6.3 Bladder & Urethral Trauma (High-Riding Prostate & Retrograde Urethrography)

6.3 Bladder & Urethral Trauma (High-Riding Prostate & Retrograde Urethrography)

Traumatic injuries to the lower urinary tract—comprising the bladder and urethra—frequently accompany pelvic ring disruptions and high-energy lower abdominal trauma. Approximately 15% to 20% of severe pelvic fractures are complicated by urethral or bladder tears.

Because missed lower urinary tract injuries lead to severe complications including urinary extravasation, retroperitoneal phlegmon, pelvic abscess, sepsis, urethral strictures, and permanent urinary incontinence or erectile dysfunction, Trauma Certified Registered Nurses (TCRNs) must master the classic clinical signs of urethral disruption, recognize absolute contraindications to catheterization, and understand the management differences between intraperitoneal and extraperitoneal bladder ruptures.

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Urethral Trauma & Clinical Assessment

The male urethra is divided into the posterior urethra (prostatic and membranous segments) and anterior urethra (bulbous and pendulous/penile segments). Female urethral trauma is rare due to its short length and mobility, but can occur with severe open pelvic fractures.

• Posterior Urethral Disruption: Most commonly caused by high-energy pelvic ring fractures (APC II/III, Vertical Shear). Shearing forces shear the prostate and bladder off the fixed urogenital diaphragm, transecting the membranous urethra.
• Anterior Urethral Disruption: Most commonly caused by "straddle" injuries (e.g., bicycle crossbar, fence, ladder fall) or direct blunt force to the perineum, causing crush injury of the bulbous urethra against the inferior pubic rami.

Classic Clinical Triad of Urethral Disruption

1. Blood at the Urethral Meatus: The single most sensitive clinical indicator of urethral injury, present in over 75% of cases.
2. Perineal / Scrotal / Labial Hematoma & Ecchymosis: Resulting from blood tracking beneath Buck's and Colles' fascia.
3. High-Riding or Non-Palpable Prostate: On Digital Rectal Examination (DRE), complete urethral transection allows the prostate to displace superiorly out of the pelvis due to disruption of the puboprostatic ligaments.

               [ CLASSIC TRIAD OF URETHRAL INJURY ]
    +---------------------------------------------------------+
    | 1. Blood at the Urethral Meatus                         |
    | 2. Perineal / Scrotal Ecchymosis or Hematoma            |
    | 3. High-Riding / Non-Palpable Prostate on DRE           |
    +---------------------------------------------------------+
                               ||
                               \/
    [ ABSOLUTE CONTRAINDICATION: DO NOT INSERT FOLEY CATHETER ]

🚫 ABSOLUTE NURSING CONTRAINDICATION: The presence of blood at the urethral meatus, perineal ecchymosis, or a high-riding prostate is an ABSOLUTE CONTRAINDICATION to inserting a standard transurethral (Foley) catheter.

Clinical Rationale: Attempting blind catheterization against a torn or disrupted urethra can convert a partial urethral tear into a complete 100% transection, create false urethral passages, introduce bacteria into a sterile retroperitoneal hematoma causing severe pelvic sepsis, and significantly increase the risk of permanent erectile dysfunction and stricture formation.

Diagnostic Gold Standard: Retrograde Urethrography (RUG)

Before any urethral catheterization is attempted in a patient with suspected urethral trauma, a Retrograde Urethrography (RUG) must be performed:

• Technique: A small 6–8 Fr catheter or balloon cannula is inserted 1 to 2 cm into the urethral meatus. The balloon is gently inflated with 1 to 2 mL of sterile water in the fossa navicularis to seal the orifice. 15 to 25 mL of radiopaque contrast is injected retrograde under fluoroscopic spot radiography.
• Interpretation: Extravasation of contrast outside the urethral lumen confirms urethral disruption. If the RUG demonstrates an intact urethra, standard Foley catheterization may safely proceed.
• Definitive Management: If urethral disruption is confirmed, a Suprapubic Catheter (SPC) is placed percutaneously or surgically under urological guidance to decompress the bladder, delaying definitive endoscopic or open urethral reconstruction for 3 to 6 months.

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Bladder Rupture: Intraperitoneal vs. Extraperitoneal

Bladder trauma occurs secondary to blunt abdominal impacts or pelvic fractures. Bladder ruptures are classified anatomically into intraperitoneal, extraperitoneal, or combined injuries.

Mechanism & Management Rationale

1. Intraperitoneal Rupture Management

Intraperitoneal tears occur at the bladder dome, which is the weakest structural region when distended with urine. When blunt pressure forces urine through the dome, urine pours into the peritoneal cavity.

Because urine causes severe chemical irritation, peritonitis, urinary autodialysis (causing electrolyte imbalances such as hyperkalemia and elevated BUN/creatinine), pelvic abscess, and sepsis, intraperitoneal bladder rupture will NOT heal spontaneously with catheter drainage alone. Emergency operative surgical repair is mandatory.

2. Extraperitoneal Rupture Management

Extraperitoneal tears occur at the base or anterior wall when bony spicules from pubic ramus fractures puncture the bladder wall. Urine leaks into the retroperitoneal loose connective tissues.

Because the leak remains strictly outside the peritoneal cavity, extraperitoneal ruptures heal spontaneously by secondary intention in > 85–90% of cases, provided the bladder is continuously decompressed with a large-bore (20–24 Fr) transurethral catheter for 10 to 14 days.

• Exceptions requiring surgical repair: Open pelvic fractures, bone fragments protruding into the bladder wall, bladder neck involvement, or co-existing intra-abdominal injuries requiring laparotomy.

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Diagnostic Modality for Bladder Injury: CT Cystography

Standard contrast CT of the abdomen and pelvis with intravenous contrast is INADEQUATE to rule out bladder rupture, missing up to 50% of injuries because IV contrast excreted from the kidneys does not distend the bladder sufficiently.

💡 DIAGNOSTIC MANDATE: CT CYSTOGRAPHY Evaluation of suspected bladder rupture requires a dedicated CT Cystogram with retrograde gravity filling:

1. A urinary catheter is placed (after confirming urethral integrity via RUG).
2. 300 to 350 mL of dilute radiopaque contrast is instilled into the bladder by gravity flow (never hand-injected under high pressure).
3. CT images are acquired with the bladder fully distended, followed by post-void or post-drainage imaging to detect contrast extravasation hidden behind a distended bladder.