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 urinary ascites (free urine in the peritoneal cavity) due to intraperitoneal rupture, infection (including sepsis), persistent hematuria, incontinence, bladder instability, and fistula. Mortality with bladder rupture from external trauma can approach 20%; this is due to concomitant organ injuries rather than the bladder injury.
Symptoms may include suprapubic pain and inability to void; signs may include hematuria, suprapubic tenderness, distention, hypovolemic shock (due to hemorrhage), 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.
Symptoms and signs 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, and the presence of hematuria (predominantly gross). Confirmation is by retrograde cystography using 350 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 done before 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.
Bladder contusions require only catheter drainage until gross hematuria resolves. Most extraperitoneal ruptures require only catheter drainage if urine is draining freely and the bladder neck is spared. 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 both. All penetrating trauma and intraperitoneal ruptures due to blunt trauma require surgical exploration. Most bladder injuries occurring during surgery are identified and repaired intraoperatively.
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. Intraperitoneal ruptures should be surgically explored.
Most bladder injuries during surgery are identified and repaired intraoperatively.