VESICAL TRAUMA

Vesical injury can occur as a result of blunt or penetrating trauma to the lower abdomen and pelvis. It is more commonly associated with blunt trauma such as that sustained from motor vehicle accidents, falls, blows, and during contact sports. Penetrating trauma resulting in vesical injury occurs from gunshot wounds and knife wounds. Bladder injuries can also be iatrogenic from transurethral surgery, gynecologic procedures, laparoscopy, and other intra-abdominal surgery. Bladder injury, particularly bladder rupture, is associated with pelvic fractures in 75% to 83% of patients. However, only 5% to 10% of patients with pelvic fractures will have associated bladder rupture. There is also a high incidence (>85%) of injuries to other organs in patients with bladder rupture. Concomitant bladder rupture is found in 10% to 29% of patients who present with rupture of the posterior urethra, and this is the most common injury to the genitourinary tract associated with bladder rupture. The mortality rate in patients with bladder rupture ranges from 11% to 44% and is mainly attributable to other associated organ injuries.

Anatomy

In children, the bladder is mainly an abdominal organ located behind the anterior abdominal wall. Growth of the bony pelvis allows the bladder to assume its position behind the pubic symphysis by the end of the sixth year of life. In its extraperitoneal location, the bladder is protected by the bony ring of the pelvis. It is attached to the pelvic bones and the lateral pelvic wall by means of various ligaments. The superior surface (dome) of the bladder in women and the dome and a portion of the base of the bladder in men are covered by parietal peritoneum. A fibrous cord, the median umbilical ligament, extends from the apex of the bladder to the umbilicus and is a remnant of the urachus. The dorsolateral ligamentous attachments of the bladder contain the nerves and vascular supply to the bladder. The fascial attachments between the bladder and the pubic bones are termed the pubovesical ligaments in women and the puboprostatic ligaments in men. Ligamentous attachments also connect the bladder anteriorly and laterally to the pelvic side wall.

The arterial supply to the bladder is derived from the superior, middle, and inferior vesical arteries, which are branches of the anterior division of the internal iliac (hypogastric) artery. The vesical venous plexus drains into the internal iliac veins. The sympathetic nerve supply to the bladder originates in the thoracolumbar sympathetic trunks and is via the superior hypogastric plexus to the pelvic plexus, where it joins with the parasympathetic nerves. The parasympathetic nerve supply is from the sacral parasympathetic outflow to the pelvic plexus and then to the bladder.

Mechanism of Injury

Bladder injury occurs as three predominant types: contusion with only intramural injury and extraperitoneal or intraperitoneal bladder rupture. The exact incidence of bladder contusion is not known because of the lack of large studies involving this type of bladder injury. It is a partial-thickness tear of the bladder mucosa with ecchymosis of the bladder wall. It is often associated with a “teardrop” bladder, which occurs as a result of the presence of compressive pelvic hematomas from pelvic fractures. It is usually self-limiting and rarely requires treatment. Extraperitoneal bladder rupture occurs less frequently than intraperitoneal rupture (34% versus 58% of cases). Combined intra- and extraperitoneal rupture is seen in 8% of cases. It was initially believed that bladder rupture, especially extraperitoneal rupture, resulted from the traumatic dislodgement of the bladder from its points of attachment. Penetration of the bladder wall by fragments of the fractured pelvic bones was also thought to be another possible etiologic mechanism. However, Carroll and McAninch noted that only 35% of bladder ruptures in their series were accompanied by ipsilateral pelvic fractures. Hence, it is likely that the bladder may sustain an extraperitoneal rupture when it suffers from a bursting-type injury. In intraperitoneal rupture, the dome of the bladder, which is the weakest portion of the wall, usually gives way, resulting most often in a horizontal tear.

Diagnosis

Patients with bladder injury usually complain of lower abdominal pain and tenderness. Such an injury should be suspected in any patient with a pelvic fracture. Most patients with bladder trauma, including those with bladder contusions, will have gross or microscopic hematuria. Patients with contusion alone are usually able to void, whereas those with a ruptured bladder are often unable to void spontaneously. Acidosis with prerenal azotemia and elevated blood urea nitrogen is sometimes noticeable when there is a delay in diagnosis.

Presence of blood at the urethral meatus mandates performing a retrograde urethrogram. This is performed to rule out urethral injury before catheterization or instrumentation. If the retrograde urethrogram is normal, a urethral catheter is placed, and a retrograde cystogram is obtained. This is performed by instilling at least 250 to 400 cc of water-soluble contrast (cystografin) in the bladder under gravity to ensure adequate distension and visualization of possible areas of rupture. One of the principal reasons for false-negative cystograms is instillation of an inadequate amount of contrast in the bladder. Static anteroposterior, oblique, or lateral films are obtained with the bladder full, and a washout film is obtained after drainage of the contrast material from the bladder. These additional films are useful in evaluating patients with posterior wall ruptures, which may be obscured in the anteroposterior view by a contrast-filled bladder. The drainage film also helps detect residual extravasation.

The cystogram is usually normal in the presence of a bladder contusion. Intraperitoneal rupture results in ill-defined spillage of contrast into the peritoneum. The extravasated contrast may outline loops of bowel or accumulate in the paracolic gutters, beneath the diaphragm or over the bladder, in an hourglass pattern. Extraperitoneal rupture is seen as streak-like extravasation of contrast confined to the pelvis on retrograde cystogram. Corriere and Sandler further distinguished extraperitoneal ruptures as simple (confined to the perivesical space) or complex (extravasation into scrotum, retroperitoneum, abdominal wall, etc.). Displacement of the bladder by a pelvic hematoma can result in a “teardrop”-shaped bladder on cystogram.

Recently, examination of a contrast-filled bladder during CT scan has been used as a method of assessing injury. This is particularly applicable in patients who first undergo abdominal CT scans to rule out suspected visceral injuries. In these situations, the ability to simultaneously evaluate the bladder would obviate the need for an additional plain-film cystogram. However, during routine abdominopelvic CT scan, the bladder may not be adequately distended to allow evaluation for rupture. Mee et al. reported on two patients who were evaluated for bladder rupture on CT scan. Both patients received intravenous and oral contrast, and their Foley catheters were clamped to allow bladder filling. In spite of this, one of the patients had a false-negative result. The bladder rupture was subsequently visualized on plain-film cystography in both cases. The results of CT cystography are better when the bladder is filled in a retrograde fashion with large volumes of contrast (>350 cc). Intraperitoneal bladder rupture can be distinguished from extraperitoneal rupture on CT scan. Presence of contrast around the bladder and in the paracolic gutters on either side and around abdominal viscera such as the liver indicates intraperitoneal rupture. In the case of extraperitoneal rupture, contrast extravasation is usually seen around the bladder, in the presacral space and in the retroperitoneum anterior to the great vessels. Bladder contusions may be seen on CT scan as intramural hematomas. In spite of the improved accuracy of CT scans, plain-film cystography is still the diagnostic modality of choice for detecting bladder ruptures. The accuracy of CT cystography may be significantly improved if retrograde bladder filling with adequate amounts of contrast is employed. In these situations, its accuracy may even approach that of plain-film cystography. Computed tomographic cystography may be particularly useful in the select group of patients who undergo a CT scan as their initial radiologic evaluation and are unable to undergo routine cystography because of the nature of their injuries or time constraints.

Intraoperatively, bladder rupture can be diagnosed by extravasation of saline, sterile milk, methylene blue, or indigo carmine, which is instilled in the bladder through a Foley catheter. In some situations, an intravenous pyelogram may be required to rule out other ureteral or renal injuries.

Indications for Surgery

  1. Intraperitoneal bladder rupture.

  1. Bladder rupture or perforation sustained during another surgical procedure.

  1. Extraperitoneal bladder rupture in the presence of other intra-abdominal injuries requiring surgical intervention.

  1. Extraperitoneal bladder rupture with the bladder being inadequately drained by urethral catheter drainage.

Alternative Therapy

Alternative treatments of bladder trauma are predominantly Foley catheter drainage, which is indicated in patients with bladder contusions and extraperitoneal extravasation. Injuries occurring during other procedures such as laparoscopic surgery may be repaired laparoscopically.

Surgical Technique

Intraperitoneal Bladder Rupture

Intraperitoneal bladder rupture requires immediate surgical repair. The abdomen is opened through a vertical lower midline incision, which affords better exposure and is extendable in case a laparotomy is required. The rupture, which is usually placed horizontally on the dome of the bladder, is identified. In some situations, this may require instillation of saline or dye in the bladder through a previously placed urethral catheter. In cases where additional extraperitoneal ruptures are suspected, the opening in the bladder wall can be extended to allow better visualization of the interior and bladder neck. These extraperitoneal tears can be closed from inside the bladder in one or two layers using running absorbable suture (3-0 chromic or polyglycolic/polygalactic acid). The intraperitoneal rupture(s) are closed in at least two layers using running 3-0 chromic or polyglycolic/polygalactic acid suture. The mucosa, muscle, and peritoneum are all closed in separate layers. The bladder is filled with saline after completion of the closure to evaluate for leaks. If any leaks are detected, they can be closed using interrupted figure-of-eight sutures.

In some situations, bony spicules that have penetrated the bladder wall may need to be removed before closure of the bladder. In cases of penetrating trauma or erosion of the bladder wall by pelvic abscess, nonviable tissue must be debrided, and the edges of the perforation freshened prior to closure. In these cases, the tissue may be extremely friable, and a single-layer closure may need to be performed. The ureteral orifices should be identified and observed to ensure normal efflux of urine. This may be done after administration of intravenous indigo carmine to facilitate visualization. If efflux of urine is not seen, proximal ureteral obstruction, especially by fractured bony fragments, should be ruled out. This can be done by performing a retrograde or intravenous pyelogram on the operating table.

An 8-Fr Malecot suprapubic catheter is placed through a separate cystotomy to drain the bladder. Care must be taken not to disturb the pelvic hematoma that is invariably present. Disruption of the pelvic hematoma may give rise to significant bleeding. This can be controlled by packing the area with Gelfoam, Surgicel, or laparotomy tapes. The abdomen can be temporarily closed with the packing in place for about 24 hours, and the packing removed at the time of reexploration. In extreme cases, angiographic embolization of the pelvic vessels may be necessary.

A ½-inch Penrose drain is placed adjacent to the bladder and left in place for 48 hours. In some cases, if the pelvic hematoma has not been disturbed, and the bladder closure is truly watertight, drains can be omitted altogether. The abdominal fascia and skin are closed in the usual fashion.

In patients with small bladder ruptures, we have opted to drain the bladder postoperatively via a urethral catheter and have noted no significant adverse effects. The catheter is left in place for 7 to 10 days. A gravity cystogram is obtained at the end of this time to ensure absence of extravasation. The catheter is then removed if no extravasation is evident on cystogram.

Iatrogenic bladder injury, if suspected to have occurred during other operative procedures, should be documented by instillation of methylene blue or indigo carmine in the bladder and noting any extravasation. The rupture or tear can be closed primarily in two or three layers using absorbable suture as in other cases of rupture. Bladder perforations sustained during laparoscopic procedures can be diagnosed by noting distention of the urethral catheter drainage bag with gas. These injuries can be repaired as described previously by laparotomy or even laparoscopically.

Extraperitoneal Bladder Rupture

Until the 1970s, extraperitoneal bladder rupture was managed as an intraperitoneal rupture. Since then several studies have demonstrated that these injuries can be managed nonoperatively. Corriere and Sandler successfully managed 41 patients with extraperitoneal bladder rupture by prolonged urethral catheterization alone. All patients healed the bladder injury spontaneously without complications. Since then, other studies have duplicated these results.

Isolated extraperitoneal rupture can be treated by simple urethral catheter drainage. Once urethral injury has been ruled out by means of a retrograde urethrogram, a urethral catheter is placed. The catheter is left in place for 10 to 14 days. Repeat cystograms are performed at the end of this period. If no extravasation is observed, the catheter can be removed. If any contrast extravasation is evident on the cystogram, catheter drainage is continued. Cystograms are repeated at weekly intervals until no extravasation is demonstrable. A majority of extraperitoneal ruptures treated in this manner will heal by 2 weeks, and almost all will show healing within 3 weeks.

Severe bleeding with clots or sepsis should prompt surgical exploration even in cases of extraperitoneal rupture. If patients are undergoing laparotomy for other intra-abdominal injuries, it is reasonable to repair extraperitoneal ruptures surgically.

Outcomes

Complications

Some patients may notice persistent urgency and increased frequency of micturition after repair of bladder ruptures. These symptoms are usually temporary and tend to subside with time. Vesical neck injuries increase the risk of subsequent incontinence, and attention should be paid to careful repair of these injuries. Infection of pelvic hematomas can result in abscess formation requiring prolonged drainage and antibiotic treatment. This can be prevented to some extent by taking care to avoid disrupting the hematoma intraoperatively. Unrecognized injury to adjacent structures can lead to subsequent vesicovaginal or vesicoenteric fistula formation. Otherwise, this complication is uncommon.

Complications such as clot retention and pseudodiverticulum formation are seen in fewer than 10% of patients treated with catheter drainage alone for extraperitoneal rupture. Significant sepsis, delayed healing, formation of bladder calculi, and vesicocutaneous fistula formation have been noted to occur in patients treated with urethral or suprapubic catheter drainage for extraperitoneal rupture. These patients most often had poorly functioning catheters or did not receive prophylactic antibiotics. Hence, it is important to ensure that urethral catheters are functioning adequately when used in these situations. Use of larger catheters and resorting to immediate open repair if catheters remain nonfunctional after 24 to 48 hours will help avoid these complications. Prophylactic antibiotics with gram-negative coverage, when administered for the duration of catheterization, will help prevent urinary tract infections.

Results

Open repair with adequate closure of the rupture is almost uniformly successful in all patients treated in this manner, and 74% to 87% of patients managed with urethral catheter drainage for extraperitoneal rupture will show evidence of healing by 10 to 14 days. The remainder will heal with an additional week to 10 days of catheter drainage.

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