aorta is to use a ﬂoating balloon
catheter through the long sheath, which is positioned in
the left ventricle. The original angiographic catheter is
removed from the long sheath while the long sheath is
maintained in position in the left ventricle. The long
sheath is cleared thoroughly of all air and/or clot. The dis-
tal end of a ﬂoating balloon angiographic catheter, which
is at least one French size smaller than the sheath, is “pulled”
or softened in heat and then formed into at least a 180°
curve at the distal end. The balloon angiographic catheter
is introduced into the long sheath and advanced through
the sheath and into the left ventricle. During the introduc-
tion and the entire time the balloon catheter is being
advanced within the sheath, both the sheath and the
catheter are maintained on a constant ﬂush. Once the bal-
loon tip is beyond the sheath in the left ventricle, the
balloon catheter and sheath are switched to pressure
monitoring, the balloon is inﬂated with CO
2
, and usually,
using minimal manipulations, the balloon catheter ﬂoats
out of the left ventricle, across the stenotic valve, and into
the ascending aorta. In the presence of a very tight steno-

sis, the balloon must often be deﬂated partially, or even
completely, just beneath the valve in order for the catheter
to pass through the stenotic oriﬁce. Occasionally the
“active deﬂector wire” is used along with the ﬂoating bal-
loon catheter in order to redirect the catheter tip 180° away
from the apex and toward the valve.
Once a catheter has passed into the aorta, simultaneous
left ventricular, aortic root, and femoral artery pressures
are recorded, with the left ventricle pressure recorded
from the side arm of the sheath, the ascending aortic pres-
sure from the catheter, and the femoral pressure from
the femoral line. These pressures provide the true peak-
to-peak hemodynamic gradient across the valve and a
CHAPTER 19 Aortic valve dilation
475
comparison with the original left ventricle to femoral
artery pressures. In order to obtain even better visualiza-
tion of the valve leaﬂets, an aortic root aortogram is
recorded through this prograde catheter. The soft catheter
alone passing through the valve does not produce
signiﬁcant artifactual aortic regurgitation. When the aor-
tic root angiogram has been recorded, the prograde
catheter is advanced further out of the ventricle and the
tip advanced around the arch and into the descending
aorta (at least beyond the brachiocephalic trunk!). When
the hemodynamics have been recorded, both the catheter
and the transseptal sheath are placed on a slow continu-
ous ﬂush. The transseptal sheath remains in the left vent-
ricle and the catheter in the descending aorta before, during
and after the dilation procedure. This allows simultane-

ous aortic and left ventricular pressure monitoring and
recording during and immediately after the dilation proced-
ure. In addition, both the catheter in the aorta and the
transseptal sheath in the left ventricle serve as routes
for rapid infusions of intracardiac ﬂuids or medications.
Of equal importance, the shaft of the catheter that is pass-
ing through the stenotic oriﬁce of the aortic valve serves
as a visible and deﬁnitive “guide” for the subsequent
introduction of the retrograde wires/catheters across the
valve.
With the prograde catheters in place and the measure-
ments of the valve completed, the balloons for the dilation
are chosen and prepared. Extra long balloons are used for
balloon dilation of the aortic valve. For smaller patients
(and usually smaller 10 and 12 mm diameter balloons), a
4 cm balloon length is used, and for larger patients (and
usually larger balloon diameters), 6–8 cm long balloons
are used when available. The combination of the double-
balloon technique, the use of super stiff wires, and the use
of longer balloons, virtually eliminates the problem of the
balloons squirting or bouncing in and out of the valve and
further damaging the valve during the balloon inﬂations.
The combined inﬂated diameters of the two balloons for a
double-balloon dilation is equal to a maximum of 1.2 to 1.3
times the maximum accurately measured diameter of the
aortic annulus. If a single-balloon technique is used, the
single balloon diameter to start with is no more than 0.9 to
1 times the diameter of the accurately measured annulus.
For the usual balloon dilation of the aortic valve, the
balloons undergo a standard preparation in order to clear

them completely of any air before introduction into the sys-
temic circulation. A “minimal balloon preparation” simi-
lar to the balloon preparation in very small and/or
critically ill infants is used when there is concern that the
standard balloon prep would increase the deﬂated bal-
loon proﬁle enough to necessitate a larger arterial sheath.
The “minimal balloon preparation” is intended to clear a
balloon of air completely, but at the same time not to
“unfold” it from its “factory wrap” around the catheter.
With the prograde aortic catheter in place across the
valve and the dilation balloon(s) prepared, the inguinal
areas around the arterial puncture sites are re-inﬁltrated
liberally with 2% xylocaine. The indwelling arterial can-
nulae are replaced with sheath/dilator sets that will
accommodate the balloons chosen for the dilation. An
end-hole catheter that accommodates a 0.035″ guide wire
is passed retrograde around the arch and into the aortic
root from one of the arterial sheaths.
Crossing the stenotic aortic valve with the wire(s) and
then positioning the catheter(s)/wire(s) securely and
safely in the left ventricle is often the most difﬁcult part of
the aortic valve dilation procedure. The aortic root is often
very dilated and distorted, with the stenotic oriﬁce of the
valve located very eccentrically.
The course of the prograde catheter passing through the
stenotic valve from the left ventricle into the aorta pro-
vides the most reliable technique for identifying the exact
position and “direction” of the stenotic oriﬁce, and is a
valuable asset for crossing the stenotic aortic valve from
the retrograde approach. The course of the catheter pass-

ing through the valve oriﬁce provides a visible “guide” to
the actual course from the left ventricle, through the nar-
row and otherwise invisible oriﬁce, and into the aorta.
In the absence of a prograde catheter through the valve,
the valve leaﬂets themselves and the valve oriﬁce are
“invisible” on the ﬂuoroscopy and are only identiﬁed by
comparing the ﬂuoroscopic image to the “jet” of contrast
passing through the oriﬁce on the previous angiographic
recording. The “freeze frame” of that recording is used as
a guide in “ﬁnding” the valve oriﬁce during the retro-
grade approach.
A torque-control catheter with a preformed, slightly
curved tip, together with a steerable wire with a slightly
curved soft tip, are used to maneuver across the valve. A
preformed right or left coronary catheter is most useful for
directing the tip of the wire toward the aortic valve oriﬁce.
Occasionally the preformed retrograde catheter itself can
be directed purposefully and precisely along the course of
the prograde catheter and through the valve oriﬁce.
Usually crossing the stenotic oriﬁce requires the use of the
combination of several catheters and wires, even with a
prograde catheter serving as a guide. Rotating the shaft
of a catheter clockwise or counterclockwise with the
preformed tip positioned in the aortic root, moves the
catheter tip (and wire) anteriorly or posteriorly. Moving
the shaft of the catheter forward and backward moves
the curved tip of the catheter (and, in turn, the wire tip)
from side to side in the aortic root.
The prograde catheter passing through the valve oriﬁce
provides the exact “route” through the valve oriﬁce,

which is visualized simultaneously as the wire is manipu-
lated through the retrograde catheter. The combination
of the known location of the oriﬁce, which is delineated
CHAPTER 19 Aortic valve dilation
476
precisely by the course of the prograde catheter through
the oriﬁce, and the precise control over the direction of the
wire tip, allows the operator to maneuver the tip of the
wire purposefully, precisely along and immediately adja-
cent to the prograde catheter. In contrast to the rapid,
repeated maneuvers used during a “blind” probing with a
wire at a stenotic aortic valve, the maneuvers with the
catheter and the wire when “following along the prograde
catheter” are carried out slowly and purposefully. The tip
of the wire is observed frequently on both PA and lateral
ﬂuoroscopy as the wire is “tracked along” the prograde
catheter. This maneuvering of the wire into the ventricle is
still not “automatic” and may take several attempts, each
with a readjustment of the angle of approach of the wire to
the valve. Occasionally, when the angle of the valve oriﬁce
is very distorted, it is necessary to change to a catheter
with a completely different preformed curve at the tip in
order to angle the wire properly at the oriﬁce. A very soft
tipped wire can create a problem with this technique.
With a very tight stenosis, the high velocity of the jet of
blood through the oriﬁce, literally, blows the tip of a very
soft tipped wire away from the oriﬁce. When this problem
occurs repeatedly, a wire with a slightly stiffer tip is used
to accomplish the retrograde crossing of the valve. The
technique of tracking along the “adjunct” prograde

catheter to guide the retrograde wire through the valve
represents the most deﬁnitive technique available for cross-
ing the stenotic aortic valve from a retrograde approach.
Some operators prefer not to go through the extra
maneuvering for the adjunct prograde catheter technique,
and occasionally the prograde catheter from the left
ventricle into the aorta cannot be used or accomplished,
especially in very small, very sick infants. Various other
“tricks” are described for crossing the stenotic aortic
valves from the retrograde approach without the adjunct
prograde catheter. Most of the techniques ﬁrst involve the
positioning of a precurved, end-hole catheter retrograde
into the aortic root. An attempt is often made using the
retrograde catheter itself to probe at the “invisible” oriﬁce.
A soft tipped catheter is “bounced” gently, rapidly and
repeatedly off the valve and occasionally even “backs”
through a tight oriﬁce with a 180° loop formed on the
catheter. A catheter with a stiff tip should never be used
with this technique. A stiff catheter tip repeatedly
bounced off of a stenotic valve can easily create an oriﬁce by
perforating a leaﬂet!
When there is no prograde catheter through the valve, a
very soft tip, small diameter, spring guide wire is maneu-
vered toward the valve through a precurved, end-hole,
retrograde catheter, somewhat similar to the catheter/
wire maneuvers just described. The main difference is that
the wire is advanced rapidly and repeatedly, in and out of
the catheter tip while the angle of the catheter tip is
changed repeatedly. This, in turn, bounces, or backs the
wire tip in and out of the aortic sinuses until the tip or a

loop of the wire eventually falls (somewhat accidentally)
through the valve opening. Since the valve leaﬂets and the
oriﬁce are not visible at all, this requires rapid, but patient,
repetitions rather than any particular skill. The more
repetitive “probes” at the valveaeach with a change in the
direction of the wire by changing the catheter tip position
athe more likely is the chance of crossing the valve. This
is the opposite of tracking along a known course of a
prograde catheter through the valve and is an instance
where slow, meticulous catheter and/or wire manipula-
tions deﬁnitely are not indicated. Slow maneuvers in this
situation increase the radiation used and, at the same
time, decrease the “chances” of hitting the valve oriﬁce
per unit time of ﬂuoroscopy used. If one particular
wire/catheter combination does not accomplish crossing
the valve after several minutes of rapid “probing”, the
wire and/or the catheter is/are exchanged. A similar
“probing” at the valve with the new catheter/wire com-
bination is used.
Although a very soft tipped wire is unlikely to perforate
a valve cusp, there are potential problems associated with
the rapid probing technique. With the rapid in and out
movements of the wire, occasionally the wire drops
through the valve, but is pulled back and out of the ventri-
cle before the position is recognized because of the rapid-
ity of the maneuvering. This is even more likely in the
presence of a markedly distorted aortic root/valve or an
unusual course into the ventricle. A more serious problem
is the inadvertent and unrecognized cannulation of a
coronary artery with the wire/catheter. As the aortic root

is probed, the wire passes from the coronary sinus into
a coronary artery often more easily than through the
stenotic valve. In the presence of a markedly distorted aor-
tic root, the abnormal wire position in the coronary artery
can go unnoticed. When the soft tipped wire only is
advanced into the coronary artery, it usually does not
create a problem, but if the wire is advanced far into the
coronary, particularly if the catheter is advanced over the
wire deep into the coronary thinking it is in the ventricle,
the coronary artery can be damaged. The treatment for
this potential problem is awareness and prevention.
Perforation of an aortic valve leaﬂet during the retro-
grade probing of an aortic valve is a constant potential
problem. When the tip of the retrograde catheter is deep
into, or actually becomes buried in the aortic sinus and
then a wire is advanced out of the catheter tip, the wire
does not have room to “buckle” or bend and the wire is
then more likely to perforate directly through the valve
tissue in front of itaparticularly the tissue of a thin valve
leaﬂet. If a valve leaﬂet is perforated by the wire and then
a dilation balloon is passed over the wire through the per-
foration, the valve will be destroyed rather than dilated!
The stiffer the wire and/or the catheter that is used for the
CHAPTER 19 Aortic valve dilation
477
retrograde probing of the aortic valve, the less ability the
wire and/or catheter has of “buckling away” from the
aortic sinuses and the greater the potential for this type of
leaﬂet perforation. Even the “soft” tip of a “standard”
0.025″ spring guide wire is very stiff for the ﬁrst few mil-

limeters as it extends out of the tip of a catheter.
A Terumo™ (or Glide™) wire creates an equal or prob-
ably greater problem of perforation of the aortic leaﬂets
when it is used to pass retrograde across an aortic valve.
Terumo™ wires become much stiffer and much sharper
when they have no room to “buckle” between the tip of
the catheter and the structure/tissue it is attempting
to cross. The Terumo™ wire also “glides” through the
tissues easily once it does perforate, and as a consequence
an abnormal course of the wire within tissues can go
unrecognized.
The “blind” retrograde probing technique for crossing
the valve usually and eventually is successful, however, it
has obvious drawbacks. Crossing the valve depends more
on chance and multiple repeated attempts than on any
skill. The use of biplane imaging to help “identify” the
location of the oriﬁce in “three dimensions” is essential to
the success of this as well as all of the other techniques for
crossing the aortic valve. Even when the valve, and particu-
larly the oriﬁce of the valve, are not visible, the second
plane of ﬂuoroscopy allows the operator to know when
the catheter/wire is repeatedly probing in a totally inap-
propriate or non-productive area of a valve sinus.
Once the left ventricle has been entered with the retro-
grade catheter and/or wire using whatever combination
of retrograde wires, special catheters or special curves
happen to work most effectively in the particular patient,
a soft, curved tipped, spring guide wire is advanced retro-
grade as far as possible into the ventricle. When this wire
has been secured in the ventricle, an angled, end-hole

catheter is advanced over the wire into the ventricle. With
a combination of pushing and backing maneuvers of both
the wire and the catheter, the tip of the retrograde catheter
in the ventricle is deﬂected and directed 180° back toward
the aortic valve. When the angled end-hole catheter can-
not be directed fairly expeditiously back toward the aortic
valve, the original angled catheter is exchanged for a pig-
tail catheter over the original wire positioned in the left
ventricle. Once the pig-tail catheter passes over the wire
and the pig-tail curve is positioned securely in the left ven-
tricular apex, the original wire is removed and replaced
with the larger, long ﬂoppy tipped, preformed, stiff,
exchange length wire, which should almost automatically
point toward the left ventricular outﬂow tract when it is
advanced out of the catheter tip.
The largest diameter exchange wire that the balloon
catheters chosen for the dilation will accommodate is
introduced at this time. In larger patients, the exchange
wire is a 0.035″, Super Stiff™ exchange length wire with
a long ﬂoppy tip. This wire should have a “J” or, even, a
> 360° pig-tail curve formed manually at its distal ﬂoppy tip
and a second more proximal, smooth, but short 180° curve
formed at the “transition area” between the rigid part and
the ﬂoppy portion of the wire. The preformed 180° curve
at the transition area of the wire will allow the stiff portion
of the wire to be completely across the valve when the
180° curve at the transition area is seated in the apex of the
ventricle. Either the original retrograde, angled, end-hole
catheter looping 180° toward the outﬂow tract or the pig-
tail catheter in the apex of the left ventricle directs the tip

of the Super Stiff™ wire back toward the left ventricular
outﬂow tract and allows the 180° curve on the stiff portion
of the wire to “seat” in the apex of the left ventricle. The tip
of the wire is then directed back toward the LV outﬂow
tract or even back across the aortic valve.
When the double-balloon aortic dilation technique is
used, the catheter is left in position over the ﬁrst wire
and a slow ﬂush is maintained around the wire while the
second wire/catheter is positioned
5
. Once the ﬁrst stiff
wire is in a stable position, the opposite groin is inﬁltrated
liberally with xylocaine. A second sheath/dilator set is
introduced into the opposite femoral artery. An angled,
end-hole catheter, identical to the catheter which was ini-
tially used to cross the valve, is introduced into the second
arterial sheath and passed retrograde around the arch.
The second catheter is maneuvered retrograde through
the oriﬁce and into the left ventricle “following” the ﬁrst
catheter/wire precisely while using the course of the ﬁrst
wire/catheter through the valve oriﬁce to serve as a vis-
ible guide for introducing the second wire even if an
adjunct prograde catheter was not used. Once the second
wire has passed into the ventricle, the angled end-hole
catheter is advanced into the ventricle and curved back
toward the outﬂow tract similar to the positioning of the
ﬁrst catheter. When an 180° curve cannot be formed in the
ventricle with the angled end-hole retrograde catheter, it
is replaced with a pig-tail catheter, which is positioned in
the left ventricular apex adjacent to the ﬁrst wire. A sec-

ond teﬂon-coated stiff exchange wire is pre-shaped, ident-
ical to the ﬁrst exchange wire, passed through the second
catheter, and positioned in the left ventricle adjacent to
and in a similar position to the ﬁrst wire.
Once the two stiff wires are in a satisfactory, stable
position within the ventricle, the end-hole catheters are
removed over the wires and the previously prepared bal-
loons are introduced over the wires. It is important that
the wires are observed continuously and maintained pre-
cisely and securely in their positions during the introduc-
tion of the balloons through the sheath and during the
process of advancing the balloon catheters retrograde
around the arch. The portions of the wires that are outside
of the body are maintained straight and are ﬁxed against a
ﬁrm structure on the table (or against the patient’s leg)
CHAPTER 19 Aortic valve dilation
478
while the wires and the balloon catheters within the body
are observed frequently with ﬂuoroscopy. The wires out-
side of the body are adjusted in or out slightly in order to
keep the left ventricular wire loops from being withdrawn
from, or pushed further into (through!) the ventricle dur-
ing the various manipulations of the balloon catheters.
This is important particularly when the balloon catheters
are being maneuvered next to each other. The balloons are
maneuvered over the wires to a position just above the
aortic valve. The two wires are advanced toward the apex
of the ventricle until all “slack” is out of the wires and the
wires are pushed against the outer circumference of the
course from the descending aorta, around the aortic arch,

and into the ascending aorta.
Once all of the preparations are ready for the controlled
pressure inﬂation of the two balloons, the two wires are
ﬁxed in position and the balloons are advanced one at a
time over the wires and across the aortic valve. The posi-
tion of the balloons in the aortic valve is compared with
the “freeze frame” image of the valve. With the balloons in
their proper position, the area of the valve leaﬂets should
be exactly in the center of the two markers at the end of
each balloon. This positions the center of the parallel sur-
faces of the balloons at the narrowest portion of the valve.
If the balloons are unstable in the initial position across the
valve, they are advanced further over the wires toward
the apex of the ventricle while maintaining the parallel
walls of the balloons in the narrow portion of the valve
and keeping the curved wires in the apex of the left vent-
ricle. This readjustment is easier and safer when using
longer dilation balloons. If a balloon is too far within the
ventricle, the wire is advanced gently in order to push the
balloon back rather than withdrawing the balloon. This
maneuver maintains the wires at the “outer circumfer-
ence” of the course around the arch and maintains better
control over the wires.
In very severe valve obstruction, the passage of the ﬁrst
deﬂated balloon across the narrow oriﬁce can cause a sud-
den and dramatic deterioration in the patient’s hemody-
namics. In this circumstance, the ﬁrst balloon is positioned
rapidly in the valve, inﬂated, deﬂated and withdrawn
back into the aortic root. The patient is allowed to stabilize
(or is resuscitated) before attempting to position the sec-

ond balloon. The subsequent positioning of the two bal-
loons is accomplished as rapidly as possible and followed
immediately by simultaneous rapid inﬂation/deﬂation of
the two balloons. All inﬂations/deﬂations of the balloons
during a dilation procedure are recorded on either biplane
angiography or “stored ﬂuoroscopy”.
During the dilation, the balloons are inﬂated until the
indentations or “waists” in the balloons caused by the
stenotic valve disappear or until the balloons reach their
maximum advertised pressure, whichever comes ﬁrst. As
soon as the balloons reach this full inﬂation, they are
deﬂated as rapidly as possible. During the balloon inﬂation
in the aortic valve, almost total obstruction of all cardiac
output is created by the fully inﬂated balloon(s). The heart
rate slows, the systemic arterial pressure (monitored
through the prograde arterial catheter still passing
through the valve or through the side arm of one of the
arterial sheaths) drops, and the left ventricular pressure
(monitored through the transseptal sheath still positioned
in the ventricle) increases markedly. With a successful dila-
tion of the valve, these hemodynamic parameters rapidly
return to “normal” once the balloons are deﬂated, how-
ever, the balloons should be withdrawn rapidly over the
wires and back into the aortic root to be sure of, and to
facilitate, this recovery.
The inﬂation/deﬂation of the balloons is repeated sev-
eral times, changing the positions of the balloons before
each subsequent inﬂation by moving them in and out of
the valve slightly and, if possible, changing their relative
anterior/posterior/lateral relationships in the process.

With the pressures available through the long sheath in
the left ventricle and through the prograde catheter posi-
tioned in the aorta, the hemodynamic results of the dila-
tion are known as soon as the balloons have been deﬂated
and without moving the balloon catheters. The end point
of the dilation is the absence of any “waist” on the bal-
loons during the initial phase of subsequent inﬂations and
a reduction of the gradient across the valve to less than
25 mmHg. The left ventricular pressure should approach
normal or near normal as monitored by the indwelling
transseptal sheath(s).
Occasionally, the heart rate and blood pressures do not
return to normal very rapidly after the inﬂation/deﬂation.
When this return of heart rate/blood pressure is slow, or
appears non-existent, if not already accomplished, the bal-
loons are withdrawn over the wires, out of, and away
from, the valve. The patient is given atropine through the
left ventricle sheath and if necessary given several exter-
nal manual compressions to stimulate cardiac function.
With even partial relief of the aortic obstruction the heart
rate and pressure do return.
Before making the ﬁnal post-dilation hemodynamic
measurements, both balloons are withdrawn back over
the wires into at least the descending aorta so that the only
“equipment” passing through the valve is the two retro-
grade wires and the prograde balloon catheter, which is
positioned in the aorta. The residual gradient across the
valve is recorded from the pressure in the left ventricle
(through the sheath) and the pressure in the aorta
(through the prograde catheter) and/or one of the femoral

artery pressures through the side arm of the femoral
artery sheath. The pressure gradient and the contour of
the pulse curves give an excellent immediate indication of
the results of the procedure before the removal of any
catheters or wires. With a very successful relief of the
CHAPTER 19 Aortic valve dilation
479
obstruction, the left ventricular systolic pressure approx-
imates the aortic systolic pressure, the left ventricular end-
diastolic pressure is less than 15 mmHg, the gradient
across the aortic valve is abolished or reduced to less than
20 mmHg and there is little or no aortic valve regurgitation.
When mild, or no aortic regurgitation is produced, the
pulse pressure is 25–30 mmHg even with the prograde
catheter and the wires still across the valve. An aortic root
angiocardiogram to assess aortic regurgitation is recorded
with injection through the prograde catheter. This injec-
tion helps to assess the aortic regurgitation, particularly if
there is a wide pulse pressure. If there is signiﬁcant aortic
regurgitation but good relief of the obstruction, nothing
further therapeutic is performed in the catheterization
laboratory at this time. If there is a signiﬁcant residual gradi-
ent and signiﬁcant aortic regurgitation as demonstrated by
the post-dilation pulse pressure or the aortogram, the
wires are removed from across the aortic valve in order
to assess the aortic regurgitation more accurately. Occa-
sionally, a stiff wire is forced against one side of the annu-
lus and “holds the valve open”, creating false aortic valve
regurgitation. Once the wires across the annulus have
been withdrawn, the aortic regurgitation is reassessed

with repeat pressure measurements and a repeat aortic
root aortogram. The prograde catheter passing through
the valve alone does not, or very rarely, produce signi-
ﬁcant aortic regurgitation. However, if signiﬁcant aortic
valve regurgitation is demonstrated from the injection
through the prograde catheter, the prograde catheter is
withdrawn into the ventricle and a repeat aortic root
angiocardiogram performed with an injection in the aortic
root through a retrograde catheter. If there is still signiﬁc-
ant aortic regurgitation, regardless of any residual gradient,
no further dilation is performed.
If dilation with the original balloons did not produce
sufﬁcient relief of the obstruction, but also did not produce
signiﬁcant aortic valve regurgitation, the angiographic
images of the balloon inﬂations and the post-dilation
angiograms are reviewed. The diameters of the inﬂated
balloon(s) and valve annulus are re-measured accurately
on these angiograms of the inﬂations. If angiographically
the balloon diameters are the same or smaller than the
diameter of the annulus, the combined balloon diameters
are increased up to 1.2 times the annulus diameter and the
dilation repeated. If the balloon diameters are 1.2 times (or
more) larger than the aortic annulus on the angiographic
images of the balloon inﬂation, no further dilation is
attempted. If a single balloon is used for the dilation and
the balloon is exactly the same diameter as the annulus on
the inﬂation images, the balloon diameter is increased by
at most 10% and the dilation is repeated.
When the transseptal sheath and prograde catheter
were not used during the procedure, there are several

alternative techniques to record the postdilation pressures
before the wires are removed. A separate, new transseptal
procedure can be performed to enter the left heart and left
ventricle. The left ventricular pressure through the
transseptal catheter is compared with the femoral artery
pressure measured through the side arm of one of the
femoral artery sheaths. Another alternative technique is to
remove one balloon dilation catheter over the wire. The
wire is maintained in the left ventricle and the balloon
dilation catheter is replaced over this wire with a Multi-
Track™ catheter. The Multi-Track™ catheter is advanced
retrograde over the wire all the way to the left ventricle.
Pressures from the Multi-Track™ catheter can be
recorded from any location along the course of the wire
during either the introduction or the withdrawal of the
Multi-Track™ catheter and with the wire remaining in
place. Angiograms can also be recorded at any location
through an angiographic Multi-Track™ catheter. By using
the Multi-Track™ catheter, the retrograde wire is still in
place in the ventricle without any further manipulations
of the wire if a new balloon dilation catheter must be intro-
duced for a repeat dilation.
The third, and least attractive alternative to either of
these previous techniques for reassessment of the hemo-
dynamics post-dilation is to withdraw one of the retro-
grade balloon dilation catheters over the wire and
completely out of the body while leaving the wire in the
left ventricle. The balloon catheter is replaced with an end-
hole diagnostic catheter, which is passed over the wire,
retrograde, all of the way to the left ventricle. The wire is

then removed completely. The left ventricular pressure is
measured through this catheter and compared with the
femoral arterial pressure measured through the side arm
of the other arterial sheath. If the simultaneous pressures
following the dilation demonstrate an unsatisfactory
relief of the obstruction, an aortic root aortogram to assess
aortic regurgitation cannot be obtained without with-
drawing this catheter out of its position in the ventricle.
Once the catheter is withdrawn and if the dilation does
need to be repeated, one retrograde wire still is passing
through the valve and into the ventricle. This wire serves
as a “guide” along which the wire/catheter is directed
during the reintroduction of the retrograde catheter back
into the ventricle. Once the catheter is positioned back
in the ventricle, the stiff exchange wire is re-advanced
through this catheter and repositioned in the ventricle for
introduction of the new balloons.
Once it is determined that a satisfactory relief of
the aortic obstruction has been obtained, the balloon
catheters are withdrawn slowly over the wires and out of
the vessels. As they are withdrawn, the balloon catheters
are rotated in the direction of the balloon folds and
the negative pressure to the balloons is released during
the withdrawal through the aorta and out through the
sheaths.
CHAPTER 19 Aortic valve dilation
480
Occasionally the retrograde wires, with their pre-
formed loops and curves, become entangled in the ven-
tricular structures. Once the balloon catheters have been

withdrawn out of the sheaths, end-hole catheters are
advanced over the wires and into the ventricle. While
observing on ﬂuoroscopy, the wires are removed through
these catheters. Withdrawing them through catheters pre-
vents the wires from damaging or disrupting chordae or
papillary muscles around which they may have been
entrapped.
There is an additional technique for the guaranteed
introduction of a balloon dilation catheter retrograde
across even the most stenotic aortic valve. This technique
is used only when the aortic valve is particularly difﬁcult
or impossible to cross with any of the previous retrograde
catheter/wire techniques. This technique is most suitable
for a single-balloon dilation technique but can be used for
a dilation using double balloons. The technique is a varia-
tion of the use of the prograde catheter along with the ret-
rograde technique, but does add some additional complex
maneuvering to the procedure. An end-hole, ﬂoating bal-
loon catheter is introduced prograde into the left ventricle
through a long transseptal sheath. The end-hole balloon
catheter is advanced (ﬂoated) prograde across the aortic
valve and into the descending aorta. An extra long (400 cm),
exchange length, spring guide wire is passed through
the prograde catheter and into the descending aorta. A
snare catheter is introduced retrograde from a femoral
artery and the distal end of the prograde wire, which was
advanced through the prograde catheter, is snared with
the retrograde snare and withdrawn out through the
femoral artery sheath. This produces a “through and
through” wire from the femoral vein to the right atrium,

left atrium, left ventricle, through the aortic valve, into the
aorta, and out through the femoral artery. The desired bal-
loon dilation catheter is introduced over the arterial end of
the wire, through an arterial sheath, advanced retrograde
over the through and through wire and through the aortic
valve. For a double-balloon technique this procedure is
repeated from the other femoral artery and a second
femoral vein. The position(s) of the balloon(s) in the aortic
valve is/are adjusted with the catheters and wires and the
dilation of the valve carried out similarly to any other bal-
loon dilation of the aortic valve.
This technique guarantees that the balloon dilation
catheters cross the aortic valve oriﬁce and provides the
maximum control over the position and movement of the
balloons during the inﬂation/deﬂation. At the same time
it does add some complexity to the procedure. The
femoral artery and left ventricular pressures can be mea-
sured simultaneously before, during and immediately
after the dilation through a side arm of the transseptal
sheath and a side arm of the arterial introductory sheath
since, in order to accommodate the passage of even the
deﬂated dilation balloon, the sheath lumen is always
larger than the shaft of the balloon dilation catheter.
With the through and through wires in place, the bal-
loon dilation catheters are easily exchanged or removed.
Once the dilation of the aortic valve is completed success-
fully, the balloon dilation catheters are withdrawn over
the wires and replaced with end-hole catheters, which are
advanced retrograde over the wires and into the left ven-
tricular apex. Once the catheters are in place over the wires

the wires are withdrawn through the long sheaths from
the venous end. The retrograde catheters prevent the stiff
wires from cutting intracardiac structures when they
“tighten” as they are withdrawn.
When the catheters and wires have been withdrawn out
of the sheaths, more local anesthesia is administered liber-
ally around the sheaths at the arterial puncture sites, and
the sheaths are withdrawn. Direct manual pressure is
applied over the arterial puncture sites to stop local bleed-
ing. Either the dorsalis pedis or the posterior tibial pulse in
the same extremity as the puncture is palpated simultane-
ously while holding pressure on the artery, being sure that
the peripheral pulse is not obliterated by the pressure
applied to obtain the hemostasis. Pressure is maintained
balancing the control of bleeding vs. the peripheral pulse
until hemostasis is achieved. The systemic heparin is not
usually reversed, so achieving hemostasis safely after the
removal of a large sheath can take up to an hour or more.
After hemostasis is achieved, a very light bandage just to
cover the puncture site is applied. The bleeding should be
controlled before the bandage is applied. A tight compres-
sion pressure bandage is not used over the artery. The
bandage is left in place for 4–6 hours. The patient is
observed in a monitored recovery bed for a minimum of
four hours and until they are fully awake. Particular atten-
tion is paid to the puncture site and the pulses in the
extremity peripheral to the puncture site. The “Foley”
catheter is left in place until males are awake and until
females are moved out of the recovery ward. Patients who
undergo aortic valve dilation are observed in the hospital

overnight. On the assumption that all of the adrenergic
stress and any volume load from the catheterization are
dissipated by the following morning, these patients usu-
ally undergo an echocardiogram before discharge on the
day following the catheterization. This echo information
serves as the baseline, non-invasive value for subsequent
follow-up evaluations. The patient is discharged with no
imposed limitations because of the catheterization.
Infant and/or critical aortic stenosis dilation
The diagnosis of aortic stenosis is made from the clinical
ﬁndings and is based more on the appearance of the valve
by echocardiogram and the associated poor left ventricu-
lar function rather than on a “gradient”
4
. Dilation of aortic
CHAPTER 19 Aortic valve dilation
481
stenosis in the newborn or small infant is one of, if not
the most difﬁcult and dangerous procedures performed
by pediatric interventional cardiologists. The dilation of
infant aortic stenosis is not just a “small version” of any
other aortic valve dilation. The newborn or small infant
requiring treatment of aortic stenosis is usually very sick,
often is on prostaglandin and requires inotropic support
before and during the valve dilation procedure. The vas-
cular access is small, particularly in proportion to the
sheaths, catheters, wires and balloons that are available
for small infants.
These patients usually do have a patent interatrial com-
munication allowing the introduction of a prograde

venous catheter into the left ventricle. A left ventricular
catheter remaining in place throughout the procedure is
invaluable for pressure monitoring and, occasionally, for
a left ventricular angiocardiogram. In the very sick and
small infant, once the left ventricle is entered with the pro-
grade catheter, this catheter is not advanced further into
the aorta at this time unless a prograde approach for the
dilation is anticipated. When there is no naturally occur-
ring atrial communication, the decision is made at the
onset of the procedure as to whether acquiring the hemo-
dynamic information from the left ventricle before it is
entered retrograde is worth the extra effort and slightly
increased risk of a transseptal puncture in a very small
infant.
With meticulous attention to detail, patience, very delic-
ate technique, and some special instrumentation, percu-
taneous entry into a femoral artery essentially always is
accomplished, even in small infants. Small, sick infants are
the patients in whom the special 21-gauge percutaneous
needles and the extra ﬂoppy tipped 0.018″ wires are
invaluable for entering the artery (Chapter 4). A “single-
wall” puncture technique is always attempted. Once the
artery is cannulated with the guide wire, the surrounding
area to the puncture site is re-inﬁltrated liberally with
local anesthesia. A 3- or 4-French (depending upon the
balloon to be used), ﬁne or “feathered” tipped sheath/
dilator set is introduced into the artery. Once the sheath is
secured in the artery and cleared of any air, an end-hole,
pre-curved right coronary catheter is introduced through
the sheath and advanced retrograde to the aortic root.

The aortic pressures and aortic root angiocardiograms
are performed with the retrograde catheter. This catheter
allows baseline pressure measurements, and satisfactory
aortic root aortogram(s) can be obtained with end-hole
catheters in these small infants. At the same time, an
angled, end-hole catheter is the most useful for manipula-
tion of the guide wire across the stenotic valve for the sub-
sequent dilation, all without an unnecessary exchange of
catheters. Only one arterial catheter is necessary since a
single-balloon, retrograde approach is used for dilation of
the aortic valve in small infants. However, if the other
femoral artery is entered inadvertently during the punc-
ture of the vessels, it is cannulated with a 20-Gauge, teﬂon
Quick-Cath™ for continual arterial monitoring through-
out the procedure.
The “venous” catheter previously positioned in the left
ventricle along with the arterial line allows recording of
simultaneous left ventricular and aortic pressures. This
helps to conﬁrm the severity of the aortic stenosis, how-
ever, in these infants with poor left ventricular function,
the gradient, particularly in very severe aortic stenosis, is
often minimal. A left ventriculogram is not usually neces-
sary and potentially is dangerous in a critically ill infant. If
a ventriculogram is desired, it is recorded with injection in
the left ventricle through the prograde catheter. When the
left ventriculogram is accomplished before the valve is
crossed, it helps to localize the area of the valve oriﬁce.
The diameter of the aortic valve annulus is measured
very accurately from the aortic root injection or the left
ventricular angiocardiogram. Once the valve measure-

ments are obtained, the appropriate dilation balloon for
the aortic valve dilation is chosen and prepared before an
attempt is made at crossing the valve. The balloon chosen
is equal in diameter to the aortic annulus measured at the
valve hinge points. The preferred balloons for very small
infant and neonatal aortic valve dilations currently are the
very small Tyshak Mini™ (NuMED Inc., Hopkinton, NY)
balloons. The Tyshak Mini™ balloons up to 8 mm in
diameter pass through a 3-French sheath while the 9 and
10 mm Mini™ balloons require a 4-French sheath. The
Mini™ balloons, however, accept only a 0.014″ wire. The
Hi-Torque Iron Man™ wire (Guidant Corp, Santa Clara,
CA) is as effective a wire as any available for supporting
these balloons. The dilation balloon is prepared using a
“minimal prep” technique. The stenotic aortic valve is
crossed only after the balloon has been prepared and is
ready to be introduced. These infants are so precarious
that the 3- or 4-French catheter alone crossing the stenotic
oriﬁce is enough to occlude the oriﬁce and cause the infants
to decompensate acutely and occasionally irreversibly.
A 3- or 4-French, pre-curved right or left Judkins™
coronary catheter or a 3- or 4-French curve-tipped multi-
purpose catheter is advanced retrograde into the aortic
root from the femoral artery. To cross the aortic valves in a
neonate, a 0.014″ or a 0.018″ very ﬂoppy tipped exchange
length, torque-controlled guide wire is used. The wire
used depends upon what the balloon chosen for the dila-
tion will accommodate. When a 0.018″ wire can be used, a
Platinum Plus™ (Boston Scientiﬁc, Natick, MA) or a V-18
Control™ (Boston Scientiﬁc, Natick, MA) wire is very

useful both for crossing the valve and for supporting the
dilation balloon across the valve. A very slight curve is
formed at the tip of the wire to allow changes in direction
when torquing the wire. The wire is advanced through the
pre-curved catheter positioned in the aortic root.
CHAPTER 19 Aortic valve dilation
482
Crossing the aortic valve in the neonate is similar to
the “blind” crossing in an older patient except that all
structures are much smaller and, in turn, all catheter
manipulations are much ﬁner. Occasionally, the pre-
curved catheter will pass through the stenotic oriﬁce
when maneuvered directly at the valve. Crossing with the
catheter is attempted several times while simultaneously
rotating and moving the catheter in and out in the aortic
root. When the catheter does not cross the valve, the
catheter tip is positioned at least one centimeter above the
valve and the very soft tip of a ﬁne guide wire is manipu-
lated out of the catheter. The wire is directed toward the
aortic valve oriﬁce by almost continuously rotating the
catheter while simultaneously moving both the catheter
and the wire to and fro. Multiple, rapidly repeated, short
probes are made with the wire toward the aortic valve
oriﬁce rather than any slow, methodical maneuvers. The
exact location of this oriﬁce really is not known unless
another wire or catheter is already passing through the
valve. The more “probes” that are made with the wire
during the simultaneous, multiple changes in the angle/
direction of the wire, the more likely is the tip of the wire
to cross the valve. If the wire does not cross the valve after

several minutes of trying with the ﬁrst angled catheter
and wire, the catheter and/or the wire are replaced with
either the right or left coronary catheter or the multipur-
pose catheterawhichever was not used initiallyaand the
“probing” with the wire is repeated during continual
changes in the direction of the catheter tip. Eventually,
more by chance than skill, the wire crosses the valve into
the ventricle.
Once the wire crosses the valve, it is advanced as far as
possible into the ventricle, hopefully even looping the soft
tip of the wire within the apex of the left ventricle. With
the wire advanced as far as possible into the ventricle, the
catheter is advanced over the wire to the ventricular apex.
If the infant remains stable with the end-hole catheter
passed through the valve, the catheter is ﬁxed in the ven-
tricle and the wire is removed. Preferably, the original
ﬁne, soft tipped wire is replaced through the catheter posi-
tioned in the left ventricle with a stiffer, exchange length
wire of the largest diameter that the prepared balloon will
accommodate. The stiffer wire should be pre-shaped
before introduction into the catheter/ventricle. A “pig-
tail” curve is formed on the long ﬂoppy tip of the new
guide wire and a 180° curve, which conforms to the cavity
size at the ventricular apex, is formed at the transition
zone of the wire between the long ﬂoppy tip and the
stiff shaft of the wire. This speciﬁcally formed wire is
advanced through the catheter into the left ventricle. The
pre-formed “pig-tail” keeps the wire from digging into
the myocardium as it is manipulated within the ventricle.
The 180° curve at the transition area of the wire prevents the

stiffer wire from perforating the left ventricle and, at the
same time, directs the tip of the wire 180° back toward
the left ventricular outﬂow tract. This position allows the
stiff portion of the wire proximal to the curve at the trans-
ition area to be positioned completely across the valve
and deeper within the ventricle. With the wire maintained
in position, the catheter is removed and replaced with
the already prepared balloon catheter. The balloon is
positioned precisely across the valve and an inﬂation/
deﬂation is performed as rapidly as possible. The inﬂation/
deﬂation is recorded on biplane angiography or on
biplane “stored ﬂuoroscopy”.
During the inﬂation of the balloon, the left ventricular
pressure increases, the systemic arterial pressure drops,
and the infant develops bradycardia. As soon as the
deﬂation of the balloon is complete, the balloon is with-
drawn over the wire and out of the aortic valve. On relief
of the obstruction, the infant’s heart rate returns and the
left ventricular pressure decreases toward normal. The
rapidity of the stabilization of the infant is a partial indica-
tion of the success of the dilation. The infant’s heart rate
should return to a rate faster than the baseline rate and the
left ventricular pressure should be lower than predila-
tion. A very sick infant may require some medical or
mechanical assistance for return of the cardiac output.
When the infant does not remain stable with even the
small end-hole catheter across the valve, the original wire
used to cross the valve is stabilized rapidly and the
catheter is immediately withdrawn over the wire and out of
the valve oriﬁce while leaving the wire in place. The end-

hole catheter is rapidly replaced with the previously pre-
pared balloon dilation catheter, which is passed over the
wire and positioned across the valve as expeditiously, but
at the same time as accurately, as possible. Dilation of the
valve is carried out with as rapid an inﬂation/deﬂation of
the balloon as is possible. The balloon inﬂation/deﬂation
is recorded on biplane, stored ﬂuoroscopy or angiograph-
ically. After the inﬂation/deﬂation, the balloon is immedi-
ately withdrawn out of the valve, over the wire and into at
least the ascending aorta to allow the infant to stabilize.
The wire is kept securely in place in the ventricle when-
ever possible.
Once vascular access is obtained and the aortic valve is
crossed with a retrograde catheter, aortic valve dilation
from the femoral route usually is very successful.
However, femoral arterial access is the most difﬁcult and
the most hazardous part of the procedure in the neonate
and small infant. The vessels are very small relative to
even the smallest catheters/dilating balloons available for
aortic valve dilation. As a consequence, arterial complica-
tions are relatively common in this group of patients.
Although extreme occlusive problems with necrotic
ischemia of a limb are extremely rare, cool extremities
with poor perfusion of the extremity immediately after
a retrograde catheterization are common and usually
CHAPTER 19 Aortic valve dilation
483
represent compromise, if not total loss of the deep femoral
artery of the involved limb. These patients usually acutely
regain perfusion and warmth of the extremity but often on

subsequent attempts at access, the deep femoral artery is
totally occluded or occasionally the patient has a relative
growth failure of that extremity. As a consequence of the
femoral access problems several other routes for aortic
valve dilation have evolved.
Carotid artery introduction for the retrograde
approach
Transapical balloon dilation of the aortic valve in neonates
set a precedent for direct collaboration between the car-
diovascular surgeon and the interventional cardiologist
for performing aortic valvotomies in critically ill infants.
Because of the difﬁculties with arterial access and then
entering the ventricle from the femoral approach, particu-
larly with the earlier balloons, several centers performed
balloon dilation of the neonatal aortic valve in the operat-
ing room through a thoracotomy and a controlled, apical,
left ventricular puncture, but without the necessity of car-
diopulmonary bypass. Although this approach avoided
cardiopulmonary bypass, it did not avoid deep general
anesthesia, the thoracotomy, the ventricular perforation,
and all of the inherent problems of these particular proced-
ures. The improvement in balloons and balloon tech-
niques soon put this particular collaborative technique
to rest.
An alternative, unique and, initially, seemingly radical
collaborative approach for aortic valve dilation was devel-
oped as a consequence of the ongoing technical problems
with balloon dilation of the infant aortic valve and, at the
same time, other vascular technology which had been
developing concurrently. The continuing difﬁculties with

the arterial access site when using the femoral artery
approach in neonates and the persistent difﬁculties with
the catheter manipulation around the arch and across the
aortic valve from both the femoral artery and the umbili-
cal artery approaches made these approaches less than
ideal. At the same time the expanded use of extracorpo-
real membrane oxygenation (ECMO) led to almost “rou-
tine” cut-downs and repairs of the carotid artery by pediatric
vascular surgeons.
The combination of the persistent problems with the
femoral/umbilical catheter approaches and the proﬁciency
of the surgeons with the carotid cut-downs resulted in the
consideration of a carotid artery approach to the balloon
dilation of the aortic valve
6
. The carotid artery itself has
considerable appeal as an approach to the aortic valve. Of
most importance the approach to the aortic valve from the
entrance into the carotid artery is a very short, very
straight shot! With this “straight line” from the right
carotid artery to the left ventricle, minimal catheter
manipulation is required to cross even a severely stenotic
aortic valve and to enter the left ventricle with a wire or
catheter. The carotid artery is approached and entered
by a cut-down procedure performed and repaired by a
vascular/cardiovascular surgeon. The carotid approach
combined with essentially no vascular or central nervous
system sequelae when a skilled vascular surgeon exposes
and repairs the artery, makes the carotid approach seem
like the ultimate solution to a major problem.

Patients undergoing a carotid cut-down approach for
aortic valve dilations are anesthetized with general anes-
thesia to ensure that they are maintained absolutely still
throughout the procedure. They undergo endotracheal
intubation for control of their respiration and to keep the
head and face out of the “operating” ﬁeld in the neck. The
carotid approach for the dilation is usually used in con-
junction with a prograde catheter from a systemic vein
and a separate indwelling femoral arterial monitoring
line. The majority of the hemodynamic and anatomic
information is obtained through these lines before the
carotid cut-down is initiated. The venous catheter is
advanced through the patent foramen ovale (PFO) and
into the left ventricle in almost all of these infants. The
venous catheter and femoral arterial line are introduced
simultaneously while the surgeon is introducing the
sheath into the carotid artery and usually the prograde
catheterization and femoral lines do not add any over-
all time to the procedure. The prograde catheter and
indwelling arterial line actually simplify and add to the
safety of the procedure. The venous prograde catheter in
the left ventricle and the separate indwelling femoral arte-
rial line provide continuous left ventricular and systemic
arterial pressure monitoring before, during and after the
dilation without having to cross the aortic valve repeat-
edly with a retrograde catheter.
A vascular surgeon performs a cut-down on the neck
over the mid portion of the right carotid artery and iso-
lates the right common carotid artery. A ﬂoppy tipped
wire that will accommodate the balloon dilation catheter

is introduced into the artery either through a small inci-
sion performed by the surgeon or through a needle intro-
duced by the pediatric cardiologist.
The surgeon introduces a short 4-French sheath/dilator
with an attached back-bleed valve/ﬂush port into the
carotid artery over the soft tipped wire, and advances
it just to the base of the carotid artery as observed on
ﬂuoroscopy. All further introduction and positioning of
the sheath tip are performed by the pediatric cardiologist
and are visualized continuously on ﬂuoroscopy. If even a
short sheath is introduced to its hub in the carotid artery in
a small infant, the tip of the sheath extends to (or past) the
area of the aortic valve. If the tip of the sheath does not
pass through the oriﬁce of the valve, it potentially pro-
duces catastrophic damage to the aortic valve. Rarely, the
CHAPTER 19 Aortic valve dilation
484
sheath/dilator/wire passes into the descending aorta
from the right carotid artery cut-down and has to be with-
drawn and maneuvered speciﬁcally back into the aortic
root. Alternatively, the wire may pass directly into the left
ventricle during its initial introduction. When the sheath
is in the proper position in the ascending aorta, the dilator
and wire are removed and the sheath is cleared meticu-
lously of any air or clots before ﬂushing. The sheath is
secured in the artery by means of a purse string and sub-
cutaneous sutures so that the tip of the sheath is ﬁxed at
least 1–1.5 cm above the aortic valve. An aortic root aor-
togram is performed with an injection directly through
the sheath or through a catheter introduced into the

sheath. Accurate measurements of the valve annulus are
carried out using one of the reference calibration tech-
niques described in Chapter 11, “Angiography”. The
appropriate balloon for the valve dilation is chosen from
these measurements exactly as it is chosen for the femoral
approach. The balloon is prepared with a “minimal prep”
in order to eliminate all air from the balloon.
A soft tip exchange wire, with a very slight curve at
the tip, which will accommodate the prepared balloon
dilation catheter is introduced through the sheath. The
wire is introduced either directly through the sheath or
through an end-hole catheter introduced into the sheath
ﬁrst. A catheter within the sheath provides more control
over the tip of the wire and allows this catheter to be
advanced over the wire into the ventricle as soon as the
wire enters the ventricle. At the same time, the catheter
adds considerable “length” outside of the introductory
site into the carotid artery, and it extends well above the
infant’s head for the manipulations. The wire is manipu-
lated through the aortic valve into the left ventricle. This is
usually accomplished with only a few “probes” and mini-
mal readjustment in the direction of the wire tip. Once
through the valve, the wire is advanced deep into the
ventricle until the stiff portion of the guide wire is entirely
across the valve. The wire is ﬁxed in position in the ven-
tricle while the catheter is removed over the wire from
the sheath.
The balloon catheter is advanced over the wire, into the
sheath, and to the area of the valve. The balloon is cen-
tered precisely across the valve annulus as previously

identiﬁed by angiography or as visualized on a trans-
esophageal, or even a transthoracic, echocardiogram, and
a rapid balloon inﬂation/deﬂation is performed. The
inﬂation/deﬂation is recorded on a biplane angiogram or
on “stored ﬂuoroscopy”. The balloon is withdrawn over
the wire and back into the sheath immediately after it is
deﬂated. As with any other aortic valve dilation, the in-
fant’s hemodynamics deteriorate during the balloon inﬂa-
tion in the valve, but usually return rapidly to “normal”
(or better) with the deﬂation of the balloon and its with-
drawal from the valve. When the prograde left ventricular
and indwelling femoral arterial lines are in place, the
hemodynamic results of the dilation are available imme-
diately. The patient is allowed to stabilize while the
recording of the inﬂation/deﬂation is reviewed particu-
larly for the balloon position and the appearance/dis-
appearance of a waist on the balloon. When the infant’s
hemodynamics have stabilized, the balloon is reintro-
duced across the valve and the inﬂation/deﬂation is
repeated at least one more time. Before each reinﬂation,
the balloon is repositioned forward or backward in the
valve slightly. The balloon is observed for any persistent
“waist” on it during subsequent inﬂations, particularly
during the very initial phase of the inﬂation. After a
successful dilation, no residual waist should appear on
the balloon, even during the early phases of subsequent
inﬂations.
When satisﬁed with the appearance of the inﬂations
and the resultant hemodynamics, the balloon is with-
drawn over the wire and out of the sheath, and the sheath

is passively cleared very carefully of any air or clot. The
balloon dilation catheter is replaced with an end-hole
catheter, which is advanced into the ventricle over the
wire that is still positioned in the left ventricle. The wire is
removed slowly through the catheter, the catheter cleared
of air/clot and the simultaneous left ventricle and femoral
artery pressures are recorded. If a femoral line was not in
place or there was no prograde catheter in the ventricle,
the pressures are obtained following the dilation by either
a pull-back of the end-hole catheter across the valve or,
preferentially, with the left ventricular pressures obtained
through the catheter still positioned in the ventricle and
the arterial pressure obtained simultaneously from the
side port of the carotid artery sheath. In this case, the
sheath which is in the carotid artery/aorta must be at
least one French size larger than the catheter. When the
stenosis is not relieved by the initial dilation and aortic
insufﬁciency is not signiﬁcant, a wire is repositioned in
the ventricle (either through the catheter still in the ven-
tricle or by manipulating a wire/catheter back through a
valve), and the dilation repeated with a larger balloon or
with repositioning of the balloon. If a very wide pulse
pressure is recorded or massive aortic regurgitation is
visualized by echocardiogram, either the procedure is
concluded or the catheter is withdrawn into the aorta and
an aortic root angiogram is performed to verify the pre-
sence and amount of aortic regurgitation.
When the prograde catheter is already in the ventricle,
the pressures are recorded simultaneously from this
catheter, the femoral arterial line, and the sheath in the

aortic root. When there is no prograde catheter in the ven-
tricle, an end-hole catheter is advanced over the wire into
the left ventricle, the wire is removed, and the pressure
from the left ventricle is recorded through the catheter
with a simultaneous femoral artery pressure from the
CHAPTER 19 Aortic valve dilation
485
femoral arterial line. If the resultant pressure in the left
ventricle appears satisfactory compared to the femoral
arterial pressure, a “pull-back” pressure is recorded as the
catheter is withdrawn from the left ventricle into the aorta.
A follow-up aortic root aortogram is recorded with injec-
tion through the “retrograde” carotid catheter. The deci-
sion for any further ballooning of the valve is made
exactly as for other aortic valve dilations. When satisﬁed
with the results of the dilation, or if signiﬁcant aortic
regurgitation was created regardless of the residual gradi-
ent, the sheath is withdrawn from the artery and the artery
repaired meticulously by the vascular surgeon.
There are growing data indicating that the retrograde
approach to the aortic valve from the carotid artery may
be the safest and, in turn, the preferred approach for bal-
loon dilation of the aortic valve in very small infants. Once
the sheath is secured in the carotid artery, the carotid
approach represents the most expedient way of crossing
and dilating a severely stenotic aortic valve in an infant.
The results of the dilation are comparable to other dilation
techniques and there are no reported acute complica-
tions from the properly performed carotid approach. The
repaired carotid arteries have good Doppler ﬂow immedi-

ately following the dilation and on short-term follow-up
of the carotid repairs. Whether this technique is used rou-
tinely in any particular center depends upon the availabil-
ity and co-operation of the surgeon, the surgeon’s skill at
vascular access and repair, and the working relationship
between the surgeon and the interventional cardiologist.
When all of these “elements” fall into place, this is the pre-
ferred approach to the dilation of critical aortic valve
stenosis in the newborn and small infant.
Umbilical artery introduction for the retrograde
approach
In the newborn infant, at least one of the umbilical arteries
is potentially patent for up to a week (or more) after birth.
In a newborn infant with severe aortic stenosis who
requires aortic valve dilation, an umbilical artery ap-
proach for the retrograde catheter provides a potential
arterial access without compromise of a femoral or the
carotid artery
7,8
. The newborn with severe aortic stenosis
should have a venous catheterization with a prograde left
heart cardiac catheterization. After the ﬁrst few days of
life, the umbilical vein often is not accessible, in which
case the usual femoral vein approach is used for the
venous catheterization.
The infant with severe aortic stenosis usually is critically
ill and frequently already has an end-hole polyethylene
“umbilical artery” catheter positioned by the neonato-
logist in the abdominal aorta from one of the umbilical
arteries! In that situation, a ﬁne, very small diameter, but,

preferably, relatively stiff, exchange length, teﬂon-coated
wire is passed through the umbilical catheter and as far
as possible into the thoracic aorta, ascending aorta
and, with the ultimate luck, even into the left ventricle.
Unless the wire ends up in the left ventricle, the poly-
ethylene umbilical artery catheter is replaced over this
wire with a 4-French angled tipped (right coronary)
catheter.
When there is no pre-existing umbilical artery line, the
umbilical cord stump is scrubbed very thoroughly and then
“amputated” parallel with and close to the abdominal
wall. This exposes the stumps of the two umbilical arteries
and the umbilical vein. The two arteries are smaller in
diameter, rounder and thicker walled than the single,
larger diameter and irregular vein. Usually, all three of
these umbilical vessels are obliterated with thrombi,
however, patency of the arteries can often be restored
by “probing” the arterial lumen with a small diameter,
smooth and blunt tipped metal probe. One edge of the
exposed wall of the end of one of the arteries is grasped
with a small forceps and the occluded lumen of the artery
is probed with a very small, blunt, metal, vessel probe a
few millimeters at a time until the probe passes several
centimeters into the lumen. The probe usually stays
within the walls of the vessel as it dissects through the
thrombus. With the stump of the vessel opened in this
manner, an end-hole “umbilical artery catheter” is intro-
duced into the channel that was created with the probe,
and advanced into the newly opened vessel lumen while
placing some “counter tension” on the exposed edge of

the vessel with the forceps. As the catheter is introduced
into the lumen, it is directed posteriorly and caudally
toward the posterior pelvis. Once the catheter has
advanced several centimeters into the artery, it is visual-
ized on ﬂuoroscopy to determine whether the catheter is
being directed to the right or the left inguinal area. With
that information, the catheter is pushed in that direction
toward that groin and the “counter traction” on the
“stump” is pulled away from that direction.
Once the catheter has advanced one to two centimeters
within the artery, the vessel often seems to “open up” and
allow the catheter to move more freely through the umbil-
ical artery. Simultaneously, there may be blood return
into the catheter. Usually resistance is encountered in
maneuvering the catheter around the sharp 90–130° curve
at the junction of the umbilical artery and the iliac artery.
Occasionally, advancing the umbilical catheter is facilit-
ated by advancing a ﬁne, ﬂoppy tipped, torque wire or a
ﬁne, curved Terumo™ wire through, and slightly in
advance of, the umbilical catheter. Once the umbilical
catheter has advanced into the descending aorta, an
exchange length wire is advanced further into the thoracic
aorta, the ascending aorta and, as before, with consider-
able luck, into the left ventricle. If the wire does not
advance all of the way to the ventricle, the soft umbilical
CHAPTER 19 Aortic valve dilation
486
catheter is removed over the wire and replaced with a
4-French right Judkins™ coronary catheter.
From the descending aorta, the combination of the wire

and right coronary catheter is advanced/manipulated
around the aortic arch into the aortic root. This maneuver
is often very difﬁcult and requires several exchanges of
different wires and/or catheters. Once the catheter has
reached the aortic root, the wire is removed, the aortic
pressure recorded, and a biplane aortogram is recorded
with the X-ray tubes angled to “cut the valve on edge”
(some degree of LAO–Cranial and RAO–Caudal) with
the two planes. Accurate measurements of the valve
annulus are made using one of the various accurate X-ray
calibration techniques. A “marker catheter” can be placed
in the superior vena cava adjacent to the aorta or even the
left ventricle when there is prograde venous access. If
there is no venous line, a calibration marker catheter
can be inserted gently into the infant’s esophagus and
advanced to the area behind the cardiac silhouette as the
reference for the angiographic calibration system. When
positioned just behind the center of the heart shadow, the
calibration marks on the catheter in the esophagus are in
the plane of, and very close to, the aortic valve.
Once the measurements are complete, a very soft tipped,
ﬁne torque wire is inserted into the catheter and the
stenotic aortic valve is probed with the catheter/wire
combination. The technique is exactly as with any other
isolated retrograde approach to the aortic valve with the
exception that it is far more difﬁcult from the umbilical
artery. By the time the catheter/wire has been advanced
into the aortic root, the combination catheter/wire has
made two fairly acute and nearly 180° curves (passing
from the umbilical to the iliac artery and from the des-

cending to the ascending aorta). As a consequence, torque
control and to-and-fro control over the catheter are re-
stricted markedly. In addition, the “push” on the proximal
shaft of the catheter entering the umbilical artery must be
toward the groin and, counter-intuitively, “away” from the
direction of the aortic root. Finally, there frequently is
signiﬁcant arterial spasm along the course of the catheter,
which restricts catheter manipulation even further.
If the wire can be manipulated across the valve and well
into the ventricle, and depending on which wire is used to
cross the valve, an attempt is made at passing the catheter
into the ventricle. If the shaft of the original wire is relat-
ively soft, and depending upon the lumen diameter of the
dilation balloon catheter that is to be used, the initial wire
usually must be replaced with a wire which the dilation
balloon catheter can accommodate and which is stiffer in
order to support the delivery of a balloon/catheter
through the circuitous course. Once the proper wire is in
place, the catheter that is over the wire is placed on a con-
tinuous ﬂush through a wire back-bleed valve and the
appropriate balloon is prepared.
When the dilation balloon is ready, the original catheter
is withdrawn over the wire leaving the wire positioned
securely in the left ventricle. The balloon dilation catheter
is advanced over the wire into the umbilical artery and
through the circuitous course to the aortic valve. This fre-
quently cannot be accomplished or is only accomplished
with one or more exchanges of wires. When the bal-
loon is positioned accurately across the valve, a rapid
inﬂation/deﬂation is performed while recording the pro-

cedure on biplane angiography or stored ﬂuoroscopy.
When the infant stabilizes after the balloon deﬂation,
if possible, the balloon is left in place across the valve
until the angiograms of the inﬂation are reviewed. The
inﬂation/deﬂation is repeated at least one more time. The
reinﬂation/deﬂation veriﬁes that the “waist” on the bal-
loon does not reappear with the initial reinﬂation of the
balloon. If the infant does not stabilize rapidly after the
deﬂation with the balloon still across the valve, the bal-
loon is withdrawn into the ascending (or descending!)
aorta while simultaneously advancing the wire to main-
tain the wire’s position in the ventriclea if at all possible.
Once stabilized, an attempt is made at re-advancing the
dilation balloon across the valve for at least one more
inﬂation/deﬂation.
When the dilations have been completed, the balloon is
withdrawn over the wire, still leaving the wire in the ven-
tricle. The balloon catheter is replaced with an end-hole
catheter, which is advanced over the wire into the ven-
tricle. If there is no prograde catheter in the left ventricle,
the wire is withdrawn from the catheter, pressures are
recorded from the ventricle, and a biplane left ventricular
angiogram is performed through this catheter. Even
though the retrograde umbilical catheter is an end-hole
catheter, satisfactory left ventricular angiograms can be
obtained through these catheters in a neonate. A with-
drawal pressure tracing from the left ventricle to the
ascending aorta is recorded, following which an aor-
togram is performed in the aortic root to assess the move-
ment of the valve leaﬂets and the degree of aortic

regurgitation. The catheter is removed and the umbilical
artery stump is oversewn. When there is a prograde
venous catheter positioned in the left ventricle during the
procedure, the pre- and post-left ventricular pressures
and any left ventricular angiograms are obtained through
this catheter. The prograde catheter obviates the necessity
of multiple recrossing of the valve with the umbilical/
retrograde catheter.
Because of the difﬁculties in maneuvering the catheters,
wires and balloons from the umbilical artery approach
and now with the much smaller balloon dilation catheters
that can be introduced into the femoral arteries through
very small (3- or 4-French) sheaths, the umbilical artery
approach is no longer attempted in our center, although it
is still used as the preferred approach in some centers.
CHAPTER 19 Aortic valve dilation
487
Prograde approach to aortic valve dilation
There still are difﬁculties, particularly in smaller patients,
in using any arterial approach for aortic valve dilation.
The various potential problems from the different arterial
approaches led to the development of techniques for the
venous approach for the prograde delivery of the dilation
balloon(s) to the aortic valve for aortic valve dilation. The
usual prograde approach to the left heart is with catheters
introduced from the femoral veins, although the umbil-
ical veins have been used in neonates and the jugular/
brachial veins have been used in the presence of a pre-
existing interatrial communication. These approaches
obviate virtually all of the particular problems with the

arteries that occur with the arterial approaches, but they
do have some signiﬁcant difﬁculties of their own
9,10
.
Prograde catheterization of the left ventricle and the
aorta through a pre-existing intracardiac communication
or by means of a transseptal atrial puncture are techniques
that are used very commonly. The use of a diagnostic
catheter which is advanced prograde into the aorta after it
has been introduced into the left heart through a trans-
septal atrial puncture is part of the routine procedure for
dilation of the aortic valve in the older patient as described
earlier in this chapter. When a prograde dilation of the
aortic valve is anticipated, two additional measures are
necessary. First, when the transseptal puncture is per-
formed, the transseptal sheath (set) that is used must
be large enough in diameter to accommodate the largest
dilation balloon catheter that is to be used for the prograde
aortic valve dilation. Secondly, the passage of the catheter
from the left atrium to the left ventricle initially is accom-
plished using a “ﬂoating” balloon catheter. The inﬂated
balloon of a ﬂoating balloon catheter is more likely to ﬂoat
preferentially through the true, central oriﬁce of the mitral
valve, cleanly between the papillary muscles, and away
from any chordae. This is essential in order to avoid the
eventual passage or expansion of the relatively large dila-
tion balloons through narrow channels in, or entangled
with, these valve structures.
The hemodynamic data are recorded and angiography
performed in both the left ventricle and the aorta through

the prograde catheters as described earlier in this chapter.
Once the hemodynamics and angiography are completed
and it is established that aortic valve dilation is indicated,
a long transseptal sheath is advanced over the ﬂoating bal-
loon catheter and positioned securely in the left ventricle as
near to the apex as possible. If a double-balloon technique
is to be used, a second, appropriately sized, long trans-
septal sheath is introduced into the left atrium and the left
ventricle in a similar fashion to the ﬁrst long sheath. Either
an end-hole, ﬂoating balloon or torque-controlled catheter
is advanced through each long transseptal sheath. As the
catheter tip reaches the tip of the sheath, the sheath is
withdrawn very slightly to allow the tip of the catheter
to exit the sheath without digging into the ventricular
myocardium. The catheter(s) is(are) manipulated from
the left ventricle, 180° into the aorta, around the arch
and well into the descending aorta using the techniques
described earlier. The end-hole catheter used for this can
be either a soft, torque-controlled catheter or an end-hole,
ﬂoating balloon Swan™ type catheter. A ﬂoating balloon
catheter is usually easier and safer to use for this manipu-
lation, although the smaller ﬂoating balloon catheters do
not accommodate a 0.035″ guide wire.
When the end-hole catheter(s) has/have been advanced
well into the descending aorta, an exchange length guide
wire is introduced into each catheter through a wire back
bleed valve. With the catheter on a slow continuous ﬂush,
the wire is advanced through the catheter and positioned
securely in the descending aorta. The exact wires used
depend a great deal on the size of the patient and the type

and size of balloons to be used. Whenever possible, a relat-
ively stiff wire is desirable in order to provide support for
the passage of a balloon catheter around the two 180°
curves en route to the aortic valve and to hold the bal-
loon(s) in place during the dilation. At the same time, the
wire cannot be so stiff that it holds the mitral valve open
and that it “straightens” the normal 360° course from the
right atrium to the aorta into a straight line! Occasionally
the stiff wire will not traverse around the curves through
the original prograde catheter to the aorta or, even if the
wire can be positioned in the aorta, it is so stiff that it holds
the mitral and/or aortic valves open or “splints” the ven-
tricular walls apart. Any of these difﬁculties with the wire
interferes with the ventricular function to such a degree
that it cannot be left in place for even a few minutes. The
wires in their course from the left atrium, through the ven-
tricle, to the aorta must have a long loop, deep into the
apex of the left ventricle and must not pass across the ven-
tricular cavity. The wires must be maintained in that posi-
tion throughout the dilation procedure in order to prevent
damage to the mitral valve.
Once the appropriate wires are in satisfactory, stable
positions and the patient still remains stable, the catheter(s)
remain(s) over the wire(s) while all of the catheter(s)
and/or the long sheath(s) in the left ventricle are main-
tained on a slow continuous ﬂush while the dilation
balloon(s) are prepared. The dilation balloon for the pro-
grade approach should be shorter than those used for a
retrograde aortic valve dilation. The shorter balloons facil-
itate the delivery of the relatively stiff “balloon segment”

of the balloon dilation catheter through the tight curves
in the circuitous prograde course to a position across the
aortic valve. The shorter balloons also help to ensure that
the proximal ends of the balloons are positioned entirely in
the left ventricular outﬂow tract and well away from the
mitral apparatus when they are inﬂated. After a balloon is
CHAPTER 19 Aortic valve dilation
488
prepared, the original catheter is removed over the wire
while maintaining the wire in its position well into the
descending aorta and through the long sheath and, at the
same time, the tip of the sheath is maintained near the left
ventricular apex.
Each balloon dilation catheter is introduced over the
wire into the long sheath in the femoral vein and
advanced to the aortic valve, all of the time maintaining
the sheath and the catheter lumen on a continuous ﬂush.
This circuitous route through two 180° curves within the
heart usually takes considerable and meticulous manipu-
lation of both the catheters and wires while maintaining
the sheath in position securely within the left ventricle.
Care must be taken that the wire loops neither tighten nor
elongate excessively on themselves. When the wires begin
to tighten, they pull against, and cut into, the valvular
structures and begin to pull the tips of the wires back out
of the aorta. When the loops of wire elongate excessively
they “stent” the valvular structures open or cut into the
valves along the “outer circumference” of the loops. The
long sheath maintained in position deep within the left
ventricular apex makes the balloon passage from the

left ventricle to the aorta slightly more difﬁcult, but this
position of the sheath is essential to help prevent mitral
valve damage.
When a wire repeatedly pulls back from the aorta
and cannot be maintained in the descending aorta as
the balloon dilation catheter is advanced over it, a snare
introduced retrograde is used to hold the wire in place. A
Micro Vena™ snare catheter is introduced into a femoral
artery through a 4-French sheath. The distal end of the
prograde wire in the descending aorta is grasped with a
10 mm Micro Vena™ snare introduced retrograde. The
wire is held securely with the snare in this position,
which secures the distal end of the prograde wire in the
descending aorta. Alternatively, the distal end of the pro-
grade, exchange length wire is withdrawn through the
descending aorta and “exteriorized” through the femoral
arterial sheath. Either the snare catheter holding the
prograde wire or the exteriorized distal end of the wire is
secured on the table outside of the artery. When a pro-
grade, double-balloon dilation is being performed, the
second wire also is grasped with a retrograde snare. This
can be performed through the same femoral artery with
the same snare grasping the two wires simultaneously or
with a second snare through the opposite femoral artery.
When a single snare catheter is used, unless the ﬁrst wire
or both wires is/are “exteriorized”, the exact tension on
the separate wires cannot be controlled separately.
If a retrograde sheath/catheter cannot be introduced
into a femoral artery for the snare catheter, or the intro-
duction is contraindicated, an attempt is made at manipu-

lating the prograde wire all the way around the arch, to
the descending aorta and into one of the femoral arteries,
advancing the tip of the wire to a position well beyond the
inguinal ligament. The prograde wire can often be ﬁxed
in this position by ﬁrm, manual, ﬁnger pressure directly
over the artery, compressing the artery and, in turn, secur-
ing the wire in the inguinal area. This ﬁxes the wire but
does not allow any “counter traction” or other change in
position or tension on the wire from the distal end.
The through and through control on the wire with the
retrograde snare keeps the wire from being pulled out of
the aorta and back into the left ventricle as the balloon is
being advanced. At the same time, the loops in the wire
passing through the heart with traction at both ends of the
wire, can “tighten” the loops dangerously about the struc-
tures in the heart. For many reasons, signiﬁcant tightening
of the wires must be avoided. If the bare wires tighten,
they cut into the structures “within” the loopsain particu-
lar the medial leaﬂet of the mitral valve, the mitral chor-
dae, the left ventricular outﬂow tract and/or the aortic
valve itself. As the loops of the wires tighten, the wires
pull across the sub-valve apparatus of the mitral valve.
If the wires remain across the sub-valve apparatus of the
valve as the balloon is advanced, the larger diameter,
rougher surfaced, balloon also passes through or is
expanded in the sub-valve mitral apparatus causing dis-
ruption of the apparatus. The long sheath across the mitral
valve helps to protect the mitral valve but does not guar-
antee that the mitral valve cannot be severely damaged.
Even when the tightening loops do not cause injury, the

“tightening” and, therefore, narrower loops in the wire
create more resistance to the movement of the balloon
catheter over the entire course of the wire. The tighter the
course of the wire loops, the more difﬁcult the passage of
the balloon becomes. The most extreme and dangerous
degree of “tightening” of the loops of the wire results in
the wire starting from its previous 360° course while pass-
ing from the inferior vena cava, to the right atrium, left
atrium, left ventricle and out into the aorta, actually
straightening into an entirely straight course through the
same structures! This occurs with a sudden “ﬂip” of the
wire and unequivocally will damage intracardiac struc-
tures. This very dangerous phenomenon is prevented by
the continual observation of the course of the wires and
never allowing the “loops” in the wires to begin to tighten.
The signiﬁcant difﬁculties with the passage of a balloon
dilation catheter over the wire require an exchange of the
original wire for a smaller diameter wire or a wire with
entirely different characteristics. The prograde delivering
of the balloon on the balloon dilation catheter to the valve
is the most difﬁcult part of this procedure.
Once the balloon is positioned across the aortic valve,
any wire loops or curves that were tightened excessively,
are “loosened” by advancing the wire very carefully. The
proximal end of the prograde balloon across the aortic
valve must be positioned cephalad in the left ventricular

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