External bladder injuries are caused by either blunt or penetrating trauma to the lower abdomen, pelvis, or perineum. Blunt trauma is the more common mechanism, usually by a sudden deceleration, such as in a high-speed motor vehicle crash or fall, or from an external blow to the lower abdomen. The most frequently accompanying injury is a pelvic fracture, occurring in > 95% of bladder ruptures caused by blunt trauma. Other concomitant injuries include long bone fractures and central nervous system and chest injuries. Penetrating injuries, most often gunshot wounds, account for < 10% of bladder injuries.
The bladder is the most frequently injured organ during pelvic surgery. Such injuries can occur during transurethral surgery, gynecologic procedures (most commonly abdominal hysterectomy, cesarean section, pelvic mass excision), or colon resection. Predisposing factors include scarring from prior surgery or radiation therapy, inflammation, and extensive tumor burden.
Bladder injuries are classified as contusions or ruptures based on the extent of injury seen radiographically. Ruptures can be extraperitoneal, intraperitoneal, or both; most are extraperitoneal.
Complications of bladder injuries include infection (including sepsis), persistent hematuria, urinary ascites (free urine in the peritoneal cavity from an intraperitoneal rupture), acute kidney injury, fistula formation, incontinence, and bladder instability.
Mortality with bladder rupture from external trauma can approach 20%; this is due to concomitant organ injuries rather than the bladder injury.
Symptoms and Signs of Bladder Trauma
Symptoms and signs of bladder injuries may include suprapubic pain, inability to void, hematuria, abdominal distention, hypovolemic shock (due to hemorrhage), azotemia, and in the case of intraperitoneal rupture, peritoneal signs. Blunt bladder ruptures almost always present with a pelvic fracture and gross hematuria.
Bladder injuries occurring during surgery are usually identified intraoperatively. Findings can include urinary extravasation, a sudden increase in bleeding, appearance of the bladder catheter in the wound, and, during laparoscopy, distention of the urinary drainage bag with gas.
Diagnosis of Bladder Trauma
Retrograde cystography with plain film x-rays or CT
Symptoms and signs suggestive of bladder injuries are often subtle or nonspecific; therefore, diagnosis requires a high level of suspicion. Diagnosis is suspected on the basis of history, physical examination, radiographic findings (eg, pelvic fracture), and the presence of hematuria (predominantly gross). Confirmation is by retrograde cystography using at least 300 mL of diluted contrast to directly fill the bladder. Plain film x-rays or CT can be used, but CT provides the additional advantage of evaluating concomitant intra-abdominal injuries and pelvic fractures. Drainage films should be obtained only when plain film x-rays are used. If urethral disruption is suspected in a male, urethrography should be performed prior to inserting a urethral catheter.
A rectal examination should be done in all patients with a blunt or penetrating mechanism of injury to assess for blood, which is highly suggestive of a concomitant bowel injury. Additionally, female patients should undergo a thorough pelvic examination to assess for vaginal involvement.
Treatment of Bladder Trauma
Catheter drainage
Sometimes surgical repair
Bladder contusions require only catheter drainage until gross hematuria resolves. Most extraperitoneal ruptures can be managed with catheter drainage alone if the urine is draining freely and the bladder neck, rectum, and vagina are not involved. With bladder neck involvement, surgical exploration and repair are required to limit the likelihood of incontinence. Similarly, surgical management is indicated in cases of persistent gross hematuria, clot retention, or concomitant rectal or vaginal injury. All penetrating bladder injuries and intraperitoneal ruptures due to blunt trauma require surgical exploration. Most bladder injuries occurring during surgery are identified and repaired intraoperatively. Surgical repair of bladder injuries can be done using open or laparoscopic techniques.
Key Points
Most bladder injuries from external trauma are caused by blunt mechanisms and are accompanied by pelvic fractures and gross hematuria.
Consider the diagnosis when there is a compatible mechanism of injury and suprapubic pain and tenderness, inability to void, hematuria, bladder distention, and/or unexplained shock or peritoneal signs.
Confirm the diagnosis using retrograde cystography.
Contusions and most extraperitoneal ruptures can be managed with catheter drainage alone.
Complicated extraperitoneal ruptures and intraperitoneal ruptures should be surgically explored.
Most bladder injuries during surgery are identified and repaired intraoperatively.
