The urinary bladder occupies the deep pelvic cavity and is well protected. This is the reason why it can rarely be traumatised. However it can suffer traumas which can cause extraperitoneal and intraperitoneal ruptures.^1,2

Gross haematuria is the hallmark of bladder injury. Physicians evaluating patients with blunt or penetrating lower abdominal trauma must have a high index of suspicion for urological injury, especially bladder and urethral injuries.

Aetiology

• Blunt trauma (60-85%)
  Deceleration injuries usually produce both bladder trauma (perforation) and pelvic fractures.
  • The most common mechanisms of blunt trauma are road traffic accidents (87%), falls (7%), and assaults (6%). ³
  • Because the bladder is located within the bony structures of the pelvis, it is protected from most external forces.
  • Approximately 10% of patients with pelvic fractures also have significant bladder injuries.
  • The likelihood of the bladder to sustain injury is related to its degree of distention at the time of trauma.
  • Injury may occur if there is a blow to the pelvis that is severe enough to break the bones and cause bone fragments to penetrate the bladder wall.
  • Generally the bladder injury in these cases is associated with other injuries as well, the commonest being to the spleen and rectum.
  • The posterior urethra or urinary bladder may be injured in patients who sustain fractures of the bony pelvis.⁴
• Penetrating trauma(15-40%)
  • The most common cause of penetrating trauma is gunshot wounds (85%), followed by stabbings (15%).³
  • Abdominal and/or pelvic organ injuries are often also present.
  • Combined penetrating trauma of the rectum and urinary bladder is rare, and constitutes a diagnostic and therapeutic challenge.
  • The combination of penetrating trauma to both rectum and the urinary system is associated with high morbidity and mortality.
• Obstetric trauma
  • During prolonged labour or a difficult forceps delivery, persistent pressure from the fetal head against the mother's pubis can lead to bladder necrosis.
  • Direct laceration of the urinary bladder is reported in 0.3% of women undergoing a Caesarean delivery.³
  • Previous Caesarean deliveries, and the adhesions that can remain subsequently, are a risk factor.
  • Scarring may cause obliteration of normal tissue planes and be responsible for an inadvertent incision into the bladder.
  • When bladder injuries remain unrecognised it can lead to vesicouterine fistulas and other problems.
• Gynaecological trauma
  • Bladder injury may occur during a vaginal or abdominal hysterectomy.
  • Blind dissection in the incorrect tissue plane between the base of the bladder and the cervical fascia results in bladder injury.
• Urological trauma
  • Perforation of the bladder during a bladder biopsy, transurethral resection of the prostate (TURP) or transurethral resection of a bladder tumour (TURBT) is not uncommon.
  • Incidence of bladder perforation has been reported as 36% following bladder biopsy.³
• Orthopaedic trauma
  • Orthopaedic pins and screws can commonly perforate the urinary bladder, particularly during internal fixation of pelvic fractures.
  • Thermal injuries to the bladder wall can occur during the setting of cement substances used to secure arthroplasty prosthetics.
• Idiopathic bladder trauma
  • Alcoholics and those individuals who chronically drink large quantities of fluids are susceptible to this type of injury.
  • Previous bladder surgery is a risk factor. In reported cases, all bladder ruptures were intraperitoneal.
  • This type of injury may result from a combination of bladder overdistension and minor external trauma, e.g. a simple fall.

Classification^5,6

Presenting features

There may be hypovolaemia, hypotension and shock.
Clinical signs of bladder injury are relatively nonspecific. The triad of symptoms usually present includes:

• Macroscopic haematuria. Haematuria invariably accompanies all bladder injuries. More than 98% of bladder ruptures are associated with gross haematuria, and 10% are associated with microscopic haematuria.
• Suprapubic pain or tenderness. Most patients with bladder rupture complain of suprapubic or abdominal pain.
• Difficulty or inability to void. Many can still void, but the ability to urinate does not exclude bladder injury or perforation.

An abdominal examination may reveal:

• Distention, guarding, or rebound tenderness.
• Absent bowel sounds and signs of peritoneal irritation, indicating a possible intraperitoneal bladder rupture.
• Bruising in suprapubic region.

If there has been a road traffic accident or a crush injury, bilateral palpation of the bony pelvis may reveal abnormal motion. This indicates an open-book fracture or a disruption of the pelvic girdle.

Investigations

Cystogram

The criterion standard for imaging a suspected bladder injury is a well-performed retrograde cystogram. A properly performed cystogram consists of an initial kidney-ureter-bladder (KUB) film, followed by anteroposterior (AP) and oblique views of the bladder filled with contrast, plus another AP film obtained after drainage.

Retrograde urethrography

If there is blood at the urethral meatus, always suspect a urethral injury. This is an absolute indication for retrograde urethrography. Approximately 10-20% of men with a posterior urethral injury have an associated bladder injury. Do not place a urethral catheter in these patients. Passage of a urethral catheter may convert a partially disrupted urethra into a complete tear. Place a Foley catheter only after urethral injuries are excluded.

CT scan

This is often the first test performed in patients with blunt abdominal trauma. The CT scan of the pelvis provides information on the status of the pelvic organs and bony pelvis and has replaced conventional cystography as the most sensitive test for bladder perforation. Most patients will have multiple injuries and require abdominal or pelvic CT scans as part of their trauma evaluation. If the bladder findings of the CT scan are equivocal, a separate contrast cystogram may still be required. CT cystography, performed as part of the trauma assessment, removes the need for separate procedures.⁷

Management

The European Association of Urology (EAU) developed guidelines for the appropriate management of genito-urinary trauma.⁸
In suspected renal injuries the haemodynamic situation of the patient is the benchmark for the diagnostic and therapeutic algorithm. Life-threatening injuries should dealt with first.

Medical therapy

Most extraperitoneal ruptures can be managed safely with simple catheter drainage (i.e. urethral or suprapubic).⁹ The catheter should be left in situ for 7-10 days, and then a cystogram should be performed. Approximately 75-85% of the time, the laceration is sealed and the catheter is removed for a voiding trial.^10,11
Most extraperitoneal bladder injuries heal within 3 weeks. If surgery is required for associated injuries, extraperitoneal ruptures may be repaired at the same time, as long as the patient is stable.

Surgical therapy

Intraperitoneal bladder rupture

• Most require surgical exploration, as they do not heal with catheterisation alone.¹² Urine continues to leak into the abdominal cavity, resulting in urinary ascites, abdominal distention, and electrolyte disturbances.
• All gunshot wounds to the lower abdomen should be explored. Patients who have high-velocity missile trauma should be immediately taken to theatre. Here the bladder injuries can be repaired at the same time as any visceral injuries.
• Stab wounds to the suprapubic area involving the urinary bladder are managed selectively. Obvious intraperitoneal injuries should be surgically repaired.

• Bladders with extensive extraperitoneal extravasation are often repaired surgically.
• Early surgical intervention in these cases decreases the length of hospitalisation and potential complications. It also promotes early recovery.

Follow-up

Patients sustaining extraperitoneal and complex intraperitoneal bladder disruptions require routine cystogram follow-up.
In those patients undergoing repair of a simple intraperitoneal bladder disruption, however, routine follow-up cystograms do not affect clinical management.¹³

• The patient should return in 7-10 days for staple removal and wound check.
• The X-ray cystogram should be 10-14 days after surgery.
• If the cystogram finding is normal, the urethral catheter can be removed.
• Advise the patient that they may return to normal activity 4-6 weeks after surgery.

Complications

Potential complications of bladder surgery:

• Urinary extravasation
• Wound dehiscence
• Haemorrhage
• Pelvic infection
• Small-capacity bladder
• De novo urge incontinence
• Obstructive uropathy

Other complications:

• Despite technically good reconstruction, urinary extravasation through the bladder closure may occur. This usually responds to extended catheter drainage.
• Abdominal fascial dehiscence presents as persistent drainage from the incision site.
• Violation of pelvic haematomas during surgery results in severe haemorrhage. If infected, pelvic haematomas may become pelvic abscesses.
• Aggressive surgical debridement of the bladder may result in a small bladder, giving rise to bladder spasms and urge incontinence. Over time, the bladder may gradually enlarge to more normal volumes.
• Impotence is common in patients with extensive perineal injuries.

Prognosis

Traumatic bladder ruptures, once uniformly fatal, are currently managed quite successfully. Timely evaluation and proper management are critical for the best outcomes.