Intraperitoneal Bladder Rupture

Intraperitoneal bladder rupture is a full thickness tear of the peritoneum covered dome or posterior wall, so urine leaks into the peritoneal cavity. It accounts for roughly 25 to 40% of bladder ruptures. Extraperitoneal rupture makes up about 55 to 65%, and combined injury about 5 to 12%.

Causes are blunt lower abdominal trauma to a distended bladder (often with alcohol), penetrating injury, iatrogenic injury (transurethral resection of bladder tumour, gynaecological or hernia surgery, trocar placement), and spontaneous rupture in weakened bladders (radiation, tuberculosis, chronic retention, tumour, severe cystitis, augmentation cystoplasty). Neonatal rupture occurs with catheterisation or obstruction.

Pathophysiology. A sudden rise in intravesical pressure against a full bladder tears the dome. Urine in the peritoneum is reabsorbed across the membrane, so urea, creatinine, potassium and chloride rise and sodium falls.

The result is hyperkalaemia, hyponatraemia and hyperchloraemic metabolic acidosis without true renal failure. Initial chemical peritonitis becomes bacterial if untreated.

Lower abdominal pain, tenderness and distension, inability to void or passage of small volumes, gross haematuria in most, suprapubic bruising, ileus and peritonism. Delayed presentation shows urinary ascites with distension, nausea, vomiting, weakness and apparent renal failure. A catheter that returns little urine despite a distended abdomen is typical.

Peritonitis or haemodynamic instability, hyperkalaemia with ECG changes, suspected bowel injury, and delayed presentation with sepsis need immediate escalation.

• Gross haematuria with pelvic fracture, or lower abdominal trauma with haematuria, needs CT cystography. Fill retrogradely through a clamped catheter with 300 to 350 mL of dilute water soluble contrast in adults, or until the bladder is full. In children use (age in years + 2) x 30 mL. Take pre-fill, full and post-drain images.
• Findings: contrast outlining bowel loops, mesenteric folds and paracolic gutters. Routine contrast CT with passive filling is inadequate.
• Urea, creatinine and electrolytes. Peritoneal fluid creatinine over the serum value, usually well over, supports the diagnosis on diagnostic paracentesis.
• Exclude urethral injury by urethrography before catheterisation when there is blood at the meatus.

Differential diagnosis.

• Extraperitoneal bladder rupture or combined rupture
• Urethral injury
• Ureteric or renal injury
• Solid organ injury with haemoperitoneum
• Bowel perforation
• Ascites of another cause
• Neonatal rupture with posterior urethral valves

• Resuscitate. For hyperkalaemia with ECG changes give calcium gluconate 10% 10 mL intravenously over 5 to 10 minutes, repeated if changes persist, plus soluble insulin 10 units with glucose 25 g intravenously. These are temporising, and drainage and repair correct the derangement.
• Urethral catheter of 16 to 18 Fr once urethral injury is excluded.
• Surgical exploration and primary two layer closure for all intraperitoneal ruptures: running full thickness inner layer and seromuscular outer layer, with 2/0 or 3/0 absorbable suture. Inspect the bladder interior, ureteric orifices and trigone, exclude bowel injury, and drain the peritoneum. Laparoscopic repair is feasible in stable patients.
• Catheter for 7 to 14 days, with cystography before removal after extensive, delayed or high risk repair (radiation, steroids, diabetes).
• Antibiotics: ceftriaxone 1 g intravenously as a single preoperative dose (2 g if septic). For peritonitis, ceftriaxone 2 g intravenously once daily with metronidazole 500 mg intravenously every 8 hours, stopped once infection is controlled, commonly after 5 to 7 days.
• Catheter drainage alone is acceptable only for small iatrogenic perforations recognised promptly during endoscopic surgery, with no peritonism or bowel injury, catheter for 7 to 14 days and a repeat cystogram. Evidence is limited, and the threshold for surgery is low.

Special groups. Perforation of an augmented bladder presents with abdominal pain and is often missed, and needs urgent CT cystography and surgery. In neonates, treat the cause (posterior urethral valves) after repair.

Monitoring. Daily potassium and creatinine until normal, fluid balance, and cystogram at 7 to 14 days before catheter removal.

Referral and escalation. Urgent urology and surgical referral. Theatre without delay for peritonitis, instability or bowel injury.