Ruptur Uretra

01Pathophysiology

The male urethra is anatomically divided into anterior and posterior segments by the urogenital diaphragm (perineal membrane). This anatomical landmark is the single most important concept for understanding urethral trauma because the mechanism, clinical presentation, pattern of extravasation, and management all differ depending on which segment is injured.

Posterior urethral injuries involve the prostatic and membranous urethra. These are almost exclusively associated with pelvic fractures, particularly fractures involving the pubic rami or disruption of the pelvic ring. The mechanism is a shearing force: the prostate, fixed superiorly by the puboprostatic ligaments, is displaced relative to the membranous urethra, which is fixed at the urogenital diaphragm. This results in a stretch injury or complete transection at the prostatomembranous junction. The Trauma Urogenital IAUI 2022 guideline emphasizes that posterior urethral injury occurs in roughly 5 to 10 percent of pelvic fracture cases, and the clinician must have a high index of suspicion in any patient with a pelvic ring disruption.

Anterior urethral injuries involve the bulbar and penile urethra. The classic mechanism is a straddle injury, where the perineum strikes a hard object (a bicycle crossbar, a fence, or a fall). The bulbar urethra is compressed against the inferior aspect of the pubic symphysis, leading to contusion or rupture. In a straddle-type injury, the bulbar urethra is the most vulnerable segment because it is the least mobile portion of the anterior urethra.

The pattern of urinary extravasation follows fascial planes and is directly testable:

In anterior urethral rupture with an intact Buck's fascia, urine and blood track along the penile shaft deep to Buck's fascia. If Buck's fascia is disrupted, extravasation spreads into the perineum within Colles' fascia, producing the characteristic "butterfly" ecchymosis on the perineum. This extravasation is limited superiorly by Colles' fascia attachment to the perineal body posteriorly and the coracoabdominal fascia (Scarpa's fascia) anteriorly, meaning fluid can spread to the scrotum, perineum, penis, and anterior abdominal wall, but not to the thighs or buttocks.

In posterior urethral rupture, extravasation occurs above the urogenital diaphragm into the pelvic extraperitoneal space. Urine tracks into the retropubic (Retzius) space. This is why posterior injuries do not produce visible perineal ecchymosis unless the urogenital diaphragm is also disrupted.

Understanding this fascial anatomy explains every clinical finding: why anterior injuries cause perineal swelling while posterior injuries do not, and why posterior injuries present with a high-riding prostate (the bladder and prostate are displaced superiorly by the expanding pelvic hematoma).

02Classification and Clinical Manifestation

The Trauma Urogenital IAUI 2022 guideline references the widely used classification system that categorizes urethral injury by anatomical location and severity. The most commonly tested system in clinical examinations is the AAST (American Association for the Surgery of Trauma) urethral injury scale, supplemented by radiographic classification based on retrograde urethrography findings:

AAST Urethral Injury Grading

Clinical Manifestation by Location

Posterior Urethral Injury Subclassification (Colapinto and McCallum)

03Diagnostic Workup

The diagnostic sequence for urethral trauma is one of the most testable algorithms in urology, and the Trauma Urogenital IAUI 2022 guideline provides a clear approach.

Step 1: Clinical Suspicion. In any trauma patient, particularly those with pelvic fractures or perineal injuries, the clinician must actively look for signs of urethral injury before any attempt at catheterization. The triad of blood at the urethral meatus, inability to void, and perineal ecchymosis should halt any catheterization attempt. In posterior injuries, a high-riding prostate on DRE (meaning the prostate is displaced superiorly and cannot be palpated in its normal position) is an additional finding, though its sensitivity is debated and its absence does not exclude posterior urethral injury.

Step 2: Retrograde Urethrography (RUG). This is the best initial diagnostic test and simultaneously the most accurate test. There is no distinction between screening and confirmatory testing here, because the RUG serves both roles. The procedure involves inserting a small catheter (8 Fr feeding tube or a Foley catheter with the balloon inflated in the fossa navicularis to create a seal) into the urethral meatus and injecting 20 to 30 mL of water-soluble contrast under fluoroscopy or with a plain film. The study is read as follows:

• Normal urethrogram: contrast flows freely into the bladder without extravasation. This effectively rules out urethral disruption.

• Partial disruption: contrast extravasates at the injury site, BUT some contrast is also seen entering the bladder. This indicates continuity is maintained.

• Complete disruption: contrast extravasates, and NO contrast reaches the bladder. The two urethral ends are separated.

Step 3: Evaluate for associated injuries. According to the Trauma Urogenital IAUI 2022 guideline, posterior urethral injuries warrant evaluation for bladder injury (present in 10 to 20 percent of cases). A CT cystogram or conventional cystography is performed. In the polytrauma patient already undergoing CT for other reasons, delayed CT cystourethrography with retrograde bladder filling can be integrated into the workup.

Critical exam principle: never attempt urethral catheterization when urethral injury is suspected. Blind catheterization risks converting a partial tear into a complete disruption, introducing infection, and creating false passages. The RUG must be done first. The one exception in practice: if a gentle, single attempt at catheter passage succeeds without resistance, some guidelines accept this, but the safest and most testable answer is always "RUG before catheterization."

04Management and Treatment

Acute Stabilization

The first priority in urethral trauma, as outlined by the Trauma Urogenital IAUI 2022 guideline, is urinary diversion and management of associated life-threatening injuries. In a polytrauma patient with a posterior urethral disruption:

1. Hemodynamic stabilization takes priority. Pelvic fractures can cause life-threatening hemorrhage requiring pelvic binders, angiographic embolization, or preperitoneal pelvic packing.

2. Suprapubic cystostomy is placed for urinary drainage. This is a percutaneous procedure using a trocar or Seldinger technique, inserting a suprapubic catheter through the anterior abdominal wall directly into the distended bladder. The bladder must be distended (confirmed by ultrasound) before insertion.

3. Do not attempt primary realignment or open repair in the acute setting of a hemodynamically unstable patient with a posterior urethral disruption. Entering the pelvic hematoma risks uncontrollable hemorrhage.

Partial Tears (Anterior or Posterior)

If the RUG shows partial disruption (contrast reaches the bladder), a urethral catheter may be gently passed over a guidewire under fluoroscopic guidance or a small catheter (14 to 16 Fr) can be placed to serve as a stent. The catheter remains in place for 2 to 3 weeks (anterior) or 4 to 6 weeks (posterior). A follow-up RUG or voiding cystourethrogram (VCUG) is performed before catheter removal to confirm healing. If catheter placement fails, a suprapubic cystostomy is the fallback.

Complete Posterior Urethral Disruption

The management philosophy endorsed by the Trauma Urogenital IAUI 2022 guideline involves two phases:

• Acute phase: suprapubic cystostomy and watchful waiting. The rationale is that the pelvic hematoma needs 3 months to fully resorb, and operating in a fresh hematoma field increases the risk of bleeding, infection, incontinence, and erectile dysfunction.

• Definitive phase: delayed primary anastomotic urethroplasty at approximately 3 months. This involves excision of the fibrotic scar tissue at the disruption site and reanastomosis of the healthy urethral ends. Success rates exceed 90 percent in experienced hands. Before surgery, a combined antegrade (through the suprapubic tract) and retrograde urethrogram is performed to determine the gap length between the two urethral ends, which guides the surgical approach.

An alternative approach in selected hemodynamically stable patients is early endoscopic primary realignment, performed within the first 7 to 14 days. A catheter is passed across the disruption site under combined cystoscopic and fluoroscopic guidance (using both antegrade through a suprapubic tract and retrograde approaches). This is not a repair, but rather an alignment of the urethral ends over a catheter to promote healing and potentially reduce the stricture rate. The Trauma Urogenital IAUI 2022 guideline notes that early realignment may reduce the need for subsequent open urethroplasty, though it does not eliminate the risk of stricture formation.

Complete Anterior Urethral Disruption

Acute management is suprapubic cystostomy. Definitive repair is delayed anastomotic urethroplasty at 3 months, similar in principle to posterior injuries. The surgical approach for anterior injuries is perineal, and the procedure involves excision of the damaged segment and spatulated end-to-end anastomosis. For defects longer than 2 cm where tension-free primary anastomosis is not possible, a buccal mucosa graft urethroplasty or staged repair is performed.

Contraindications and Special Considerations

• Rectal injury concurrent with posterior urethral disruption: requires fecal diversion (colostomy) in addition to suprapubic cystostomy to prevent contamination.

• Female urethral injury: rare due to the short female urethra. When it occurs (typically in pelvic fractures), primary surgical repair is recommended early because delayed repair in females has poorer outcomes compared to males.

• Pediatric patients: the same principles apply, but surgeons are more conservative with timing, and the smaller anatomy demands careful technique.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on urethral trauma questions is by selecting "place a Foley catheter" as the next best step in a patient with blood at the meatus. This is the classic trap. The vignette will describe a trauma patient, possibly with a pelvic fracture, and note blood at the meatus. The answer choices will include catheterization, and many examinees pick it reflexively because urinary diversion sounds urgent. The correct answer is retrograde urethrography first. Blind catheterization risks worsening the injury, creating a false passage, and introducing infection.

A second common trap involves confusing anterior and posterior urethral injuries based on the mechanism. Students sometimes assign the wrong management because they misidentify the injury location. The rule is simple: pelvic fracture equals posterior; straddle injury equals anterior. The physical exam and extravasation patterns follow directly from the anatomy.

A third testing angle involves the high-riding prostate. This finding on DRE suggests posterior urethral disruption (the prostate is displaced upward by the expanding pelvic hematoma). However, its absence does not rule out posterior injury. The exam will occasionally present a posterior injury case without a high-riding prostate to test whether you still order a RUG based on the other signs (blood at meatus, pelvic fracture).

The core competency being tested is the ability to recognize the clinical triad of urethral injury (blood at meatus, inability to void, perineal or pelvic findings), correctly sequence the diagnostic workup (RUG before catheter), and choose the appropriate management based on injury location and completeness (partial vs. complete, anterior vs. posterior). The Trauma Urogenital IAUI 2022 guideline reinforces this approach: clinical suspicion, RUG for confirmation and classification, suprapubic cystostomy for diversion in complete injuries, and delayed urethroplasty as the definitive repair.