Genitourinary Trauma Assessment
Systematic evaluation of the GU system begins with the primary and secondary trauma surveys. Because GU injuries are frequently occult and hematuria is an unreliable marker of injury severity, a protocol-driven approach — guided by mechanism, hemodynamic status, and associated injuries — determines appropriate imaging and intervention.
Initial Evaluation
History and Mechanism
Key details that raise suspicion for GU injury:[1][2]
- Rapid deceleration (MVA, fall from height) → renal pedicle injury, UPJ avulsion
- Direct flank blow → renal laceration or contusion
- Pelvic ring fracture → bladder rupture, posterior urethral injury
- Straddle impact (fall onto crossbar, saddle) → anterior (bulbar) urethral injury
- Penetrating trajectory toward flank, pelvis, or perineum → any GU organ depending on path
- Seatbelt sign across lower abdomen → bladder or mesenteric injury
Physical Examination
| Finding | Implication |
|---|---|
| Flank ecchymosis / flank mass | Perirenal hematoma; renal injury |
| Blood at the urethral meatus | Urethral injury — do not place Foley until urethrogram performed |
| Perineal / scrotal ecchymosis (butterfly hematoma) | Bulbar urethral injury with Buck's fascia disruption |
| Inability to void with pelvic fracture | Posterior urethral injury |
| Abdominal distension, ileus | Intraperitoneal bladder rupture (urinary ascites) |
| Vaginal bleeding after pelvic trauma | Female urethral or vaginal injury |
:::warning Blood at the Meatus Never insert a urethral catheter if blood at the meatus is present without first performing a retrograde urethrogram (RUG) to exclude urethral injury. Blind catheterization can convert a partial urethral tear into a complete disruption.[1] :::
Urinalysis and Hematuria
Urine dipstick or microscopy is the initial screening step:
| Finding | Action |
|---|---|
| Gross hematuria | Imaging indicated regardless of hemodynamic status; CT with IV contrast in stable patients |
| Microscopic hematuria + hypotension (SBP <90 mmHg at any point) | CT with IV contrast (triple-phase if renal injury suspected) |
| Microscopic hematuria, hemodynamically stable | Assess mechanism; image if high-energy deceleration, penetrating injury, or pediatric patient |
| No hematuria, penetrating trajectory toward GU | Image regardless — hematuria is absent in up to 55% of ureteral injuries |
| No hematuria, low-energy blunt mechanism | Imaging generally not indicated |
:::note Pediatric Exception Children have less perirenal fat and more pliable ribs, making the kidney more vulnerable. Any degree of hematuria in a pediatric trauma patient warrants CT imaging regardless of hemodynamic status.[2] :::
Indications for Emergent Intervention
The following findings mandate immediate intervention — imaging should not delay operative or angiographic management in hemodynamically unstable patients:[1][3]
- Hemodynamic instability despite resuscitation with suspected GU source (renal vascular injury, high-grade renal laceration)
- Expanding or pulsatile retroperitoneal hematoma found at laparotomy
- Peritonitis with suspected bladder or ureteral injury (urinary ascites)
- Penile amputation or complex degloving requiring emergent surgical control
- Fournier's gangrene with systemic sepsis
:::note Retroperitoneal Hematoma at Laparotomy Zone 1 (central): Explore — aorta/IVC injury. Zone 2 (perinephric/lateral): Explore if pulsatile or expanding; otherwise observe in blunt trauma. Zone 3 (pelvic): Do not explore in blunt trauma — pack and obtain angiography.[3] :::
Imaging Overview
Imaging selection follows hemodynamic stability and suspected injury. Full protocols are covered in the organ-specific pages; a summary is provided here.
:::note Cross-Reference Detailed imaging modalities, contrast protocols, and interpretation are covered in the Imaging page of the Evaluation & Workup section. :::
CT Abdomen and Pelvis with IV Contrast
The primary imaging modality for stable trauma patients with suspected GU injury. Protocol considerations:[1][4]
| Phase | Timing After Contrast | Purpose |
|---|---|---|
| Arterial (~25–30 sec) | Early | Renal vascular injury, active hemorrhage detection |
| Portal venous (~70 sec) | Standard trauma CT | Parenchymal injuries, solid organ lacerations |
| Delayed / excretory (~5–10 min) | Added when urinary injury suspected | Contrast extravasation from collecting system, ureter, or bladder |
The delayed phase is essential for diagnosing collecting system injuries, ureteral lacerations, and evaluating urinary extravasation. It should be obtained whenever there is gross hematuria, penetrating injury, or mechanism suggesting ureteral or bladder involvement.
Retrograde Urethrogram (RUG)
Indicated before Foley catheter placement when urethral injury is suspected:[1]
- Blood at urethral meatus
- Perineal / scrotal ecchymosis
- Pelvic fracture with inability to void
- Mechanism consistent with straddle injury
Technique: Patient supine or slight oblique; inject 15–20 mL of contrast (iothalamate or iohexol) under fluoroscopy via a 12 Fr Foley balloon inflated to 2–3 mL in the fossa navicularis; assess for extravasation. In the pelvic fracture patient, obtain CT before RUG to avoid radiation and positioning risk.
CT Cystography
Indicated for suspected bladder injury when CT of the abdomen and pelvis is already being performed. Passive filling (clamping the Foley during CT) is insufficient — retrograde filling to ≥300 mL is required. See Bladder Trauma for full protocol.
Scrotal Ultrasound
Indicated for blunt scrotal trauma when physical exam is equivocal. Tunica albuginea disruption (heterogeneous testicular echo, loss of normal contour) is an indication for operative exploration. See Genital & Scrotal Trauma.
Urinary Diversion Decisions
When urethral injury is confirmed or suspected prior to definitive diagnosis:[1]
| Situation | Preferred Diversion |
|---|---|
| Confirmed or suspected urethral injury | Suprapubic tube (SPT) — do not attempt blind urethral catheterization |
| Bladder injury requiring prolonged catheterization | Large-bore urethral Foley (≥18 Fr); SPT as adjunct for complex repairs |
| Ureteral injury with delayed diagnosis | Retrograde stenting; percutaneous nephrostomy if stenting fails |
| Intraoperative ureteral injury, damage control | Ureteral ligation + nephrostomy; cutaneous ureterostomy |
Documentation and Workup Completeness
Every trauma patient with a suspected GU injury should have documentation of:[2]
- Mechanism and energy level
- Presence, degree, and laterality of hematuria
- Hemodynamic parameters on arrival and trajectory
- Physical exam findings (meatus, perineum, flank, abdomen)
- Imaging obtained and findings
- Urologic consultation (or documentation of transfer plan if unavailable)
- Urinary diversion decision and catheterization strategy
References
1. American College of Surgeons Trauma Quality Programs. ACS TQP Best Practices Guidelines: Management of Genitourinary Injuries. Chicago, IL; August 2025. Available at: facs.org/cot
2. Morey AF, Broghammer JA, Hollowell CMP, McKibben MJ, Souter L. Urotrauma Guideline 2020: AUA Guideline. J Urol. 2021;205(1):30–35. PMID 33064586
3. Feliciano DV, Mattox KL, Moore EE, eds. Trauma. 9th ed. McGraw-Hill; 2020. Chapter on retroperitoneal hematoma and zone management.
4. Santucci RA, Wessells H, Bartsch G, et al. Evaluation and management of renal injuries: Consensus statement of the renal trauma subcommittee. BJU Int. 2004;93(7):937–954. PMID 15142141