Bladder and Urethral Injuries

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

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^[1]

Genitourinary trauma is seen in both sexes and in all age groups but is more common in males. The kidney is the most commonly injured organ in the genitourinary system and renal trauma is seen in up to 5% of all trauma cases and in around 10% of all abdominal trauma cases.

Genital trauma is much more common in males, due to anatomical considerations and more frequent participation in physical sports, violence and war-fighting.

In young children the bladder is an abdominal organ esp when full and is more prone to blunt trauma injuries having only relatively thin abdominal musculature protecting much of it.

Blunt trauma (the majority)

• Deceleration injuries usually produce both bladder trauma (perforation) and pelvic fractures.
• The most common mechanisms of blunt trauma are road traffic accidents, falls and assaults.^[2]
• Because the bladder is located within the bony structures of the pelvis, it is protected from most external forces.
• Approximately 4% 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 most common being to the spleen and rectum.

Penetrating trauma

• The most common cause of penetrating trauma is gunshot wounds and stabbings.
• Penetrating trauma tends to be more severe and less predictable than blunt trauma. Bullets have high kinetic energy and have the potential for greater destruction. They are most often associated with multiple organ injuries.
• The combination of penetrating trauma to both rectum and the urinary system can be 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 can occasionally occur in women undergoing a caesarean delivery.
• Adhesions from previous caesarean deliveries are a risk factor for bladder trauma.^[3]
• When bladder injuries remain unrecognised it can lead to vesicouterine fistulas and other problems.

Gynaecological trauma

• Iatrogenic bladder injury may occur during a vaginal or abdominal hysterectomy. Laparoscopic hysterectomy is associated with higher risk of bladder or ureter injury.^[4]
• Blind dissection in the incorrect tissue plane between the base of the bladder and the cervical fascia results in bladder injury.
• The main risk factors for bladder trauma are previous surgery, inflammation and malignancy.^[5]

Urological trauma

• Perforation of the bladder can occur during a bladder biopsy, transurethral resection of the prostate (TURP) or transurethral resection of a bladder tumour (TURBT).^[6]

Orthopaedic trauma

• Orthopaedic pins and screws can 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.

Other iatrogenic trauma

• The bladder can be occasionally be perforated in infants who have inguinal canal surgery.

Idiopathic bladder trauma

• Alcohol-dependent people and those individuals whose drinking of large quantities of fluids has become chronic are susceptible to this type of injury.
• Previous bladder surgery is a risk factor.
• This type of injury may result from a combination of bladder overdistension and minor external trauma - eg, a simple fall.

Urethral trauma

• The most common type of urethral trauma seen in urological practice is iatrogenic, due to catheterisation, instrumentation, or surgery.
• Radiotherapy can lead to urethral strictures.
• Iatrogenic injuries to the urethra can be a complication of major pelvic procedures.
• The posterior urethra or urinary bladder may be injured in patients who sustain fractures of the bony pelvis.
• The anterior urethra is most commonly injured by blunt or 'fall-astride' trauma.
• Penile fractures can occur during sexual intercourse. The urethra is involved in around 20% of these cases.^[7]
• Urethral injuries are extremely rare in females.

Presenting features

There may be hypovolaemia, hypotension and shock.

Clinical signs of bladder injury are relatively nonspecific.

The following may occur:

• Macroscopic haematuria. Traumatic bladder rupture is strongly correlated with the combination of pelvic fracture and gross haematuria and strongly indicates the need for further imaging.
• However, approximately 5-15% of patients with bladder rupture only have non-visible 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.
• If there is blood at the urethral meatus, always suspect a urethral injury.
• Approximately 10-20% of men with a posterior urethral injury have an associated bladder injury.

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.
• Swelling of the scrotum, perineum, abdominal wall and/or thighs may occur.

Investigations

The decision regarding radiographic imaging is based on the clinical findings and the mechanism of injury.

Cystography

Cystography is the investigation of choice for those patients with non-iatrogenic bladder injury. Plain and CT cystography have similar sensitivities and specificities. A retrograde urethrography is the standard diagnostic investigation for the acute evaluation of a male urethral injury.

Cystoscopy

Cystoscopy is the preferred method for detection of intraoperative bladder injuries, as it may directly visualise the laceration. A routine cystoscopy is recommended at the end of a hysterectomy and every major gynaecological procedure. A flexible cystoscopy can also be used both to diagnose and to manage an acute urethral injury.

CT scan

This is the best test for assessment of stable patients. CT is more sensitive and specific than intravenous pyelogram (IVP), ultrasonography or angiography. Intravenous contrast can be given for renal evaluation.

Ultrasound scan

An ultrasound scan alone is not sufficient in the diagnosis of bladder trauma. An ultrasound scan can be useful to guide the correct placement of a catheter in the acute setting.

Retrograde urethrography

This is a useful investigation to evaluate the urethra. It is not, however, done in an emergency setting.

Management

The European Association of Urology developed guidelines for the appropriate management of genitourinary trauma.^[1]Any life-threatening injuries should be dealt with first.

Medical therapy

Most minor bladder injuries can be managed safely with simple catheter drainage (ie urethral or suprapubic), bed rest and observation. 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. Most extraperitoneal bladder injuries heal within three 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

• Intraperitoneal ruptures can lead to sepsis and carry a higher mortality than extraperitoneal injuries. They tend to be large and most commonly occur at the dome of the bladder. All these injuries should be treated with prompt surgical exploration. Urine can continue 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 taken to theatre immediately. 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.
• Conservative treatment may be undertaken for those with uncomplicated intraperitoneal injury after transurethral resection of the bladder (TURB) or not recognised during surgery, but only in the absence of peritonitis and ileus.

Extraperitoneal injury

• Extraperitoneal injuries can be managed successfully with a conservative strategy.
• Catheter drainage followed by a cystogram after 10 days is successful in the majority of cases, with almost all ruptures healed by three weeks.
• Trauma patients who require emergency laparotomy may have large or complex injuries repaired at the same time.

Urethral injuries
Management of urethral injury is based around the type of injury. Urethral or suprapubic catheterisation should be undertaken.^[8]The aim of treatment in urethral trauma is to maintain continence and potency and to reduce the occurrence of strictures. In many cases a urethroplasty is undertaken at a later stage after a stricture has developed.

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.

• The patient should return in 7-10 days for staple removal and wound check.
• The cystogram should be 7-14 days after the injury.
• 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. Erectile dysfunction occurs in 20-60% of patients after traumatic urethral rupture.^[9]

Prognosis

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