# Bladder and Urethral Trauma

## Introduction

Bladder and urethral injuries represent important aspects of genitourinary trauma and are most frequently caused by blunt mechanisms associated with pelvic fractures or by penetrating injuries. Timely diagnosis is crucial because missed injuries can lead to severe complications such as sepsis, peritonitis, and long-term functional problems. The approach to evaluation and management varies considerably depending on whether the bladder rupture is intraperitoneal or extraperitoneal, as well as whether the urethral injury involves the anterior or posterior urethra.

## Bladder Trauma

### Anatomy and Mechanism

The bladder is primarily an extraperitoneal organ when empty, but its dome is covered by peritoneum and becomes intraperitoneal when distended. The majority of bladder injuries, accounting for 85-95%, result from blunt trauma, while penetrating trauma causes 5-15% of cases. Bladder injury is associated with pelvic fractures in about 5-10% of cases, where bony fragments can directly lacerate the bladder wall. A distended bladder is more vulnerable to rupture, making intoxicated patients with full bladders particularly at risk.

### Classification

#### Extraperitoneal Bladder Rupture (60-65%)

Extraperitoneal bladder ruptures typically occur in conjunction with pelvic fractures. The tear usually involves the anterolateral wall or the base near the bladder neck. On cystography, contrast extravasation is confined to the perivesical space and tracks along fascial planes, producing characteristic "flame-shaped" or "molar tooth" patterns. Management generally involves large-bore Foley catheter drainage for 10 to 14 days, with a repeat cystogram performed before catheter removal. Surgical intervention is reserved for cases with bone fragments inside the bladder, concurrent vaginal or rectal injuries, bladder neck injuries, or failure to resolve with catheter drainage alone.

#### Intraperitoneal Bladder Rupture (25-30%)

Intraperitoneal bladder ruptures usually result from blunt trauma to a distended bladder, where a sudden increase in intravesical pressure causes rupture at the bladder dome, the weakest point. Contrast extravasation on imaging outlines bowel loops, paracolic gutters, and spaces between pelvic organs. Surgical repair is mandatory for intraperitoneal ruptures, involving primary closure in two to three layers with absorbable sutures via laparotomy or laparoscopy. Delayed diagnosis can lead to peritonitis, urosepsis, and electrolyte disturbances due to urine reabsorption across the peritoneum, which mimics renal failure with elevated blood urea nitrogen and creatinine levels.

#### Combined Injuries (5-10%)

Some patients sustain both intra- and extraperitoneal bladder injuries. These are managed by surgically repairing the intraperitoneal component while providing catheter drainage for the extraperitoneal portion.

| Type | Frequency | Mechanism | Cystogram Finding | Management |
|---|---|---|---|---|
| Extraperitoneal | 60-65% | Pelvic fracture; anterolateral wall/base tear | Flame-shaped perivesical extravasation | Catheter drainage 10-14 days |
| Intraperitoneal | 25-30% | Blunt trauma to distended bladder; dome rupture | Contrast outlines bowel loops/paracolic gutters | Mandatory surgical repair |
| Combined | 5-10% | Both mechanisms | Both patterns | Surgical repair (IP) + catheter (EP) |

### Diagnosis

Gross hematuria is present in over 95% of bladder injury cases and should raise suspicion in any patient with a pelvic fracture. The gold standard diagnostic test is the CT cystogram, which requires retrograde filling of the bladder with approximately 350 mL of dilute contrast via a Foley catheter before imaging. Passive filling from intravenous contrast is insufficient and can miss up to 36% of injuries. Conventional retrograde cystography involves filling the bladder with 300 to 400 mL of contrast and obtaining anteroposterior, oblique, and post-drainage films. The post-drainage film is critical because it can reveal posterior extravasation that may be obscured by a fully distended bladder. Indications for cystography include gross hematuria with pelvic fracture, penetrating trauma near the bladder, or clinical suspicion of rupture.

<image>CT cystogram images comparing intraperitoneal bladder rupture (contrast outlining bowel loops and collecting in paracolic gutters from a dome rupture) and extraperitoneal bladder rupture (flame-shaped contrast extravasation tracking along perivesical fascial planes from an anterolateral wall injury), with labeled anatomic landmarks and pelvic fracture fragments visible</image>

### Surgical Repair Technique

Surgical repair is performed via a midline laparotomy or laparoscopic approach. The laceration is identified and devitalized edges are debrided. Closure is achieved with a two- or three-layer watertight technique using absorbable sutures such as 3-0 Vicryl. It is important to assess for involvement of the ureteral orifices; if the injury is near these structures, ureteral patency should be confirmed using intravenous indigo carmine or fluorescein. A large-bore Foley catheter is placed, and a suprapubic tube may be added optionally. A repeat cystogram is performed 10 to 14 days postoperatively before catheter removal.

## Urethral Trauma

### Posterior Urethral Injury (Pelvic Fracture Urethral Injury — PFUI)

Posterior urethral injuries occur due to disruption at the membranous urethra caused by shearing forces from pelvic ring fractures, especially pubic symphysis diastasis or bilateral rami fractures. These injuries occur in 5-10% of pelvic fractures and affect 10-20% of males with such fractures. The pelvic hematoma displaces the prostate superiorly and posteriorly.

Clinically, blood at the urethral meatus is the cardinal sign and is present in 37-93% of cases. A high-riding prostate on digital rectal exam is a classic finding but is often unreliable or difficult to assess. Patients may be unable to void despite a palpable bladder, and perineal ecchymosis in a butterfly pattern may be observed. Importantly, a urethral catheter should never be passed if PFUI is suspected; a retrograde urethrogram (RUG) must be performed first.

Diagnosis is confirmed with a retrograde urethrogram, which involves injecting 20-30 mL of water-soluble contrast through the urethral meatus using a catheter-tip syringe while obtaining an oblique radiograph. Findings include contrast extravasation at the membranous urethra, which may show complete disruption if no contrast reaches the bladder or partial tear if some contrast passes proximally.

Management in the acute phase involves placement of a suprapubic catheter for urinary diversion and treatment of associated injuries. Primary realignment, which consists of early endoscopic realignment over a catheter within 7 to 14 days, can reduce the severity of subsequent strictures but does not prevent them. This approach is controversial because aggressive realignment may increase the risk of incontinence and erectile dysfunction. Definitive repair is usually delayed until about three months after injury when the hematoma has resolved. Delayed urethroplasty is performed via a perineal approach, excising the fibrotic segment and performing a bulboprostatic anastomosis. Success rates for continence range from 85-95%, while erectile dysfunction occurs in 20-55% of cases, primarily related to the original injury rather than the surgery. Techniques to bridge the urethral gap include corporal splitting, inferior pubectomy, and supracrural rerouting.

### Anterior Urethral Injury

Anterior urethral injuries commonly result from straddle injuries, where a fall astride a hard object such as a bicycle crossbar, fence, or machinery compresses the bulbar urethra against the inferior pubic ramus. Penile fractures may involve the penile urethra in 10-20% of cases. Penetrating trauma such as gunshot or stab wounds and instrumentation injuries from traumatic catheterization or endoscopic procedures are other causes.

Anterior urethral injuries are classified as contusions, partial disruptions, or complete disruptions. Contusions present with blood at the meatus but no extravasation on RUG and are managed with observation and gentle catheterization. Partial disruptions show contrast extravasation with some contrast reaching the bladder and are treated with catheter stenting for 2-3 weeks. Complete disruptions demonstrate no contrast reaching the bladder and require suprapubic catheter placement followed by delayed urethroplasty.

The integrity of Buck's fascia influences the pattern of extravasation. If Buck's fascia remains intact, blood and urine are confined to the penile shaft, producing a sleeve-shaped swelling. If Buck's fascia is disrupted, blood and urine spread into the perineum, scrotum, and anterior abdominal wall, limited by Colles' fascia (superficial perineal fascia). This results in the classic butterfly-shaped perineal ecchymosis and scrotal swelling.

<image>Anatomic diagram showing extravasation patterns in anterior urethral injury: (1) injury contained within intact Buck's fascia with penile shaft swelling only, and (2) injury with disrupted Buck's fascia showing fluid tracking into the perineum (Colles' fascia), scrotum (dartos fascia), and anterior abdominal wall (Scarpa's fascia), with fascial boundaries labeled and color-coded</image>

## Special Considerations

Female urethral injuries are rare due to the short and mobile nature of the female urethra. When they do occur, they are often associated with pelvic fractures and vaginal lacerations. Blood at the vaginal introitus in the setting of a pelvic fracture should raise suspicion for urethral injury. Primary surgical repair with catheter stenting is preferred over delayed management in these cases.

In children, bladder injuries carry a higher risk because the bladder is more of an abdominal organ. There is a lower threshold for surgical repair in pediatric patients, and even extraperitoneal injuries may warrant surgery if associated with pelvic fractures requiring internal fixation.

Iatrogenic bladder injuries most commonly occur during gynecologic procedures such as hysterectomy, cesarean section, and hernia repair. Intraoperative recognition and immediate repair yield the best outcomes. Repair involves a two-layer closure and catheter drainage for 7 to 14 days.

<image>Retrograde urethrogram radiograph showing a complete posterior urethral disruption at the membranous urethra with contrast extravasation into the perivesical space, no contrast reaching the bladder, and superior displacement of the bladder/prostate by pelvic hematoma, with pubic symphysis diastasis and bilateral superior rami fractures visible</image>

## Key Clinical Pearls

When blood is present at the urethral meatus, a urethral catheter should never be passed until a retrograde urethrogram has excluded urethral injury. CT cystography requires active retrograde filling of the bladder with approximately 350 mL of contrast; passive filling from intravenous contrast is unreliable and can miss injuries. Intraperitoneal bladder ruptures always require surgical repair, whereas extraperitoneal ruptures are usually managed with catheter drainage alone. The post-drainage film on conventional cystography is essential because it reveals posterior extravasation that may be hidden by the contrast-filled bladder. In pelvic fracture urethral injury, placing a suprapubic catheter acutely and planning delayed urethroplasty at three months yields the best long-term outcomes for continence and stricture prevention. Erectile dysfunction following PFUI is primarily related to the original injury, involving cavernous nerve and vascular damage from the pelvic fracture, rather than the subsequent surgical repair.

## References

1. Morey AF, Brandes S, Dugi DD, et al. Urotrauma: AUA guideline. *J Urol*. 2014;192(2):327-335.  
2. Gomez RG, Ceballos L, Coburn M, et al. Consensus statement on bladder injuries. *BJU Int*. 2004;94(1):27-32.  
3. Chapple C, Barbagli G, Jordan G, et al. Consensus statement on urethral trauma. *BJU Int*. 2004;93(9):1195-1202.  
4. Bjurlin MA, Goble SM, Fantus RJ, et al. Outcomes in geriatric genitourinary trauma. *J Am Coll Surg*. 2011;213(3):415-421.