Ruptur Buli

01Pathophysiology

The bladder is a hollow muscular organ that sits in the pelvis, protected by the bony pelvic ring when empty. As it fills with urine, the dome of the bladder rises above the pelvic brim and becomes an intra-abdominal organ, making it vulnerable to injury from blunt force. This anatomic transition is the single most important concept for understanding the two patterns of rupture.

Intraperitoneal rupture occurs when a forceful blow strikes a fully distended bladder. The dome, which is the weakest and most mobile part of the bladder wall, is also the only portion covered by peritoneum. A sudden rise in intravesical pressure (such as from a seatbelt compression or a direct kick to the lower abdomen) causes the dome to burst like an overfilled balloon. Urine then spills freely into the peritoneal cavity, mixing with bowel contents and triggering a chemical peritonitis. Over hours, the patient develops diffuse abdominal pain, guarding, and rigidity. Because the peritoneum is highly absorptive, urea and creatinine are reabsorbed into the bloodstream, producing a paradoxical rise in serum BUN and creatinine even though the kidneys are functioning normally. This is a classic exam finding: azotemia that does not match the clinical picture of renal failure.

Extraperitoneal rupture is far more common and is almost always associated with pelvic fractures. The mechanism involves direct laceration of the anterolateral bladder wall by a bony spicule from a fractured pubic ramus, or shearing of the bladder at its fascial attachments when the pelvic ring is disrupted. Urine leaks into the perivesical space (the space of Retzius) but is contained by the pelvic fascia. Because there is no peritoneal contamination, these patients do not develop peritonitis; instead, they present with perineal or scrotal swelling and localized suprapubic pain.

The clinical hallmark of both types is gross hematuria, which is present in over 95% of cases. Any trauma patient with pelvic fracture and gross hematuria should prompt immediate evaluation for bladder injury.

02Classification and Clinical Manifestation

The American Association for the Surgery of Trauma (AAST) also grades bladder injuries:

03Diagnostic Workup

The workup begins at the bedside. In any trauma patient with pelvic pain and gross hematuria, your clinical suspicion for bladder injury should be high. The first step, however, is not to rush to imaging of the bladder. You must first rule out urethral injury before placing a Foley catheter, because blind catheterization in the setting of a urethral tear can convert a partial disruption into a complete one.

Check for signs of urethral injury: blood at the urethral meatus, a high-riding or boggy prostate on rectal exam, or perineal butterfly hematoma. If any of these are present, perform a retrograde urethrogram (RUG) before catheterization. If the urethrogram is normal, proceed with catheter placement. This sequencing question is a favorite on exams.

Once a catheter is in place, the study of choice is CT cystography. This involves filling the bladder in a retrograde fashion with at least 300 to 350 mL of dilute contrast through the Foley catheter, then obtaining CT images. Adequate distension is critical; an under-filled bladder can produce a false-negative result because small tears are tamponaded by surrounding tissue and only leak when the bladder is stretched.

The pattern of contrast extravasation tells you the type of rupture:

• Intraperitoneal: Contrast flows freely into the peritoneal cavity, outlining loops of bowel, filling the paracolic gutters, and layering between mesenteric folds. This is described as contrast surrounding bowel loops.

• Extraperitoneal: Contrast is confined to the perivesical tissues, creating irregular, flame-shaped or starburst streaks in the space of Retzius, sometimes tracking along fascial planes into the thigh, scrotum, or anterior abdominal wall.

A standard contrast-enhanced CT of the abdomen and pelvis done for trauma (where contrast is given IV and excreted into the bladder passively) is not sufficient to rule out bladder rupture. The bladder is not adequately distended with passive filling alone. The exam must explicitly include retrograde filling with clamped drainage. This is one of the most tested distinctions.

04Management and Treatment

Priority in trauma management: Before addressing the bladder injury itself, the patient must be stabilized according to ATLS principles. Pelvic fracture with hemorrhage takes precedence: pelvic binder application, transfusion, and angiographic embolization or preperitoneal packing for hemodynamic instability are addressed first. Bladder repair is performed once the patient is stable enough for definitive surgery.

Extraperitoneal rupture is managed non-operatively in most cases. A large-bore Foley catheter (typically 18 to 22 French) is placed to provide continuous drainage for 10 to 14 days. The rationale is straightforward: with the bladder kept decompressed, the tear is no longer exposed to intravesical pressure, and the well-vascularized bladder wall heals on its own. Before catheter removal, a follow-up cystogram is obtained to confirm complete healing. Approximately 85% of extraperitoneal injuries heal with catheter drainage alone.

Surgical repair is indicated for extraperitoneal rupture only in selected situations: when bony fragments are embedded in the bladder wall, when the injury involves the bladder neck or trigone (risking ureteral orifice compromise), when there is a concurrent rectal or vaginal laceration requiring operative repair, or when the patient is already undergoing open pelvic fixation (the bladder can be repaired at the same time).

Intraperitoneal rupture always requires surgical exploration and repair. The procedure is performed via laparotomy. The peritoneal cavity is irrigated thoroughly to remove urine, which causes chemical peritonitis if left in contact with the serosa. The bladder tear is repaired in two layers using absorbable suture (typically polyglycolic acid). The peritoneal cavity is washed out, and a Foley catheter is left in place for 7 to 14 days postoperatively. A suprapubic catheter may be placed in addition for drainage.

Antibiotic coverage is provided to prevent urinary tract infection during the period of catheterization. A first-generation cephalosporin or fluoroquinolone is commonly used.

Combined injuries are treated as intraperitoneal ruptures: all patients go to the operating room for definitive repair.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on bladder rupture questions is by failing to distinguish the management of intraperitoneal versus extraperitoneal injuries. The vignette will describe a trauma patient with hematuria and a cystogram showing contrast extravasation. If contrast outlines bowel loops (intraperitoneal), the answer is surgery. If contrast is confined to the perivesical space in a flame-shaped or starburst pattern (extraperitoneal), the answer is Foley catheter drainage. Picking catheter drainage for an intraperitoneal rupture, or surgery for an uncomplicated extraperitoneal rupture, are both classic traps.

The second common mistake is ordering a standard CT abdomen/pelvis and assuming it rules out bladder injury. A CT performed with only intravenous contrast does not adequately distend the bladder. The question may describe a "CT scan" that is read as "no bladder injury." If the clinical picture still suggests rupture (persistent hematuria, inability to void, rising creatinine), the next best step is a dedicated CT cystogram with retrograde filling, not a repeat standard CT.

Third, never forget the sequencing rule: if blood is present at the urethral meatus, perform a retrograde urethrogram before placing a Foley catheter. The vignette may include a subtle mention of blood at the meatus or a high-riding prostate. If you skip the urethrogram and go straight to catheterization or cystography, you have chosen the wrong next step and risk converting a partial urethral tear into a complete one.

Finally, watch for the "rising creatinine" trap. A patient with intraperitoneal bladder rupture will develop elevated BUN and creatinine from peritoneal reabsorption of urine, not from renal failure. If the vignette shows a trauma patient with a normal-appearing kidney on CT but unexplained azotemia and peritoneal signs, think intraperitoneal bladder rupture. The core competency being tested here is pattern recognition: linking gross hematuria, a mechanism involving a full bladder or pelvic fracture, and contrast extravasation patterns to the correct type of rupture and its corresponding treatment.