Pediatric emergency medicine trisk 831

CLINICAL PEARLS AND PITFALLS
Ureteral injuries are often missed during the initial evaluation with less
than 50% of patients diagnosed within 24 hours of presentation. Avulsion
of the ureter should be suspected when the CT urogram (10-minute
delayed imaging after IV contrast administration) demonstrates
extravasation of contrast material and nonfilling of the affected ureter. CT
findings suggestive of renal pelvis or ureteral injury include medial
perirenal extravasation of contrast material, a circumrenal urinoma, and
the lack of opacification of the ureter distal to the injury. However, CT
scan has been shown to be poorly sensitive for ureteral injury, identifying
only 33% of cases in some series. In case in which suspicion for ureteral
injury is high, urologic consultation is necessary as retrograde pyelogram
is a more reliable examination and offers the potential opportunity for
therapeutic intervention.

Current Evidence
Blunt trauma usually involves the UPJ. Disruption of the ureter from the renal
pelvis results from stretching of the ureter by sudden hyperextension of the trunk.
Traditionally, this injury has been described more often in children.
Penetrating injuries may occur at any point along the length of the ureter and
are associated with injuries to other intra-abdominal organs in up to 90% of cases.
Stab wounds rarely cause ureteral injuries.
Ureteral injuries can occur iatrogenically during surgical procedures involving
the retroperitoneum as the ureters may be obscured by bleeding or fibrosis. While
these situations occur far less common in children than adults, a high suspicion
should be maintained in patients presenting with ongoing symptoms after
retroperitoneal surgery, most commonly gynecologic, colorectal, vascular, or
urologic procedures.

Clinical Considerations
Clinical Recognition

Trauma to the ureter should be suspected in patients presenting with fracture of
the transverse process of a lumbar vertebra. Pelvic fracture, hip fracture, lower rib
fracture, splenic laceration, liver laceration, and diaphragmatic rupture have also
been reported in association with ureteral injuries. Gunshot wounds with a bullet
course through the retroperitoneum should also prompt a high level of suspicion.


The physical examination may be unremarkable. However, an enlarging flank
mass in the absence of signs of retroperitoneal bleeding suggests urinary
extravasation. Hematuria is an unreliable sign. The urinalysis may be normal in
30% of confirmed cases. When the diagnosis has been delayed, ureteral injury
may manifest with fever, chills, lethargy, leukocytosis, pyuria, bacteriuria, flank
mass or pain, fistulas, urinoma, peritonitis, and ureteral strictures.

Management/Diagnostic Testing
As mentioned above, the diagnosis of ureteral injury should be entertained when
children present with penetrating abdominal injuries. A CT urogram can suggest
the presence of ureteral injury when the ureter does not opacify with contrast on
delayed images and/or there is urinary extravasation medial to the renal hilum or
along the length of the ureter.
Retrograde pyelogram may be considered if ureteral injury is suspected. This
generally requires sedation or anesthesia, and involves passing dye in a retrograde
fashion from bladder into the ureter with fluoroscopic evaluation.

Clinical Indications for Discharge or Admission
Given the strong association of ureteral injuries with other severe abdominal
injuries, most children with ureteral injury are admitted to the hospital. Urologic
consultation is necessary for children with suspected ureteral injury. These
injuries require diversion of urine with a ureteral stent or nephrostomy tube.
Extensive injuries may require definitive repair in an immediate or delayed

fashion.

BLADDER
Goal of Treatment
The goal of evaluation in the ED is recognition of bladder injuries, determining if
they are extra- or intraperitoneal, and obtaining prompt urologic consultation.
CLINICAL PEARLS AND PITFALLS
Bladder injuries may occur after blunt or penetrating trauma. Blunt
trauma secondary to motor vehicle accidents is the leading cause. More
than 80% of bladder injuries are associated with pelvic fractures;
however, only 10% of patients with pelvic fractures sustain lower urinary
tract injury. The probability of having an associated bladder injury
increases proportionally with the number of fractured pubic rami.


Current Evidence
During childhood, the bladder has a higher abdominal location, which renders the
organ more susceptible to injury than in adults. The bladder can also be more
easily damaged when full. The risk for this injury is especially increased in the
setting of improperly fastened seat belts and lap belts.
Bladder injuries are classified as extraperitoneal, intraperitoneal, or combined.
Extraperitoneal injuries are more frequently associated with pelvic fractures of
the anterior ring and may be related to either laceration or penetration from a
bone spike, irrespective of bladder volume at the time of injury. In contrast,
intraperitoneal injuries, which account for approximately two-thirds of major
bladder injuries, are usually caused by blunt trauma, resulting in a burst
mechanism to a full, distended bladder. Combined injuries are usually seen with
gunshot wounds. Bladder injuries may range from contusions to rupture.
Contusions are incomplete, nonperforating tears of the mucosa. Complicated
injuries may involve the bladder, urethra, sacral plexus, and supporting structures

of the anorectal region.
Bladder neck injuries are uncommon, but serious as this may affect continence
or lead to extravasation into other areas such as the medial thigh. Such injuries
have been reported to be more common in children than in adults because of the
undeveloped prostate and are often in association with a pelvic fracture. The
injury may be due to longitudinal lacerations or lacerations that extend to the
proximal urethra.

Clinical Considerations
Clinical Recognition
Hematuria and dysuria are symptoms commonly seen at presentation. Nearly
100% of patients with rupture of the bladder have gross hematuria. Microscopic
hematuria is associated with less severe injuries such as contusions. Patients with
intraperitoneal ruptures may develop a palpable fluid wave from extravasation of
urine into the peritoneal cavity and peritoneal irritation with signs of peritonitis.
Elevated levels of blood urea nitrogen in the serum are out of proportion to
creatinine resulting from more rapid peritoneal reabsorption of urea.
Patients with myelodysplasia who have undergone bladder augmentation may
experience spontaneous bladder rupture in the presence of infection, bacteremia,
or overdistension. Suspicion must be high as they may lack the classic
presentation seen in sensate patients. Symptoms and signs of sepsis, as well as
shoulder pain, may be encountered at presentation. Emergent exploration is
indicated after a cystogram is completed.


Urethral catheterization must be avoided if physical examination reveals blood
at the urethral meatus or a high-riding prostate as urethral injury is possible.
Urologic consultation is required.

Initial Assessment/Diagnostic Testing

A large, prospective series of pelvic fractures and lower genitourinary tract injury
in pediatric patients found that imaging is not required if patients are stable, have
a normal genitourinary examination, do not have gross hematuria, and do not
have multiple associated injuries. Diagnostic evaluation is indicated in patients
who sustain pelvic or lower abdominal trauma with gross hematuria, inability to
void, abnormal external genitourinary examination, or multiple associated
injuries.
Evaluation begins with a plain radiograph to exclude a pelvic fracture. Fracture
types that have been associated with bladder injury include widening of the
sacroiliac joint, symphysis pubis, and fractures of the sacrum. If a pelvic fracture
is not identified, the urethra can be catheterized and a cystogram is performed.
CT cystography should be performed for patients with suspected bladder injury
after placement of a urethral catheter. Sagittal and coronal multiplanar images
may be helpful in identifying most sites of bladder rupture. CT cystography does
offer some advantages over plain cystography for patients undergoing CT
scanning for the evaluation of other associated blunt injuries. CT scanning
provides expeditious scanning of the head, chest, abdomen, and pelvis;
interpretation is often less affected by overlying bone fragments from pelvic
fractures and spine boards than in the plain radiographic cystogram, and the CT
can detect small amounts of intra- and extraperitoneal fluid, especially in the
posterior position without need for a postdrainage film. The disadvantages of CT
cystography include the much higher radiation exposure and cost than those of
plain radiographs. Currently, the CT cystogram is recommended, when indicated,
for patients undergoing CT scanning for other associated blunt trauma–related
injuries.
With either modality, the bladder must be filled to an age-appropriate volume
(∼350 cc in adults) to avoid missing injuries due to underdistension.

Management
With few exceptions, treatment of bladder rupture is determined by whether the

urine extravasation is confined to the extraperitoneal space or is intraperitoneal.
Extraperitoneal bladder rupture can generally be managed by urethral catheter or
suprapubic drainage. Extraperitoneal injuries with a bony fragment or foreign
body in the bladder require surgical exploration.