Ebook Clinical manual and review of transesophageal echocardiography (2nd edition): Part 2

PERICARDIAL D I S EASES

45. Properties of the parietal pericardium include:
a. Collagen fibers meshed with elastic fibers
b. Flexibility
c. Rigidity in older patients
d. Lining of the fibrous pericardium
e. All of the above
46. The inflammatory phase of pericarditis is marked
by all of the following except.
a. Infiltration with leukocytes such as lymphocytes,
polymorphonuclear leukocytes, and macrophages
b. Alterations in pericardia! vascularity
c. Deposition of fibrin
d. Decrease in pericardia! fluid content
47. In patients over 60 years of age, the D wave of pul­
monary vein flow Doppler examination is generally
greater in magnitude than the S wave.

I

369

a. True
b. False
48. In constrictive pericarditis, the thickened pericardium
isolates the intrapericardial cardiac chambers (but not
the extrapericardially located pulmonary veins) from
changes in intrathoracic pressure during the respira­
tory cycle.
a. True

b. False
49. Prominent hepatic vein diastolic flow reversal may
be noticed as a result of increased RA pressure only
in patients with significant tricuspid regurgitation
and sinus tachycardia.
a. True
b. False


Ec h oca rd i og ra p hy fo r
Ao rti c S u rg e ry
Christopher Hudson, Jose Coddens, and Madhav Swaminathan

INTRODUCTION
Diseases involving the aorta can present a challenge to
both surgeons and anesthesiologists. Aortic dissection
and rupture are life threatening, require rapid and accu­
rate diagnosis, and need definitive medical and/or sur­
gical management due to their high risk of morbidity
and mortality. 1 •2 A key ingredient in the efficient man­
agement of these patients is imaging of the thoracic
aorta. Transesophageal echocardiography (TEE) has
become an essential noninvasive diagnostic modality for
acute thoracic aortic pathologies, and is a standard part
of the echocardiographer's armamentarium in the oper­
ating room. 3-6 It is important for the echocardiographer
to quickly and accurately verifY the diagnosis, distinguish
true pathology &om the many common confounding
artifacts, and clearly communicate precise echocardio­
graphic findings of the aorta and related cardiac anatomy

to the surgeon in order to guide intervention. The follow­
ing text reviews aortic anatomy and pathology and associ­
ated echocardiographic features that assist with imaging
during aortic surgery.

ANATOMY OF THE AORTA
In order to truly appreciate the invaluable role that TEE
plays in the assessment for diseases of the aorta, a
detailed understanding of the aorta and surrounding
anatomic structures is crucial. The thoracic aorta can
be divided into three anatomic segments: ascending
thoracic aorta, aortic arch, and descending thoracic
aorta (Figure 1 6- 1 ) . The ascending thoracic aorta orig­
inates at the level of the aortic valve annulus. As previ­
ously described in Chapter 9, the aortic valve com­
prises three crescent-shaped leaflets that coapt to form
three commissures. Immediately distal to the aortic
valve apparatus is a short and dilated aortic segment­
the sinus of Valsalva-which is subdivided into the
noncoronary, left coronary, and right coronary sinuses.
As the nomenclature suggests, the left and right coro­
nary arteries each originate from their respectively
named sinus. Distal to the sinus of Valsalva, the aorta

slightly narrows, forming the sinotubular j unction
(STJ) . From this point, the ascending aorta crosses
beneath the main pulmonary artery, then courses in an
anterior, cranial, and rightward direction over the ori­
gin of the right pulmonary artery.
The ascending aorta terminates and continues as the

aortic arch at the origin of the brachiocephalic (innomi­
nate) artery. The aortic arch then proceeds to curve in a
posterior and leftward direction with cranial convexity.
Three arteries arise from the aortic arch: the brachia­
cephalic, left common carotid, and left subclavian arter­
ies. It is often difficult to visualize the distal ascending
thoracic aorta and proximal aortic arch with TEE
because the trachea is positioned between the esophagus
and aorta, effectively preventing ultrasound transmission.
Immediately beyond the origin of the left subclavian
artery, at the point of attachment of ligamentum arteria­
sum (remnant of the fetal ductus arteriosus), is a second
narrowing called the aortic isthmus. Unlike the heart
and proximal part of the aorta, the aortic isthmus and
descending thoracic aorta are relatively fixed. Conse­
quently, deceleration inj ury secondary to trauma is
most often confined to this level. Distal to the aortic
isthmus, the descending aorta follows a caudal, slightly
anterior, and rightward trajectory towards the aortic
diaphragmatic hiatus. Along its intrathoracic course,
the descending thoracic aorta and the esophagus are in
close proximity. While the esophagus courses almost
straight downward, anterior to the midline of the ver­
tebral bodies, the aorta travels in a smooth, curved
direction from the anterolateral side of the 4th thoracic
vertebral body to the anterior side of the 1 1 th vertebral
body.
During its thoracic descent, multiple intercostal
arteries branch off the aorta and may occasionally be
imaged with TEE using color-flow Doppler (CFD) .

Spinal branches of these intercostal arteries supply
blood to the spinal cord through radicular arteries. The
radicular artery anatomy in this area is quite variable,
with 4 to 1 0 radicular branches typically contributing
to the thoracic spinal cord. The anterior spinal cord
blood supply is tenuous in the thoracic region, thus it is


ECHOCARDIOGRAPHY FOR AORTIC SU RGERY

Trachea
Brachiocephalic a.
Subclavian a.

I

37 1

left and right sides of the aorta, slightly below the
mesenteric vessels.
The wall of the aorta is composed of three tunicae:
the intima, media, and adventia. The inner layer, the
intima, consists of simple squamous epithelium and
underlying connective tissue. The tunica media consists
of circularly arranged smooth muscle and elastic tissue.
The outer adventitial layer is mainly a loose layer of con­
nective tissue, lymphatics, and vasa vasorum (ie, "vessels
of the vessels") . TEE provides the ability to assess the aor­
tic wall for many pathologies including thickening of the
tunica intima due to arteriosclerosis and/or atherosclero­

sis, intimal tears/dissections, and aneurysmal dilatation.

ECHOCARDIOGRAP HIC EVALUATION
OF THE THORACIC AORTA

FIGURE 1 6- 1 .

Anatomic cou rse of the thoracic aorta.
The relations h i p with the esophagus is particularly
i m portant with regard to orientation of the probe and
the aorta i n each of its thoracic sections: the ascending
aorta, aortic arch, and descending aorta. The i nterposi­
tion of the trachea makes portions of the ascending
aorta and arch either completely invisible or partially
visible.

at great risk for cord ischemia. Frequently, one radicular
artery-the arteria radicularis magna, or the artery of
Adamkiewicz-is very developed and is responsible for
the majority of anterior spinal cord blood supply, and it
is typically found between T9 and T l 2 .
Below the diaphragm, the abdominal aorta lies
posterior to the stomach. Because the stomach is a
large cavity that is highly deformable, the position of
the abdominal aorta in relation to the intragastric
TEE probe is somewhat variable. The celiac artery and
mesenteric arteries originate from the anterior side of
the abdominal aorta. The renal arteries arise from the

As described in Chapter 5 , insertion of the TEE probe

must be performed gently and should never be forced
through areas of resistance. This is especially important
in patients with suspicion of major aortic pathology.
First, intubation of the esophagus with the TEE probe
can be very stimulating and may result in hypertensive
episodes, increasing the risk of further tearing or rup­
ture of a dissection or aneurysm. Second, resistance
encountered during advancement of the probe may rep­
resent esophageal compression by a large aneurysm, and
if so, consideration should be given to abandon the
examination. Finally, in aortic dissection, because the
adventitia is the sole layer of the wall of the false lumen,
aortic rupture may occur if the TEE probe is not
manipulated cautiously.
As with any TEE examination, a systematic approach
is required to thoroughly evaluate the thoracic aorta. As
per the SCA/ASE guidelines, there are six short-axis and
two long-axis imaging planes that enable imaging of
most of the thoracic aorta? Although many sequences
are possible, the authors recommend the following order:
Begin with the midesophageal (ME) aortic valve (AV)
short-axis (SAX) , "Mercedes-Benz'' view, which is
obtained at the midesophageal level with the scan angle
rotated forward to 30° to 60° (see Figure 5-1 9B) . From
here, the angle can be rotated by another 90° to about
1 20° to 1 50° to identify the ME AV long-axis (LAX)
view (see Figure 5-20B) . The long-axis view is particu­
larly important because it allows evaluation of the aortic
valve and proximal ascending aorta. Measurements can
be made of the left ventricular outflow tract (LVOT), aor­

tic valve annulus, sinuses of Valsalva, STJ, and ascending
aorta if aortic valve repair and/or root reconstruction are
planned (Figure 1 6-2) . In order to visualize the ascend­
ing aorta in short axis, rotate back to a scan angle of 0°
and slowly withdraw from the level of the aortic valve (ie,
ME ascending aorta SAX view; see Figure 5-30B) . By
rotating forward to a 1 20° scan angle, a ME ascending


372

C H A PTER 1 6

A

B

FIGURE 1 6-2. Midesophageal aortic va lve long-axis view shown as a mid-systolic frame (panel A) and with rele­
vant measurements (pa nel B). See text for deta i ls.(AV, aortic va lve; LVOT, left ventricular outflow tract)

aorta LAX view is obtained (see Figure 5-32B) . It is
crucial in these two views to carefully examine the aorta
for dissections. Artifacts are frequently encountered
within the ascending aorta, and it is important to dis­
tinguish artifacts from true pathology as discussed in
Chapter 3 .
Following examination o f the ascending aorta, the
TEE probe should be advanced to the level of the ME
four-chamber view and rotated towards the patient's
left. This should result in the descending aorta SAX

view in which the aorta appears as a circular image at
the top of the screen (Figure 1 6-3) . AB the descending
aorta is about 3 to 4 em in diameter at this level, reduc­
ing the scan depth to 6 to 8 em and selecting a high
transducer frequency improves both the spatial and
temporal resolutions of the image. Almost the entire
descending thoracic aorta may be visualized in short
axis by advancing and withdrawing the TEE probe. By
rotating the scan angle forward to 90°, the descending
aorta can be seen longitudinally (see Figure 1 6-3) .

FIGURE 1 6-3. Short- (left)
and long-axis (right) views of
the descending aorta shown
simu lta neously with x-plane
imaging.


ECHOCARDIOGRAPHY FOR AORTIC SU RGERY

Alternating between short- and long-axis views may
help demonstrate aortic pathology more comprehen­
sively. While withdrawing the TEE probe and main­
taining the descending aorta in the short-axis view
(at 0°) , the aorta will change in appearance from circu­
lar to longitudinal at the level of the aortic arch (upper
esophageal [UE] aortic arch LAX; see Figure 5-34) .
Frequently, the origins of the left subclavian and carotid
arteries can be seen. Adding CFD with the Nyquist

limit set at 50 cm/s may aid in visualizing these vessels.
Finally, by rotating forward to 90°, the UE aortic arch
SAX will be obtained (see Figure 5-3 1 B) . Most aortic
pathologies can be identified by adding pulsed-wave
Doppler (PWD) and continuous-wave Doppler (CWD),
as well as gray-scale and color M-mode to the two­
dimensional (2D) examination above.

AORTIC ANEURYSMS
An aortic aneurysm is a localized or diffuse dilation of
the aorta to twice its diameter involving all three layers
of the vessel wall. The estimated annual incidence is six
cases per 1 00,000 persons. 8 TEE is useful for the diag­
nosis and classification of thoracic and upper abdomi­
nal aortic aneurysms. Thoracoadominal aneurysms
(TAAs) are categorized into four types based on the
Crawford classification system (Figure 1 6-4) .9 Type I
involves the entire descending thoracic aorta to the
abdominal aorta above the renal arteries. Type II origi­
nates in the proximal descending thoracic aorta and ter­
minates distal to the renal arteries. Type III affects the
distal half of the thoracic aorta and the abdominal aorta
to the bifurcation. Type IV is limited to the distal por­
tion of the descending thoracic aorta and the abdomi­
nal aorta to the bifurcation.

I

3 73

Aneurysms are generally thought to be a disease of
aging and a consequence of degeneration and athero­
sclerosis. Aging results in a pathological process that
involves the development of eccentric fibrous intimal
thickening, lipid deposition, and calcification, leading
to weakening of the aortic wall and dilation. 1 0 Accord­
ing to Laplace law (Tension = Pressure X Radius), as the
diameter of the lumen increases, the wall tension
increases resulting in progressive dilation. Other causes
ofTAAs include connective tissue diseases (ie, Marfan's,
type IV Ehlers-Danlos and Loeys-Dietz syndromes) ,
infections (ie, bacteria, mycotic, or syphilitic) , trauma,
and increased wall tension secondary to hypertension or
a high-velocity jet originating from aortic stenosis.
The decision to surgically repair a TM is based
upon the size and etiology of the aneurysm. According
to recommendations by the Society of Thoracic Surgeons,
a thoracic fusiform aneurysm should be surgically
repaired if it is greater than 5 . 5 em in diameter or twice
the diameter of the normal contiguous aorta. 1 1
Indications for saccular aneurysm have not been deter­
mined, but it is considered reasonable to intervene if
the width is greater than 2 em. Patients with connective
tissue diseases, such as Marfan's syndrome, may be con­
sidered for early operative repair because of their
increased risk of dissection or rupture. A strong family
history of aortic aneuryms may also prompt early inter­
vention. Finally, symptomatic patients should be
considered for operative treatment regardless of the size
of the aneurysm. Symptoms include persistent pain,

malperfusion, and compression of nearby structures
leading to dysphagia, cough, hoarseness, or Horner's
syndrome. Descending TAAs can also be treated by
endovascular stent grafting. There are no established
guidelines regarding which patients should be managed

D i ssect i o n s

FIGURE 1 6-4.

Classifica­
tion of aortic d issection and
aneurysms.

D e Bakey
Type

I

Type II

Stanrord Type A

Type

Il

Type B

Crawlord

Type I

crawrord
Type II

Crawlord
Type Ill

crawrord
Type IV


3 74

C H A PTER 1 6

with endovascular aortic repair (EVAR) . In general,
patients at high risk for complications from either con­
ventional open repair or medical management may bene­
fit from this relatively less invasive approach. Another
emerging alternative for complex aortic pathology is the
"hybrid" approach in which an open surgical technique
is combined with an EVAR. This approach is thought
to maximize the benefit of complete repair of com­
plex lesions while minimizing the risk of a total open
technique.
TEE may be used to detect the patency of aortic side
branches and to evaluate for the presence of organ
malperfusion. In the thoracic region, the identification
of the left subclavian artery and its patency may be par­

ticularly important in EVAR and hybrid approaches.
Intraoperative TEE is also an excellent monitoring tool,
especially if aortic cross-clamping is performed, and
may be helpful during cannulation if total or partial
extracorporeal circulatory support is required. Monitor­
ing of cardiac function is an added benefit of TEE dur­
ing aortic aneurysm surgery. While the aorta remains
the focus of intraoperative imaging, the effects of aortic
manipulation on cardiac function can also be evaluated.
This enables clinicians to make informed decisions on
pharmacological support, should it be required.

AORTIC DISSECTION
An aortic dissection is a separation in the aortic wall
that allows blood flow within the tunica media. Cur­
rently, there are two proposed etiologies for aortic dis­
sections. 1 2 In the first hypothesis, the intima is rup­
tured along the edge of an atheromatous plaque or at a
penetrating ulcer. The high pressure in the aorta forces
blood through the intimal tear into the tunica media,
creating a false lumen. The intimal layer that separates
the false lumen from the true lumen (normal conduit of
blood in the aorta) is termed the intimal flap. While
intimal injury per se does not lead to dissection, it is a
common precipitating factor, especially when the aortic
medial layer is diseased. In the second hypothesis, the
dissection is attributed to spontaneous rupture of the
vasa vasorum or degeneration of the collagen and
elastin that make up the tunica media. This medial
layer can be affected by poor structural integrity as seen

in old age or with primary connective tissue diseases
such as Marfan's syndrome. Apart from medial
integrity, the time required for extension of an intimal
tear and development of a dissection depends on the
rate of rise of systolic pressure, pulsatile pressure, dias­
tolic recoil, and mean arterial pressure.
Aortic dissection is the most common cause of death
among all conditions involving the aorta. The incidence
of thoracic aortic dissection in North America is about
5 to 1 0 cases per million people per year. 1 3 The mortality

associated with acute aortic dissection is extremely high,
with 2 1 % of patients dying before hospital admission. 14
The mortality rate from acute aortic dissection has
been shown to be 1 o/o to 3% per hour for the first 24 to
48 hours, and as high as 80% by 2 weeks. 1 5 Due to this
high mortality, early diagnosis is considered crucial for
appropriate management to be initiated.
Magnetic resonance imaging (MRI) is currently the
gold standard test for the detection and assessment of aor­
tic dissections with a sensitivity and specificity of 98% and
98%, respectively. 16 However, there are many contraindi­
cations to MRI examination including implanted medical
devices (ie, pacemaker, orthopedic hardware, etc) and
hemodynamic instability. Consequently, TEE is increas­
ingly becoming an important and convenient modality for
diagnosis of acute aortic dissection. TEE, similar to MRI,
is highly sensitive and specific for the diagnosis of aortic
dissection, with a sensitivity of 97% and specificity of
1 00%. 1 7 TEE is an attractive first-choice diagnostic proce­

dure because of its accuracy, speed, relatively low cost,
portability, and noninvasiveness. 18 However, a major
limitation ofTEE in the diagnosis of aortic dissection is
the inability to reliably visualize the distal ascending aorta
and proximal aortic arch. The frequent presence of arti­
facts such as mirror images in aortic imaging makes TEE
prone to important false-positive diagnoses of dissection
(Figure 1 6-5) .
There are two main classification systems utilized for
thoracic aortic dissections (see Figure 1 6-4) . 1 9 The
DeBakey classification system recognizes three types of
aortic dissections. 1 9•20 In type I, the entire aorta is dis­
sected; in type II, only the ascending aorta is involved;
and in type III, the ascending aorta and arch are spared,
while the descending aorta is dissected. Type III is fur­
ther subclassified into type IliA, involving the descend­
ing thoracic aorta alone, and type IIIB, extending into
the abdominal aorta. The Stanford system classifies dis­
sections into two types. 20 In Type A the ascending aorta
is affected, while in Type B the ascending aorta is
spared. A classification system from Europe has also
been proposed to replace the DeBakey and Stanford
classification systems. 2 1 •22 This classification groups dis­
section into five types based on etiology (Table 1 6- 1 ) .
These classification systems have important prognos­
tic and therapeutic consequences. 1 1 •23 Type A aortic dis­
section is a formal indication for surgical intervention
because the reported mortality rate with medical therapy
far exceeds that reported for surgical treatment. 24-26
Unlike Type A aortic dissections, the correct manage­

ment for Type B aortic dissections remains controver­
sial. 27-29 Medical management is advocated for most
Type B dissections as most studies show no clear survival
advantage with surgical management. Some indications
for surgery in Type B dissection include organ malper­
fusion, persistent pain, hemodynamic instability, or


ECHOCARDIOGRAPHY FOR AORTIC SU RGERY

I

375

FIGURE 1 6-5. Mides­
ophagea l ascending aortic
long-axis view with a suspi­
cious shadow (?) in the aortic
l u men. The pul monary a rtery
(PA) catheter may cast a m ir­
ror image artifact in the
ascending aorta that d isplays
a similar"bou nce"to that of
an intimal flap, creating a n
i m pression o f a dissection.
Similarly, a n actua l dissection
flap may be erroneously m is­
taken for an artifact.

any signs of impending or ongoing rupture, notably

the accumulation of pleural, pericardia!, periaortic,
or mediastinal fluid; propagation of the dissection;
increasing size of hematoma; and development of a
saccular aneurysm. In addition, echocardiographic evi­
dence of a wide-open false lumen with communication
to the true lumen increases the risk of progression of
the dissection, and therefore is considered an indica­
tion for surgery.
Though an intimal tear is the classic finding for aor­
tic dissection, it is not always present. The presence of
an intimal flap is therefore considered a classical sign of
dissection, but not a mandatory one. The TEE exami­
nation of a patient with aortic dissection involves sev­
eral components including characterization of the dis­
section, assessment of flow in aortic branches, and
determination of cardiac complications. The dissection
flap is a thin, mobile echogenic membrane found within
Table 1 6- 1 . E u ropea n Society of Card i o logy
C l assification of Aortic D i s sectio ns.

Class
I
II
Ill
IV
V

Description

Classic aortic dissection (DeBakey and Stanford)

I ntramural hematoma/hemorrhage
Discrete/subtle dissection without hematoma
Plaque rupture leading to aortic ulceration
Traumatic or iatrogenic

the aortic lumen; however, t o avoid a false-positive
diagnosis, the intimal flap must be identified in multi­
ple image planes. 1 8·30 ,3I Although identification of the
site of the intimal tear can be challenging, CFD imag­
ing is useful in the assessment of entry and exit sites. It
can sometimes be very difficult to distinguish the true
lumen from the false lumen. In contrast to the false
lumen, the true lumen tends to be smaller, round in
appearance, shows enlargement during systole, and
often has normal PWD and CFD profiles. In addition,
M-mode imaging can help determine the direction of
movement of the flap in systole, and thereby identify
the location of the true lumen (Figure 1 6-6) . The false
lumen is usually larger and crescent shaped, and often
demonstrates spontaneous echo contrast suggesting
sluggish blood flow.
Closure of the tear to prevent further spread of the
dissection is an essential part of the surgical repair. 32
Ascending aortic dissection usually requires a formal
sternotomy, while descending aortic dissections can be
managed by open (thoracotomy) , EVAR, or hybrid
techniques. The two most common sites of intimal tear
are 1 to 3 em above the sinuses of Valsalva (70%) and
the ligamentum arteriosum (30%) .33-35
Other variants of aortic dissection include intra­

mural hematoma (IMH) and aortic ulcers. Intramural
hematoma (ie, European Heart Society class II dissec­
tion) is a common finding with a prevalence of up to
30%. 3 6 ·37 The false lumen is believed to be due to
rupture of vasa vasorum in the tunica media resulting


3 76

C H A PTER 1 6

Tech niq ues of determining flow i n the true l u men. Pa nel (A) is a two-d imensional midesophageal
long-axis view of the descending aorta showing two possible l u mens. The appl ication of color-flow Doppler (panel 8)
demonstrates higher velocity flow in the true l umen. M-mode imaging across the long axis of the aorta (panel C)
demonstrates the two sides of the true l u m e n expa nd in g in systo le as the intra l u m i n al pressure i ncreases. Color
M-mode imaging (panel D) shows color-flow signa ls within the true l u men i n systole corresponding with the
expanding l u men in pa nel (C).

FIGURE 1 6-6.

in hematoma formation. 1 2 There are two distinctive
types of IMH. 3 8 Type I IMH has a smooth intraluminal
surface, a diameter less than 3.5 em, and a wall thick­
ness greater than 0 . 5 em, while type II IMH has a rough
intraluminal surface, a diameter greater than 3 . 5 em,
and a wall thickness greater than 0.6 em. Both types
have a longitudinal extension of at least 1 1 em.
Atherosclerotic aortic plaques can also ulcerate
(ie, European Heart Society class IV dissection) leading
to the formation of aneuryms, aortic rupture, or dissec­

tions. 39 The ulcers predominantly affect the descending
thoracic aorta and are not usually associated with longi­
tudinal extension. On TEE, these lesions are characterized

by a discrete ulcer penetrating the aortic wall with or
without intramural hematoma.
While identification and characterization of the
dissection remains extremely important, there are
several other crucial aspects of the echocardiographic
examination for a patient with aortic dissection.
Functional aortic insufficiency (AI) occurs frequently
in patients with acute Type A aortic dissection, with
approximately 44% being severe AI. 5 The mecha­
nisms of the AI include incomplete leaflet closure
due to leaflet tethering in a dilated aorta, aortic
leaflet prolapse due to disruption of leaflet attach­
ments, and dissection flap prolapse through the


ECHOCARDIOGRAPHY FOR AORTIC SU RGERY

aortic valve orifice. The management of AI associ­
ated with aortic dissection is controversial . If the aor­
tic valve leaflets are otherwise normal, preservation
of the native valve can be achieved in up to 86% of
Type A dissections.4o
The aorta has several side branches, including the
_
coronary artenes,
cerebral vessels, celiac and mesenteric

vessels, renal arteries, and spinal cord vessels, which can
be compromised as a consequence of dissection. The
incidence of coronary artery involvement in aortic dis­
section can be as high as 1 0% to 20%.41 The left main
�nd r!ght coronary arteries can often be reliably visual­
Ized m the ME AV SAX viewY Direct evidence of
coronary involvement is the presence of a dissection
flap_ exten�ing int? the ostium of the coronary vessel.
Indirect evidence mcludes electrocardiographic (ECG)
changes, cardiovascular instability, and echocardio­
graphic findings of regional wall motion abnormalities.
Although branch arteries of the aortic arch can be reli­
ably visualized with TEE,42 .43 the use of additional
modalities including epiaortic scanning and surface
Doppler directly over the carotid arteries to assess dis­
section extent into the arch vessels is highly recom­
mend�d. 44 �he remaini�g side branches including the
renal, mtestmal, and spmal cord vessels are more diffi­
cult to examine with TEE.
Other important echocardiographic findings include
the presence of pericardia! and left pleural effusions.
Although peri�ardi� effusions can result from the rup­
ture of the dissection through the wall of the aortic
root, the most common cause is from the transudation
of fluid across the false lumen. 4.45 The development of
left pleural effusion is similar except for the fact that the
rupture occurs in the descending thoracic aorta.46 , 47
A pericardia! effusion appears as an echolucent space
between the parietal and visceral pericardium on TEE.
Echocardiographic signs suggesting tamponade include

early diastolic collapse of the right ventricle, late dias­
tolic/early systolic collapse of the right or left atrium,
decreased size of the cardiac chambers, and abnormal
ventricular septal wall motion with inspiration. A left
pleural effusion is best seen in the descending aorta SAX
view as an echolucent space that resembles a "claw"
(Figure 1 6-7) .
Intraoperatively, TEE is a valuable tool to monitor
volu �e status and global and regional left ventricular
funcuon. It can also assist with cannulation and discern
whether the malperfused side branches originate from
the false or the true lumen-information that is essen­
tial in the surgical decision to reimplant these vessels.
Finally, TEE can be used to evaluate the success of the
surgical repair (ie, absence of blood flow in the false
lumen) and assess for the presence of residual AI and
resolution of wall motion abnormalities or pericardia!
and pleural effusions.

I

377

FIGURE 1 6-7.

Midesophageal short-axis view o f the
descending aorta demonstrating a crescent-shaped
echol ucent s pace that suggests a sig n ificant left pleural
effusion.

AORTIC ATHEROSCL EROSIS
Stroke continues to be a significant cause of morbidity
and mortality after cardiac surgery. Strokes occur in
approximately 1% to 6% of patients following cardiac
surgery and account for nearly 20% of deaths.48-50 The
association between aortic atheromatous disease and
stroke _ has been clearly defined.5 l-53 Techniques for
detectmg the presence of aortic atheromas include
manual palpation, x-ray, magnetic resonance and tomo­
graphic scans, and cardiac catheterization. However,
TEE and epiaortic ultrasound are generally considered
to be superior imaging modalities.54.55
�everal classification systems for grading the severity of
aortic a�eromas have been proposed. A commonly used
system IS that of Katz and colleagues who divided the
severity of atherosclerosis into five grades (Table 1 6-2) . 52
It should be noted, however, that these measurement
and categorization schemes are limited because they

Table 1 6-2. C l a ssification of th oracic a o rtic
athero m a .

Grade
1

2

3

4

5

Description

Normal aorta
Severe intimal thickening
Atheroma protruding <5 mm into aortic lumen
Atheroma protruding >5 mm into aortic lumen
Mobile atheroma


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C H A PTER 1 6

measure only maximal thickness and do not account for
total plaque area (ie, "atheroma burden'') within any given
segment of aorta. Furthermore, the thickness measurement
is just a one-dimensional estimate of a three-dimensional
atherosclerotic lesion. Another limitation of grading
systems is that gray-scale density, calcification, surface
texture, and ulceration are highly subjective atheroma char­
acteristics and prone to interobserver variability. Irrespective
of the specific classification system used, patients with
advanced aortic atherosclerosis are at high risk for adverse
outcomes-patients with grade 5 lesions have a 1 -year
mortality rate of25%.525 6
Although TEE has been useful in diagnosing aortic
atheromatous disease, it is not without limitations. The
usual site for aortic cannulation and cross-clamping

during cardiopulmonary bypass is the distal ascending
aorta and proximal arch, which are difficult areas to
visualize with TEE.57·5 8 It is also believed that aortic
manipulation may result in plaque embolism and sub­
sequent neurological injury. 59 It is therefore possible to
miss the presence of severe aortic disease with TEE
alone. Konstadt et al found that severe atherosclerosis in
the ascending aorta was not detected in 1 9% of cases. 57
Epiaortic ultrasound has been shown to overcome this
limitation and has emerged as the gold standard for
detecting the extent and distribution of ascending aortic
atherosclerosis. 44• 60 It is important to note that although
it is possible to accurately detect atheromatous disease
with a combination of TEE and epiaortic scanning, any
subsequent alteration in surgical management has not
been conclusively shown to reduce the incidence of neu­
rological sequelae. 61 · 62 There are numerous surgical tech­
niques that focus on reducing the manipulation of the
ascending aorta in an effort to decrease embolic events.
These include using alternate atheroma-free sites for can­
nulation, cross-damping, and placement of proximal
anastomoses; deep hypothermic circulatory arrest for
improved neurologic protection; off-pump approaches;
and avoidance of cross-damping altogether. 60 ,63 -66

AORTIC TRAUMA
Traumatic aortic disease is associated with an exception­
ally high mortality. 67· 68 The reported mortality rate of
patients who present to the hospital with a traumatic
aortic injury is about 30%. Severe deceleration is the

most common etiology, with the injury most commonly
occurring at the aortic isthmus (approximately 54% to
67% of the time) . 67 Other sites of injury, in order of
decreasing frequency, are the descending thoracic aorta,
the aortic arch, and the abdominal aorta. Computed
tomography (CT) scan and aortography remain the
diagnostic imaging modalities of choice. 69 However,
these modalities can be time consuming, require trans­
port of a potentially unstable patient, and necessitate

administration of nephrotoxic contrast agents. In con­
trast, TEE, with a reported 9 1 o/o sensitivity and 1 00%
specificity, is noninvasive, can be performed at the bed­
side, and avoids the use of contrast agents, but may also
be limited by availability of suitably trained personnel. 6
Three types of lesions may be encountered: a subad­
ventitial traumatic aortic rupture, a traumatic aortic inti­
mal tear, or a mediastinal hematoma. 6 The subadventitial
traumatic aortic rupture may be partial, subtotal, or
complete, and is characterized by the presence of blood
flow on both sides of the disruption. A flap consisting of
intima and media can also be found. There may be a
disrupted aortic wall and a deformed aortic contour,
although the aortic diameter is usually preserved. It can
sometimes be very difficult to differentiate subadventitial
traumatic aortic rupture from aortic dissection. Echocar­
diographic findings supporting subadventitial traumatic
aortic rupture include asymmetrical contour at the level
of aortic isthmus, thick and highly mobile medial flap,
absence of tear, presence of mediastinal hematoma, simi­

lar blood flow velocities on both sides of the flap, and
mosaic color Doppler flow surrounding the disruption.
In contrast, TEE findings supporting aortic dissection
include symmetrical enlargement of the aortic contour,
thin and less mobile intimal flap, entry and exit tears, no
mediastinal hematoma, thrombus formation in the false
lumen, different blood flow velocities in both the true
and false lumens, and finally, absence of mosaic color
Doppler flow mapping on both sides of the intimal flap.
Traumatic aortic intimal tears appear echocardio­
graphically as thin, mobile intraluminal appendages of
aortic wall that are located in the region of the aortic
isthmus. Since these lesions are small and superficial,
the contour and diameter are unaffected, and color­
flow mapping does not demonstrate turbulence. Medi­
astinal hematomas have three characteristic TEE find­
ings: increasing space between the probe and the wall of
the aorta, double contour aortic wall, and a distinct
echogenic space between the bright aortic wall and the
visceral pleura. This space is typically seen in the far
field adjacent to the posterolateral aortic wall.
Associated lesions with traumatic aortic injury have
been reported by Goarin and colleagues.70 These consist of
pulmonary contusion, left pleural effusion, rib fractures,
diaphragmatic rupture, mediastinal hematoma, hemoperi­
cardium, myocardial contusion, valvular lesions, and
hypovolemia. Some of these lesions become apparent
much later after the initial injury; hence, a follow-up TEE
examination is mandatory.

ENDOVASCUL AR STENTING
In the early 1 990s, the use of endovascular stems to treat
aortic pathologies was introduced. Since then, stents have
become an increasingly utilized alternative to conventional


ECHOCARDIOGRAPHY FOR AORTIC SU RGERY

aortic surgery.71•72 There was initial skepticism for their
use in the thoracic aorta due to concerns about their
durability in this region with higher hemodynamic stress.
However, as experience grew with their use in the tho­
racic aorta, endovascular stenting became a widely
adopted practice and has been routinely used since the
early 2000s for the treatment of complex aortic diseases.
On March 23, 2005, the U.S. Food and Drug
Administration (FDA) approved the Gore TAG thoracic
endoprosthesis. Since then, two other thoracic stent
graft systems have received approval: the Medtronic
Talent (Medtronic Vascular, Santa Rosa, CA, USA) and
the Zenith TX-2 (Cook Medical Inc, Bloomington, IN,
USA) . Currently, the only FDA-approved indication for
the use of these devices is for the treatment of thoracic
aortic aneurysmal disease. However, endovascular stents
are now being successfully used for other aortic pathol­
ogy such as acute and chronic dissection, transection,
and aorto-bronchial fistulae. The early results have been
very promising, and long-term data on durability are
awaited.73 In aneurysmal disease, the goal of the stent is
to exclude the aneurysmal sac so that further dilation

and disease progression can be prevented. In aortic dis­
section, the goal of the sent is to exclude the intimal tear,
thus preventing its evolution. During an EVAR proce­
dure, TEE is extremely valuable and can be used to
verifY pathology such as the site of the intimal tear, to
identifY the true and false lumen, to guide stent placement,
to detect endoleaks, and to assess cardiac performance. 74
It can also be used to take measurements of the aorta
and the aortic lesion, document side branch patency;
and detect static or dynamic obstruction. An added ben­
efit ofTEE is the noninvasive visualization and direction
of guidewires and catheters on short- and long-axis
views of the aorta, thus reducing the need for nephro­
toxic contrast agents. A guidewire appears as a linear
echo-dense intraluminal structure. TEE is also an excel­
lent hemodynamic monitor, especially during inflation
of the balloon to unfold the stent. Similar to cross­
clamping of the aorta, inflation of the balloon can cause
significant aortic occlusion and subsequent strain on
the heart, and result in regional or global myocardial
ischemia. Newer endoaortic balloons, however, incorpo­
rate a nonocclusive design that permits partial flow,
thereby reducing the extent of myocardial strain. How­
ever, TEE use is limited by the poor visualization of the
distal ascending aorta and proximal arch, and by the
need for general anesthesia. There is also the potential
interference of the TEE probe with fluoroscopy during
procedures in the aortic arch.
Although an off-label indication, the use of EVAR
for dissection deserves special consideration. First, siz­

ing of the endograft is based solely on the diameter of
the aorta at the proximal landing zone, since the distal
zone will include both the true and false lumens. This

I

3 79

is in contrast to aneurysms where both proximal and
distal aortic diameters must be considered. Second, it
is critical for the guidewire of the endograft delivery
system to be within the true lumen. This can be easily
facilitated with TEE, which is superior to angiography
in this regard. Finally, TEE can be useful in identifY­
ing distal fenestrations between the true and false
lumens, which may determine the number of endo­
grafts to be used.
Another emerging indication for EVAR is trau­
matic aortic transections. These patients are typically
young, have multiple inj uries, and are critically ill.
They are also hyperdynamic, which makes endograft
deployment challenging. TEE imaging can also be
difficult in a setting where there may be multiple sur­
gical specialties involved, and facial or spinal inj uries
may limit the opportunities for esophageal imaging.
A distinct feature from an echocardiographic perspec­
tive is that the left subclavian artery is almost always
covered, and loss of flow on CFD imaging should be
expected.
An endoleak is a common complication following

endovascular repair of the aorta. It is characterized by
persistent blood flow within the aneurysmal sac or adja­
cent vascular segment being treated by the stent, and
may occur in 20% of patients.75 Endoleaks are charac­
terized into four types based on location (Table 1 6-3)76
and can also be classified on the basis of time of occur­
rence: primary endoleaks are detected within the first
30 days postoperatively while secondary endoleaks
occur after 30 days. Endoleaks can also be detected by
TEE, which has been demonstrated to be more sensitive
than angiography (Figure 1 6-8) .77•78 A limitation of

Table 1 6-3. C l a ssification of e n d o l ea ks.

Type

II

Ill

IV

Description
Attachment site lea k
A Proximal leak
B Dista l leak
C I l iac occluder
Branch leaks
A To and fro simple flow from branch vessel
i nto aneurysmal sac

B Complex flow through two or more branch
vessels i nto the aneurysmal sac
Graft defect
A Mid graft hole
B J u nctional leak or g raft disconnection
C Other mecha nisms, eg, fai l u re from suture
holes
Graft wa l l porosity


380

C H A PTER 1 6

FIGURE 1 6-8. Type I B (distal) endoleak.The stent (S) and aneurysmal sac (A) a re shown i n two-dimensional (left
panel) and color-flow (right panel) imaging. A small jet (arrow) is seen entering the aneurysmal sac from the d ista l

portion of the stent.

angiography is that it relies on a fixed volume of
contrast to circulate within the endoleak. Therefore,
smaller leaks may be overlooked because the volume of
contrast within the leak may not be detectable by fluo­
roscopy, or the imaging angle may not be aligned to
detect the endoleak. Most endoleaks can be detected
using CFD in the region of the aneurysmal sac. How­
ever, endoleaks that are in the far field may be obscured
by echo-dense endograft material. Additionally, the
color scale for CFD may need to be reduced in order to
visualize low-flow leaks. Another echocardiographic

sign of an endoleak is the development of spontaneous
echo contrast (SEC, or "smoke") within the aneurysmal
sac following the deployment of the stent.79 The sud­
den development of SEC in a previously quiescent
aneurysmal sac should alert the echocardiographer to the
potential presence of an endoleak. Contrast that swirls or
moves around the sac may indicate an endoleak, while
static contrast indicates no movement or flow within the
sac, suggesting the absence of any endoleak. Detecting
endoleaks intraoperatively also provides the opportunity
for immediate corrective interventions.

AORTIC COARCTATION
Coarctation of the aorta is a congenital narrowing of the
aorta at the level of the aortic isthmus. Described more
completely in Chapter 1 8, a coarctation can be preductal,
ductal, or postductal, and can vary in length. It is com­
monly associated with other cardiac abnormalities includ­
ing bicuspid aortic valve and patent ductus arteriosus.
The classical presentation is arterial hypertension in the

right arm with normal to low blood pressure in the
lower extremities. TEE findings include narrowing of
the aorta distal to the subclavian artery and turbulent
blood flow on CFD. The anatomical position of this
lesion makes transthoracic echocardiography the imag­
ing modality of choice. The coarctation is best visualized
with the transducer at the suprasternal notch.

SUMMARY

Transesophageal echocardiography is invaluable for
perioperative imaging of the aorta. The anatomical
j uxtaposition of the aorta and esophagus makes TEE
an ideal imaging tool, especially for thoracic aortic
pathology. From complex lesions in the ascending
aorta to endovascular stenting, TEE can provide valu­
able information to the intraoperative echocardiogra­
pher, including lesion identification, measurement of
aortic dimensions, quantification of associated abnor­
malities like aortic incompetence, and detection of
complications such as endoleaks.

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atheromatous disease diagnosed by transesophageal echocar­
diography predicts stroke and other outcomes associated with

70. Goarin JP, Catoire P, Jacquens Y, et al. Use of transesophageal
echocardiography for diagnosis of traumatic aortic injury.
Chest. 1 997; 1 1 2 ( 1 ) : 7 1 -80.

,


ECHOCARDIOGRAPHY FOR AORTIC SU RGERY

7 1 . Dake MD, Miller DC, Semba CP, Mitchell RS , Walker PJ,
Liddell RP. Transluminal placement of endovascular stem-grafts
for the treatment of descending thoracic aortic aneurysms.
N Eng!] Med. 1 994;33 1 (26) : 1 729- 1 734.
72. Parodi JC, Palmaz JC, Barone HD. Transfemoral intraluminal
graft implantation for abdominal aortic aneurysms. Ann Varc
Surg. 1 99 1 ; 5 (6) :49 1 -499.
73. Verhoye JP, de Latour B, Heautot JF, et al. Mid-term results of
endovascular treatment for descending thoracic aorta diseases in
high-surgical risk patients. Ann Varc Surg. 2006;20(6) : 7 1 4-722.
74. Swaminathan M, Lineberger CK, McCann RL, Mathew JP.
The importance of intraoperative transesophageal echocardiog­
raphy in endovascular repair of thoracic aortic aneurysms.
Anesth Analg. 2003;97(6) : 1 566- 1 572.

75. van Marrewijk C, Burh J , Harris PL, Norgren L, Nevelsteen A,
Wyatt MG. Significance of endoleaks after endovascular repair
of abdominal aortic aneurysms: The EUROSTAR experience.
J Varc Surg. 2002;35 (3):46 1 -473.

76. Veith FJ, Baum RA, Ohki T, et al. Nature and significance of
endoleaks and endotension: summary of opinions expressed at
an international conference. J Varc Surg. 2002;35 (5) : 1 029- 1035.
77. Fattori R, Caldarera I, Rapezzi C, et al. Primary endoleakage
in endovascular treatment of the thoracic aorta: importance
of intraoperative transesophageal echocardiography. J Thorac
Cardiovarc Surg. 2000; 1 20 (3) :490-495 .
7 8 . Rapezzi C , Rocchi G, Fattori R , e t al. Usefulness o f trans­
esophageal echocardiographic monitoring to improve the out­
come of stent-graft treatment of thoracic aortic aneurysms. Am
J Cardiol. 200 1 ; 87(3) : 3 1 5-3 1 9 .
7 9 . Swaminathan M, Mackensen GB, Podgoreanu MY, McCann
RL, Mathew JP, Hugbes GC. Spontaneous echocardiographic
contrast indicating successful endoleak management. Anesth
Analg. 2007; 1 04(5) : 1 037- 1 039.

REVIEW QUESTIONS
Select the one best answer for each of the following
questions.
1 . Which of the following is TRUE regarding the
anatomy of the ascending thoracic aorta?
a. It travels anterior to the main pulmonary artery.
b. It travels in a posterior, cranial, and rightward
direction over the right pulmonary artery.
c. It travels in an anterior, cranial, and rightward
direction over the right pulmonary artery.
d. It travels in a posterior, cranial, and rightward
direction over the left pulmonary artery.
2. Which of the following anatomical segments of the
aorta includes the aortic isthmus?

a. Ascending thoracic aorta
b. Aortic arch
c. Mid-descending thoracic aorta
d. Distal descending thoracic aorta
3. Which of the following is TRUE regarding the
descending thoracic aorta?

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383

a. It starts distal to the right side of the body ofT4.
b. It runs downward from the side of T4 to the
anterior side ofT1 1 .
c. It runs vertically along the vertebral column
towards the esophageal hiatus.
d. It starts anterior to the esophagus.
4. The artery of Adamkiewicz most commonly
originates from which of the following thoracic
levels?
a. T2 to TS
b. T4 to T9
c. T6 to T l O
d . T 9 to T 1 2
5 . Which o f the following techniques i s most likely to
result in optimal visualization of a normal descend­
ing thoracic aorta?
a. Using an imaging depth of 1 2 em to optimize
measurements
b. The use of a low transducer frequency to improve

spatial resolution
c. Concurrent use of color-flow Doppler to
improve temporal resolution
d. Leftward rotation of the probe at the level of
the left atrium
6. Which of the following is the optimal technique
for evaluating the anatomy of the ascending aorta?
a. The ME aortic valve short-axis view at 30° to 60°
b. Using tissue Doppler with high frame rates
c. Epiaortic imaging with a high-frequency
transducer
d. Using color M-mode to improve temporal
resolution
7. Which of the following are ideal for imaging the
proximal aortic arch?
a. The upper esophageal short-axis view using
high frequencies.
b. The midesophageal short-axis view at the level
of the main pulmonary trunk.
c. An upper esophageal long-axis view.
d. Scanning the arch in a short-axis plane with
rotation of the shaft from left to right may dis­
play the arch vessels.

8. A 54-year-old male is admitted with chest pain and
suspected Type A dissection. He was imaged in an
outside hospital emergency room but the imaging
details are unavailable. He remains symptomatic
with ST changes on his ECG in the LAD territory,
and is scheduled for emergent surgery. The sur­

geon requests a TEE examination immediately after
induction of anesthesia. Which of the following


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C H A PTER 1 6

views is likely to confum the diagnosis of Type A dis­
section AND associated wall motion abnormalities?
a. Midesophageal RV inflow-outflow
b. Transgastric mid-short axis
c. Midesophageal long axis
d. Upper esophageal arch short axis

9. In the patient in question 8, the echocardiographer

suspects a possible intimal flap in the descending
aorta. Which of the following techniques will most
likely help establish the presence of a dissection in
the descending aorta?
a. Use of color-flow Doppler to determine differ­
ential flow velocities in true and false lumens
b. Use of tissue Doppler to image aortic tissue
velocity throughout the cardiac cycle
c. Use of M-mode to determine differential flow
in the true and false lumens
d. Use of pulsed-wave Doppler to determine holo­
diastolic flow in the true lumen

1 0 . Which of the following classifications accurately
describes an aortic dissection involving only the
ascending aorta?
a. DeBakey type I
b. Stanford type B
c. European System class N
d. DeBakey type II

1 1 . The development of the Stanford and European clas­

sification systems for aortic dissections was primarily
based on which of the following clinical needs?
a. Different lesions have distinct management
strategies.
b. Different imaging modalities have distinct diag­
nostic sensitivities for different lesions.
c. The identification of true and false lumens will
impact management.
d. Complications of different types need to be
managed appropriately.

1 2 . Which of the following accurately describes the appro­
priate type of thoracoabdominal aortic aneurysm that
involves the distal half or less of the descending tho­
racic aorta and substantial segments of the abdominal
aorta according to Crawford's classification system?
a. Type I
b. Type II
c. Type III
d. Type IV

1 3 . Which of the following factors is most likely
involved in the etiology of aortic dissections?
a. Connective tissue diseases
b. Cystic medial necrosis

c. Syphilitic infections
d. Trauma
14. Which of the following best describes the pathol­
ogy of an aortic dissection?
a. Formation of an intimal tear is frequently a late
phenomenon.
b. Blood flow between the tunica media and
tunica adventia.
c. Intramural hematoma cannot progress to dis­
section or rupture.
d. Intramural hematoma may account for up to
30% of early aortic dissections.

1 5 . A 62-year-old female presents with a saccular

aneurysm in the descending thoracic aorta 4 em
below the aortic origin of the subclavian artery. An
endovascular repair is planned. Standard monitor­
ing is employed, including left radial arterial pres­
sure. Immediately after graft deployment and
endo-balloon inflation, severe systemic hypoten­
sion is observed. Which of the following is most
likely to explain this clinical finding?
a. Inadvertent stent coverage of the left subclavian

artery
b. Myocardial strain due to balloon occlusion of
the aorta
c. Coronary ischemia following balloon deflation
d. Bleeding due to possible rupture from balloon
overinflation

1 6 . A 48-year-old male is admitted with chest pain and
suspected aortic dissection. He is scheduled for emer­
gent surgery since his CT scan revealed a Type A
dissection. However, in the operating room, the
echocardiographer does not observe a dissection flap in
the ascending aorta with TEE. Although a sternotomy
has been performed, the aorta has not yet been manip­
ulated. Which of the following is the approach most
likely to establish the diagnosis of a Type A dissection?
a. Angiography in the operating room with contrast.
b. Color-flow Doppler with TEE in the ascending
aorta.
c. Comprehensive epiaortic scan with a high-fre­
quency tranducer.
d. Defer surg�ry pending repeat magnetic reso­
.
nance tmagmg.

1 7. In aortic dissection, which of the following aortic

side branches can be reliably assessed for malperfu­
sion defects using TEE?
a. Coronary arteries

b. Spinal cord arteries
c. Renal arteries
d. Mesenteric arteries


ECHOCARDIOGRAPHY FOR AORTIC SU RGERY

1 8 . A patient presents to the operating room for an
emergent repair of a Type A dissection. History is
significant for gradually worsening delirium and
confusion in addition to chest and back pain, and
shortness of breath. Prior to induction, the sys­
temic arterial pressure is 92/66 mm Hg, central
venous pressure is 2 1 mm Hg, and the heart rate is
1 1 0/ min. Which of the following are most likely to
be seen during intraoperative imaging?
a. Pericardia! effusion, wall motion abnormalities,
and ascending aortic atheroma
b. Pleural effusion, wall motion abnormalities,
and ascending aortic atheroma
c. Pericardia! effusion, wall motion abnormalities,
and carotid dissection
d. Pleural effusion, ascending aortic atheroma, and
carotid dissection
1 9 . Which of the following imaging modalities may
reliably be used to distinguish between the true
and false lumen in aortic dissections?
a. Tissue velocity and strain of aortic walls on
either side of an intimal flap
b. Flow velocity aliasing seen in the false lumen on

color-flow Doppler
c. Movement of the intimal flap towards the true
lumen in systole on 2D imaging
d. Higher-velocity flow in the true lumen on color
M-mode imaging
20. During intraoperative TEE imaging in a patient
undergoing repair of a Type A dissection with
extension into the descending aorta up to the celiac
vessels, the echocardiographer notes fluttering of
the anterior mitral leaflet in diastole. Which of the
following is most likely to suggest severe aortic
regurgitation in this patient?
a. Diastolic mitral regurgitation on color-flow
Doppler (CFD)
b. Systolic turbulence on CFD in the LV outflow tract
c. Holodiastolic flow in one lumen in the
descending aorta
d. Dissection flap in the ascending aortic short­
axiS vtew
2 1 . An intimal flap of a Type A aortic dissection is
most likely to be mistaken for a mirror image arti­
fact of which of the following structures?
a. Pulmonary artery catheter
b. Intra-aortic balloon pump catheter
c. Pacing catheters in the superior vena cava
d. Pericardia! reflection of the oblique sinus
22. Which of the following is the most common loca­
tion for an intimal tear?

a.

b.
c.
d.

I

385

Sinuses ofValsalva
Distal ascending aorta
Ligamentum arteriosum
Sinotubular junction

23. Which of the following attributes of an aortic
atheroma are particularly significant for adverse
outcome and should be reported during intraoper­
ative imaging?
a. Irregularities on the plaque surface
b. Gray-scale density of the atheroma
c. Mobility of the atheromatous plaque
d. On which wall the lesion is located
24. While several grading systems have been advo­
cated and used in practice, they use variable meas­
ures of atheroma severity. Which of the following
attributes is common to all atheroma classification
systems?
a. Thickness or height of the atheroma
b. Gray-scale density or calcification
c. Ulceration of plaque surface
d. Plaque area as a measure of burden

25. Intraoperative TEE is particularly suited for detect­
ing atheromatous lesions in which of the following
areas of the aorta?
a. Distal ascending
b. Proximal arch
c. Mid ascending
d. Proximal descending
26. Epiaortic scanning is particularly suited for detect­
ing atheromatous lesions in which of the following
areas of the aorta?
a. Mid descending
b. Proximal ascending
c. Distal arch
d. Proximal descending
27. According to the European Society, an aortic dis­
section caused by an intramural hematoma is what
class of aortic lesion?
a. Class I
b. Class II
c. Class III
d. Class N
28. Pleural effusions are commonly the result of tran­
sudation of fluid in which of the following aortic
lesions?
a. Type II dissection
b. Intramural hematoma
c. Penetrating ulcer
d. Type B dissection

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C H A PTER 1 6

29. During endovascular repair, measurement of the
aortic diameter is more important in the proximal
landing zone than the distal landing zone in which
of the following conditions?
a. Saccular aneurysm
b. Penetrating ulcer
c. Aortic transaction
d. Type B dissection
30. Which of the following is the optimal view to
assess for the presence of a left pleural effusion?
a. Midesophageal long-axis view
b. Deep transgastric long-axis view
c. Midesophageal descending aortic short-axis view
d. Midesophageal ascending aorta short-axis view
3 1 . Which of the following is an indication for surgical
therapy of an aortic aneurysm?
a. Symptomatic patient
b. A fusiform aneurysm of 5.0 em
c. Saccular aneurysm less than 1 . 5 em
d. A thoracic aortic diameter of 3 . 5 em
32. During endovascular repair, TEE is most likely to
be useful for which of the following?
a. Measurement of distal ascending aortic diameter
b. Flow in the innominate artery branch of the
aorta
c. Type 1 endoleak in the proximal descending

aorta
d. Graft sizing in the distal landing zone for dis­
sections
33. A 74-year-old man presents for endovascular repair
of an aortic aneurysm that extends from 1 em
below the origin of the left subclavian artery to the
level of the diaphragm. The surgeon plans to cover
the subclavian artery due to a narrow landing zone.
After endograft employment, the anesthesiologist
notes that the cerebral oxygen saturation is low on
the left side and the hi-spectral index is below that
expected. Which of the following is the most likely
explanation for the sudden developments of these
neuromonitoring values?
a. Expected coverage of the left subclavian
b. Dissection of the left carotid from endografting
c. Inadvertent coverage of the left common
carotid
d. Air embolism from endoballoon rupture
34. A patient undergoes endografting for repair of a
thoracoabdorninal aortic aneurysm. During his
endograft deployment, the surgeon suspected that
the patient may develop a future type II endoleak.

Which of the following imaging modalities is ideal
for detecting this type of endoleak?
a. Transesophageal echo
b. Cine-angiography
c. Intravascular ultrasound
d. Spiral CT scan

3 5 . Which of the following is most likely to be mis­
taken for a Type B dissection on intraoperative
imaging with TEE?
a. Left pleural effusion
b. Mobile atheroma
c. Mirror image artifact
d. Pulmonary artery catheter
36. Which of the following echocardiographic findings
is considered a classic sign of an aortic dissection?
a. Penetrating ulcer
b. Intramural hematoma
c. An intimal flap
d. Entry and exit tear
37. Which of the following echocardiographic findings
indicates an endoleak on TEE?
a. Static echo contrast in the aneurysmal sac
b. Turbulent flow in the sac on color Doppler
c. Flow within the dissection true lumen
d. Pulsatile movement of the endograft
38. Which of the following lesions is most often pres­
ent in the descending aorta, does not extend longi­
tudinally, is associated with atherosclerotic disease,
and may lead to aortic rupture?
a. Fusiform aneurysm
b. Type B dissection
c. Ulcerating plaque
d. Intramural hematoma
39. Which of the following lesions is most often associ­
ated with subadvential traumatic aortic disruption?
a. Esophageal rupture

b. Right pleural effusion
c. Clavicular fracture
d. Mediastinal hematoma
40. Which of the following echocardiographic findings
is most likely in a patient admitted to the emer­
gency room following a motor vehicle accident
with multiple injuries?
a. Thick intimal tear in the aortic arch
b. Wall motion abnormalities
c. Sinotubular calcification
d. Aortic root aneurysm


Tra n seso p h a g ea l Echoca rd i og ra p hy
fo r H ea rt Fa i l u re S u rg e ry
Susan M. Martinelli, Joseph G. Rogers, and Carmelo A. Milano

The epidemic of heart failure is a worldwide problem
that is anticipated to increase with both an aging pop­
ulation and the improved survival from cardiac compli­
cations producing left ventricular systolic dysfunction
(e.g. myocardial infarction) . Increasingly, these patients
who survive a serious cardiac injury but have persistent
ventricular dysfunction precluding normal end-organ
function experience a poor quality oflife and high rates
of morbidity and mortality. At the age of 40, the life­
time risk of developing heart failure is 20%, and the
1 -year heart failure mortality rate is 20%. 1 The num­
ber of hospitalizations for heart failure has tripled
between the 1 970s and 2004, and contemporary data

indicate that heart failure was the primary or second­
ary cause of 3 . 8 million annual admissions in the
United States.2 It is estimated that the direct and indi­
rect costs of heart failure in the United States will
exceed $37 billion in 2009, highlighting the economic
importance of this disease. 1
While most heart failure patients are managed med­
ically, surgical options for refractory heart failure
include orthotopic heart transplantation and mechani­
cal circulatory support. Advances in donor and recipient
selection, organ procurement, and immunosuppressant
therapy have led to an increase in the survival of grafted
organs. Transplant surgery is currently considered the
treatment of choice for end-stage heart, lung, and
liver diseases, but the predominant limiting factor is a
shortage of donors. Mechanical circulatory support
has therefore emerged as a valuable and viable adj unct
to transplantation in the management of heart failure
patients.
Echocardiography plays an essential role in the donor
organ selection process and preoperative screening, peri­
operative management, and post-transplant follow-up
of recipients. Similarly, perioperative transesophageal
echocardiography (TEE) provides invaluable anatomic
and functional information in patients receiving circula­
tory support devices, which influence not only anes­
thetic management but also surgical decision making.
The following text will first describe the role of TEE in
heart transplantation, followed by a discussion of its

value in the implantation of mechanical circulatory
support devices.

HEART TRANSPL ANTATION
The application ofTEE as a diagnostic and monitoring
modality in heart transplant surgery can be divided into
five categories:
1 . Cardiac donor screening
2. Intraoperative monitoring in the pretransplant period
3. Intraoperative evaluation of cardiac allograft function
and surgical anastomoses in the immediate posmans­
plantation period
4. Management of early postoperative hemodynamic
abnormalities in the intensive care unit
5. Postoperative follow-up studies of cardiac allograft
function
Role of T E E in Cardiac Donor Screening

As a result of the shortage of available donor hearts,
many institutions are now liberalizing their acceptance
criteria to include higher-risk (marginal) donor hearts.3
Table 1 7-1 presents the conventional cardiac contraindi­
cations to the use of a donor heart. Despite the potential
risk for transmitting atherosclerotic, hypertensive, and
valvular heart diseases, organs from older donors are
increasingly being used. This aggressive approach has
proved particularly successful when matching for higher­
risk recipients (alternate recipient list) with a greater
short-term mortality risk or with significant comorbid
factors.4

Echocardiography plays an important role in the
effort to improve the yield of donor evaluation.5 By rul­
ing out donors with structural abnormalities, severe
ventricular dysfunction, or significant wall motion
abnormalities (WMAs) , the need for costly and time­
consuming cardiac catheterization can be circumvented.
In potential donors on ventilatory support, TEE has
been shown to be particularly useful in providing


388

I

C H A PTER 1 7

Table 7 7- 7 . Contra i n d icatio ns to the U s e of a
Potential D o n o r H ea rt.

Donor hea rts with preexisting heart disease: coronary
a rtery disease, va lvular hea rt d isease, or significant
congenital anomal ies
Hemodynamic i n stabil ity req u i ring excessive i notropic
suppo rt
Ca rdiac contusion
Severe wa l l motion abnormal ities on echoca rdiogram
Persistent left ventricular dysfu nction (ejection fraction
<0.4) despite optim ization of preload, afterload, and
inotropic support
Severe left ventricular hypertrophy on inspection of the

hea rt
I ntracta ble ventricular or supraventricular a rrhythmias
Brain death as a result of card iac a rrest
Prolonged or repeated episodes of cardiopul monary
resuscitation

ventricular dysfunction after traumatic brain injury
may be global or regional. For both types of brain
injury, there is a poor correlation between the distribu­
tion of echocardiographic dysfunction and actual histo­
logic evidence of myocardial injury. Some studies have
suggested that WMA and global function improve
shortly after heart transplantation, but a recent multi­
institutional study identified WMA on the donor
echocardiogram as a powerful independent predictor of
early graft failure.9 WMA on the donor echocardiogram
may be particularly important when associated with a
donor age older than 40 years and an ischemic time
longer than 4 hours.
The lowest fractional area change in a donor heart
permitting safe transplantation is unknown, but it has
been suggested that a fractional area change greater
than 35%, in the absence of other cardiac abnormali­
ties, could be used as a guide. 8
I ntraoperative Mon itoring in the
Pretra nsplant Period

consistent high-quality imaging when transthoracic
echocardiography (TIE) has proved inadequate.
An initial echocardiogram should not be obtained

before adequate hemodynamic and metabolic resusci­
tation. In particular, volume status, acidosis, hypox­
emia, hypercarbia, and anemia should be corrected, and
inotropic support should be weaned to a minimum
compatible with adequate blood pressure and cardiac
output (CO) . The goals of the echocardiogram are to
rule out structural abnormalities and assess regional and
global functions. It is unclear if donor hearts with left
ventricular (LV) hypertrophy, defined as a wall thicker
than 1 1 mm in the absence of underfllling of the ven­
tricle (pseudohypertrophy) , can safely be used for trans­
plantation. One study shows that LV hypertrophy
(LVH) may increase the incidence of early graft failure, 6
but a more recent study demonstrated that hearts with
mild ( 1 2 to 1 3 mm) or moderate ( 1 3 to 1 7 mm) LVH
do not increase morbidity. 3 Most valvular and congeni­
tal abnormalities preclude transplantation, with the
possible exception of mild lesions such as mitral valve
prolapse in the absence of significant regurgitation, a
normal functioning bicuspid aortic valve, or an easily
repairable secundum-type atrial septal defect.
Segmental WMAs in donor hearts may be the result
of coronary artery disease, myocardial contusion, or
ventricular dysfunction after brain inj ury. Contused
myocardial tissue resembles infarcted myocardial tissue
histologically and functionally? The pattern of ventric­
ular dysfunction after spontaneous intracranial hemor­
rhage is usually se�mental and often spares the apex of
the left ventricle. This pattern correlates with the
sympathetic innervation of the ventricle. In contrast,

Idiopathic and ischemic cardiomyopathies are the two
most common causes of cardiac failure in the transplant
recipient. Regardless of the cause of failure, global car­
diac dilatation is a common feature and the term
dilated cardiomyopathy has been applied to this end­
stage condition. These patients have fixed, low stroke
volumes and are very dependent on an adequate pre­
load. Further, even mild increases in afterload may
result in a marked reduction in stroke volume. Patients
in cardiac failure compensate for their low CO by an
increase in sympathetic activity, which leads to general­
ized vasoconstriction and to sodium and water reten­
tion. This delicate balance among preload, contractility,
and afterload can be dramatically disturbed after the
induction of general anesthesia. TEE is therefore ideally
suited to rapidly evaluate and guide intraoperative man­
agement in these patients. Several factors commonly
seen in recipients, including diastolic dysfunction,
regurgitant valvular lesions, and positive pressure venti­
lation, result in a poor correlation between measured
filling pressures and LV volumes. Thus, optimization of
LV filling and inotropic support can be more readily
and rapidly achieved under TEE guidance. Right ven­
tricular (RV) size and function also should be assessed
in these patients. The presence of RV hypertrophy is
suggestive of long-standing pulmonary hypertension,
which may lead to acute RV dysfunction in the trans­
planted heart.
TEE is similarly sensitive in detecting intracardiac

thrombi, with the possible exception of an apical
thrombus. Prethrombotic sluggish blood flow is char­
acterized echocardiographically as spontaneous con­
trast or "smoke." Patients with dilated cardiomyopathy,


TRANSESOP HAGEAL ECHOCARDIOGRAPHY FOR H EART FAI LU RE SU RGERY

especially in the presence of spontaneous echo contrast,
have a high incidence of thrombus formation in the
apex of the left ventricle. The left atrial (LA) appendage
also should be inspected for possible thrombi, particu­
larly in patients with atrial fibrillation. When thrombi
are present in the left heart, manipulation of the heart
before cardiopulmonary bypass (CPB) should proceed
with great caution in an effort to avoid systemic throm­
boembolism. Other sources of embolism during the
pretransplant period include atheromatous plaque from
the ascending aorta during aortic cannulation or air
entrainment during the explantation of ventricular
assist devices. As in all CPB cases, the aorta (ascending
aorta, arch, and descending aorta) should be examined
for atherosclerotic plaque before aortic cannulation.
TEE is extremely sensitive in the detection of intravas­
cular air and early detection and intervention may
potentially limit this complication.
It is common practice to place a pulmonary artery
(PA) catheter into the PA only after CPB because it is
often difficult to pass these catheters through large
dilated ventricles, incompetent tricuspid valves, and in

low CO states. PA catheter placement is also more prone
to induce arrhythmias. TEE therefore can be used to
determine CO and PA pressures during the pre-CPB
period (see Chapter 4) .
I ntraoperative Mon itoring in the
Posttra nsplantation Period

TEE imaging of the heart during and after weaning
from CPB provides invaluable information with impor­
tant diagnostic and prognostic implications. Before
weaning from CPB, TEE is used to detect retained air
and to assist venting and de-airing maneuvers. The most
common sites of air retention are the right and left
upper pulmonary veins, the LV apex, the left atrium,
and the coronary sinus. The right coronary artery is
commonly affected by air embolism because of its more
superior location in the ascending aorta, resulting in a
hypocontractile dilated right ventricle and ST-segment
changes in the inferior electrocardiographic leads. After
separation from CPB, a detailed examination of the
transplanted heart should include the elements listed in
Table 1 7-2.
The function of the newly transplanted heart
depends on many factors: baseline function before
brain death, degree of myocyte damage before and dur­
ing harvesting, amount of donor inotropic support,
ischemic time, myocardial protection during the ischemic
interval, reperfusion injury, cardiac denervation, donor­
recipient size mismatch, and degree of pulmonary
hypertension in the recipient. To accurately assess car­

diac allograft anatomy and physiology, the echocardiog­
rapher needs to understand the surgical procedure and

I

389

Table 1 7-2. I ntraoperative Exa m i nation of the
Tra n s p l a nted H e a rt.

Assessment of:
Left ventricular reg ional and global systolic fu nction
Left ventricular d iastolic fu nction
Right ventricu l a r fu nction
Atrioventricular valves
Atria and atrial a nastomoses
Pulmonary a rterial a nastomosis
Pulmonary venous anastomoses

appreciate the changes that normally occur in the trans­
planted heart.
The standard or biatrial technique, originally
described by Lower and Shumway, was the primary
method for nearly 30 years. 1 0 However, more trans­
plantation centers are now using the bicaval anasto­
motic technique as the method of choice, except in
infants and small children. The advantages of the
bicaval technique include preserved geometry and
function of the atria, improved CO, and less disrup­
tion in the geometry of the atrioventricular valves,

resulting in reduced valvular regurgitation, fewer con­
duction abnormalities, less thrombus formation in the
left atrium, and decreased perioperative mortality. 1 1 In
the standard technique, most of the native atrial walls
and the interatrial septum are left in situ, leaving the
inferior vena cava (IVC) , superior vena cava, and pul­
monary venous inflow tracts undisturbed. In the
donor heart, an LA cuff is created by incising through
the pulmonary vein orifices, whereas the right atrial
(RA) cuff is created by incising through the inferior
vena caval orifice and extending the incision up
toward the base of the RA appendage. When the
bicaval technique is performed, most of the native
atrial tissue is excised, thereby creating superior vena
cava and IVC cuffs for end-to-end anastomoses with
the donor vena cavae. Divisions and end-to-end anas­
tomoses of the great vessels are the same for both
techniques.
Intraoperative TEE assessment of allograft LV sys­
tolic function early after separation from CPB has been
shown to better predict early requirements for inotropic
and mechanical support than routinely measured
hemodynamic variables, particularly when ischemic
times are prolonged. 1 2 In general, allograft LV systolic
function after CPB is expected to be normal, and
impaired LV systolic function at this stage, usually the
result of ischemic injury or early acute rejection, is
often transient. It is important to document any intra­
operative regional WMAs because coronary atheroscle­
rosis and myocardial infarction, often silent, are major

3 90

C H A PTER 1 7

Table 7 7-3. C h a ra cteristic Two- D i m e n s i o n a l
Ech oca rd i o g ra p h i c C h a n ges i n t h e Left Ve ntri c l e
After H e a rt Tra n s p l a nt.

Increased wa l l thickness, especia l ly i nferolateral and septa l
wa l l s
Paradoxical or flat i nterventricular septa l motion and
decreased septa l systolic thicken ing
Clockwise rotation and med ial shift of the left ventricle
within the mediast i n u m, necessitating nonsta ndard
transesophagea l echocardiographic transducer
positions and angles
Small postoperative pericardia! effusions

causes of morbidity and mortality after heart transplant
surgery.
There are several echocardiographic findings that
could be considered abnormal in the general popula­
tion but are characteristic in the allograft left ventricle.
These are listed in Table 1 7-3 . Increases in LV wall
thickness and LV mass are thought to represent myocar­
dial edema resulting from manipulation and transport
of the heart. Because the donor heart is typically smaller
than the original dilated failing heart, it tends to be

positioned more medially in the mediastinum and
tends to be rotated clockwise. This could result in diffi­
culties in obtaining the standard tomographic planes,
and nonstandard TEE probe positions and angles may
have to be used.
Diastolic compliance is often decreased in the first few
�ys or :-veeks after cardiac transplant, but typically
rmproves m the first year.4 This is most likely the result of
ischemia or reperfusion injury, a smaller donor heart in a
larger recipient, or a larger heart implanted into a restricted
pericardial space. Unfortunately, Doppler echocardio­
graphic assessment of LV diastolic function is complicated
by a variety of factors, outlined in Table 1 7-4. When rem­
nant atrial tissues retain mechanical activity, atrial con­
tractions become asynchronous, resulting in beat-to-beat

Table 7 7-4. Factors Co m p l i cati n g D o p p l e r
Ech oca rd i o g ra p h i c Left Ventri c u l a r D i a sto l i c
F u n ction Asses s m e n t After H e a rt Tra n s p l a ntati o n .

Asynchronous atria l contractions may result i n beat-to-beat
variations in transm itral flow
Left atrial dysfu nction also may result in abnormal trans­
m itral and pulmonary venous flow patterns
Reci pient P waves and va rious pacing modes compl icate
measurements

variations in transmitral inflow velocities. Atrial dysfunc­
_
tion

can also result in abnormal transmitral and pul­
monary venous flow patterns. 13 LV diastolic dysfunction
therefore is not the sole cause of altered transrnitral flow
patterns, and atrial dysfunction has to be ruled out. The
echocardiographic indicators of atrial dysfunction
include a decreased ratio of systolic to diastolic maxi­
mum pulmonary venous flow velocity in the presence of
normal pulmonary capillary wedge pressures, reduced LA
area change, and reduced mitral annulus motion.13
The thin-wall right ventricle is particularly suscepti­
�le to injury during the period of ischemia and reperfu­
swn and also compensates poorly for any increase in
pulmonary vascular resistance, which often is elevated
in patients with end-stage heart failure. Therefore, it is
not surprising that acute RV failure is more common
than LV failure and accounts for 50% of all cardiac
complications and 1 9 % of all early deaths after heart
transplantation. 14 Once the diagnosis of RV dysfunc­
tion is established, stenosis at the PA anastomosis or
kinking of the PA should first be ruled out. A systolic
gradient higher than 1 0 mm Hg may indicate the
need for surgical revision. TEE should then be used to
optimize RV filling to avoid overdistention of the ven­
tricle and to assess the response to inotropic support.
In the setting of maximum inotropic support and pul­
monary vasodilator therapy, the presence of a small
hyperdynamic left ventricle with a dilated right ventri­
cle (Figure 1 7- 1 ) , especially when accompanied by
marginal urine output, arrhythmias, or coagulopathy,
should prompt the consideration of the implantation

of an RV assist device.
The size and geometry of the atria and the atrial
anast� moses depend entirely on the transplantation
t�chmque �mploye� . In the standard biatrial technique,
d1fferent-s1zed portwns of the native atria are left in
situ (Figure 1 7-2) , resulting in biatrial enlargement,
asynchronous contraction, and intraluminal protrusion
of the atrial anastomoses. This method also often gives
the atria a multicharnber configuration on the TEE
(Figure 1 7-3) . The anastomotic protrusions appear
echo-dense and should not be confused with thrombi,
although thrombi may form along the suture line.
These protrusions may also occasionally contact the
posterior mitral leaflet in systole, or even result in a
mild constriction with a step-up of intraatrial Doppler
flow velocities. Severe cases of supra-mitral valve obstruc­
tion, or acquired cor triatriatum, have been described
:iller heart . transplantation and should be suspected
mtraoperanvely when the LA remnant is markedly
enlarged and LV volume is reduced. Turbulent flow by
color-flow Doppler (CFD) , fluttering of the mitral
valve leaflets, and elevated blood flow velocities by
pulsed-wave Doppler also may aid in the confirmation
of the diagnosis.


TRANSESOP HAGEAL ECHOCARDIOGRAPHY FOR H EART FAI LU RE SU RGERY

A

I

39 1

B

FIGURE 1 7- 1 . Right ventricular d i lation. A: I n the long-axis view, the right ventricle appears to be greater than
two-thirds the size of the left ventricle, and the a pex of the heart includes the right ventricle (arrow). B: I n the short­
axis view, a small, usually hyperdynamic l eft ventricle is seen with a di lated right ventricle. (LV, left ventricle; RV, right
ventricle.)

The integrity of the interatrial septum should be
assessed intraoperatively by using color-flow Doppler
and contrast echocardiography (agitated saline or saline
microcavitation) . Shunts can occur at the atrial anasto­
motic site or through a patent foramen ovale (PFO) .
Although uncommon, shunting through a PFO that is
not apparent preoperatively may become hemodynami­
cally significant postoperatively. AB the relative pressure
difference between the left and right atria changes as a

result of pulmonary hypertension, RV dysfunction, or
tricuspid regurgitation (TR) , right-to-left shunting can
occur and present as refractory postoperative hypox­
emia. 1 5 Identification of a left-to-right shunt across the
interatrial anastomoses also should prompt surgical
repair because it can contribute to progressive RV vol­
ume overload and TR
Spontaneous echo contrast can be detected in up
to 5 5 % of heart transplant recipients. This is usually

A

B

FIGURE 1 7-2. Posttra nspla ntation tra n sesophageal echoca rd iogra phy demonstrati ng con seq uences of the
diffe rent-sized porti on s of the native atria l eft i n situ. A : Two fossa ova le (arrows). 8: Two atrial a p pendages
(arrows). ( PV, p u l monary vein; RA, rig ht atri u m; RV, right ventricle.)


3 92

C H A PTER 1 7

bicaval technique as compared with the standard bia­
trial technique.
The natural history of these regurgitant lesions varies,
but the incidence of severe TR appears to increase
with time, and some patients may require tricuspid
valve repair or replacement for refractory symptoms.
However, in many of these patients, the subvalvular
apparatus was damaged during subsequent endomy­
ocardial biopsy. 1 9 When patients were examined 1 year
after transplantation, those with significant TR were
more symptomatic and had poorer right-side heart
function and greater mortality than those with mild or
no TR. 20,2 1

FIGURE 1 7-3. Anasto motic protrusions (arrow) cre­
a t i n g the i m p ression of a m u lti-chamber left atri u m .

(LA, left atriu m ; LV, left ventricle.)

confined to the donor atrial component and is associ­
ated with thrombi, usually attached to the LA free wall
underneath the protruding suture line. The incidence
of thrombus formation in the left atrium is reduced
with the bicaval anastomosis technique.
The PA anastomosis should be examined for possi­
ble stenosis, and, although rare, kinking or torsion of
the donor or recipient p ulmonary artery should be
ruled out, especially in the setting of RV dysfunction. 16
Color-flow Doppler may detect turbulent flow, and the
pressure gradient should be measured with continuous­
flow Doppler. Pulmonary venous inflow also should be
assessed with color-flow and pulsed-wave Doppler.
Mild to moderate degrees ofTR and mitral regurgi­
tation (MR) are common after heart transplantation.
MR is usually mild, produces an eccentric jet toward
the LA free wall, and has a reported incidence of 48%
to 87%. 16 , 1 7 TR, the most common valvular abnormal­
ity after heart transplantation with a reported inci­
dence of 85%, is usually mild with an eccentric jet
directed toward the interatrial septum. 1 8 TR after heart
transplantation is best quantified by using the ratio of
the maximum area of the regurgitant jet to the RA
area. 1 9 The etiology of atrioventricular valve regurgita­
tion in the transplanted heart is thought to be related
to distortion of annular geometry. Annular distortion
after the standard biatrial anastomotic technique is
predominantly the result of disturbed atrial geometry

and function, whereas donor heart and recipient pericar­
dia! cavity size mismatch is thought to play an impor­
tant role after the bicaval anastomotic technique. This
hypothesis is supported by the fact that the incidence
and severity of TR and MR are reduced after the

Management of Early Postoperative
Hemodynamic Abnorm a l ities in the
I ntensive Ca re U n it

TEE has become an invaluable tool in the management
of seriously ill intensive care patients in whom transtho­
racic acoustic images may be poor. Particular uses in these
circumstances include assessment of biventricular func­
tion, anastomotic problems (kinks, torsion, or stenosis),
valvular abnormalities, sources of systemic emboli, and
the detection of pericardia! tamponade.
Postoperative Fol low- U p Studies of
Ca rdiac Allog raft Fu nction

Echocardiography, a noninvasive means of diagnosing
transplant rejection, plays a significant role in the follow­
up of recipients after heart transplantation. Proposed
echocardiographic indicators of rejection in heart trans­
plant patients are listed in Table 1 7-5 . In addition, two­
or three-dimensional echocardiography may be used to
guide transvenous endomyocardial biopsies to prevent
inadvertent damage to the tricuspid valve and its sup­
porting apparatus. Dobutamine stress echocardiography,
used in the detection of allograft vasculopathy, also has

been shown to have a high negative predictive value for
Table 1 7-5. Echocard iog ra p h i c I nd i cators of
Rejecti o n .

I ncreasing left ventricular mass and left ventricular wa l l
thickness
Increased myocardial echogenicity
New or increasing pericardia! effusion
G reater than 1 0% decrease in left ventricular ejection
fraction
Restrictive left ventricu l a r fi l l i n g pattern (>20% decrease
i n m itra l va lve pressure half-ti me and 20% decrease in
isovolumic relaxation time)
New-onset mitral reg urg itation


TRANSESOP HAGEAL ECHOCARDIOGRAPHY FOR H EART FAI LU RE SU RGERY

determining future cardiac events and death in heart
transplant recipients.22

MECHAN ICAL CIRCUL ATORY SUPPORT
Mechanical circulatory support devices include intra-aortic
balloon pumps and ventricular assist devices (VADs) that
may be inserted for supporting the failing left and/or
right ventricle.
I ntra-aortic Ba l loon Pumps

Intra-aortic balloon pumps (IABPs) are placed periop­
eratively in 2% to 1 2% of cardiac surgical patients,

with the majority being placed intraoperatively. 5 When
IABPs are placed, TEE can be useful in determining the
need for the IABP, assessing for contraindications such
as aortic insufficiency or severe aortic atherosclerosis,
and guiding its placement into the descending aorta.
TEE can also rapidly assess the effects of counterpulsa­
tion upon LV function and determine if there were any
complications such as aortic dissection or aortic valve
perforation. Inappropriate placement is the most com­
mon complication, and inadvertent passage of the
IABP into the aortic arch, left ventricle, subclavian
artery, renal artery, contralateral femoral artery, and
right atrium have all been reported. 23·24
Assessment of IABP placement begins with visuali­
zation of the guidewire within the lumen of the
descending aorta. This is particularly important in the

FIGURE 7 7-4.

A mides­
ophageal descending aorta
long-axis view demonstrates
the aortic l u men and an echo­
dense i ntra-aortic bal loon
pump (IABP) within the aortic
l u men.

I

393

setting of aortic dissection, when identification of the
true aortic lumen may be challenging. Optimal place­
ment of the IABP tip is 3 to 4 em distal to the origin of
the left subclavian artery, or when the tip is seen at the
inferior border of the transverse aortic arch.25 To con­
firm proper placement, the balloon is first identified in
the descending aorta short-axis view. Proper placement
has been defined by the disappearance of the tip of the
IABP from the aortic arch in the upper esophageal aor­
tic arch long-axis view. Placement below the subclavian
artery can also be visualized in a descending aorta long­
axis view by slowly withdrawing the probe until the
subclavian artery is seen at the level of the aortic arch
(which is now seen in cross-section) . The common
carotid artery is sometimes mistaken for the subclavian
artery but can be differentiated by its larger diameter
and by turning the probe to the left (to visualize subcla­
vian) and then to the right (to visualize the common
carotid) . The balloon itself typically appears as an echo­
dense image when deflated (Figure 1 7-4) and a scat­
tered echo image when inflated. A side lobe artifact is
commonly seen when the tip of the IABP is visualized
in the short-axis view.
Left Ventricular Assist Devices

Transesophageal echocardiography plays a critical role
in each step of the management of patients with left
ventricular assist devices (LVADs) , including the pre­
placement evaluation of cardiac structure and function,