Management of Genitourinary Trauma

Evaluation of urological trauma:

Trauma to the genitourinary system usually occurs as part of a multisystem trauma rather than as an isolated presentation. Injury to organs of the genitourinary system should be suspected based on the mechanism and the anatomic location of the trauma. The kidneys, ureters, and bladder are well protected within the retroperitoneum, making them relatively less prone to injury. Therefore, urological traumas are relatively rare, comprising about 10% of total abdominal traumas.

Initial exam for genitourinary trauma:

1. Mechanism of injury: 
   • Blunt trauma: e.g. Collisions, motor vehicle accidents, fall
   • Penetrating Trauma: e.g.  gunshot wound, stab wound, impalement
   • Blast trauma: e.g. bomb explosion. Blast trauma often present with blunt and penetrating trauma
2. Differential diagnosis:
   • Injured organs: kidney, ureter, bladder, anterior and posterior urethra, and genitalia
   • Injury type: contusion, laceration, transection, avulsion, amputation, burn
3. Physical Exam:
   • Initial exam should involve standardized primary trauma survey
   • Focused physical exam for genitourinary trauma should include chest, flank, abdomen, genitalia and rectum:
     • Clues for injuries to kidney and ureter: rapid deceleration, blow to flank, rib fracture, flank ecchymosis, penetrating injury in abdomen flank or lower chest
     • Clues for injuries to bladder or urethra: unstable pelvis, ecchymosis of genitalia, blood at the tip of penis, gross hematuria. Inability to urinate and palpable bladder can occur when urethra is completely disrupted.  
     • Clues for injury to the male genitalia: Scrotal swelling, ecchymosis, or pain are linked with testicular injury. Penile injuries are usually self-evident based on exam.

Diagnostic studies for suspected genitourinary trauma:

1. Labs: Urinalysis (microscopic hematuria raises the concern for injury to urinary tract.); Creatinine/BUN; Hemoglobin/Hematocrit
2. Imaging studies: the individual modalities of imaging listed below should be performed when injuries to the respective organs were suspected based on history and exam.
   • Renal injuries:
     • Cross sectional imaging (i.e. contrast enhanced abdominal and pelvic CT with immediate and delayed phase)
       • Indications: high likelihood of renal injury from traumatic mechanism, blunt trauma patients with gross hematuria, blunt trauma patients with microscopic hematuria and SBP <90 at presentation.
       • All pediatric patients with more than 50 RBC/ high power field should receive CT with IV contrast
   • Ureteral injuries:
     • Cross sectional imaging with 10-minute delay after IV contrast administration (CT urogram)
       • Indicated for stable patients at risk for ureteral injury based on history and exam  
   • Bladder injuries:
     • Retrograde cystogram in the form of plain film or CT. A minimum of 300 mL of dilute water-soluble contrast should be instilled before imaging is obtained.
       • Absolute indication for imaging is gross hematuria with pelvic fracture. (29% will have bladder injury)
       • The injury being extraperitoneal or intraperitoneal determines the modality of management
   • Urethral injuries:
     • Retrograde urethrogram should be performed prior to attempted catheter placement if urethral injury is suspected. (blood at urethral meatus, unable to void with distended bladder)
   • Genital injuries:
     • Scrotal ultrasound should be performed for suspected testicular injury

Management of Genitourinary trauma:

Hemodynamic stabilization should be the first priority in all injured patients. Genitourinary trauma often presents as a part of multisystem trauma. Once the surgeon has a decent understanding of the extent of all injuries sustained by the patient, priority in management should be given to immediately life-threatening injuries.

1. Renal Trauma
   • National series showed 90% of renal trauma does not require intervention. Nonoperative management should be pursued for most renal injuries in the stable patient.  Grade I-III traumas rarely requires intervention, though intervention is more commonly needed in grade IV and V injuries. Initial observation is appropriate even for high grade renal injuries in the stable patient, as this strategy is most likely to preserve the kidney.
   • Hemodynamically unstable patient who does not respond to resuscitation should receive prompt abdominal exploration or angioembolization. The decision for renal exploration can be made intraoperatively if no imaging study was available preoperatively. Absolute indications for intervention include 1) expanding or pulsatile renal hematoma, 2) suspected renal vascular pedicle avulsion, 3) ureteropelvic junction avulsion. Relative indications include 1) persistent urine extravasation (higher complication rate if observation only, but close observation can be pursued), 2) renal injury with colon/pancreatic injury, 3) arterial thrombosis 4) urinary extravasation from parenchymal injury.
   • Surgical exploration should be performed via transabdominal approach which allows simultaneous inspection of other abdominal organs. Early vascular control can prevent substantial blood loss when the retroperitoneum is explored. Renal vessels can be isolated before exploration of the retroperitoneum by incising the peritoneum overlying the aorta medial to the inferior mesenteric vein.  With cephalad dissection, the renal artery and vein can be identified and clamped. Then, colon can be reflected for exposure of the kidney and renal hilum. If patient is unstable, prompt nephrectomy should be performed. For major renovascular injuries, prompt nephrectomy should be performed if injury is unilateral. In bilateral injuries, revascularization should be attempted. For renal parenchymal injuries, primary repair should be attempted in a stable patient. This would entail: debridement of nonviable tissue, hemostasis, water-tight closure of collecting system with absorbable sutures, and re-approximation of parenchymal defect. Omental pedicle flap, Gerota fascial flaps, and absorbable gelatin sponge can be used to aid in parenchymal repair. Drain placement should be considered.
   • Persistent urine extravasation can cause urinoma, sometimes perinephric infection, and rarely renal loss. Most urinoma resolve spontaneously and can be managed with empiric antibiotics. If it persists, internal ureteral stents with potential percutaneous drainage of urinoma or percutaneous nephrostomy can usually resolve this complication. Long term follow-up for renal function and blood pressure management are prudent for patients recovering from renal trauma.  
2. Ureteral Trauma
   • Ureteral trauma is rarely life threatening. The ureter is well protected by surrounding Musculo-fascial tissue and vertebral column, and 90% or ureteral injuries are associated with other organ injury. If possible, exploration and repair of injured ureter should be performed at the same time of initial laparotomy. Delayed repair can lead to urinoma, fistula, ureteral obstruction, and renal failure. The management of ureteral injury depends on the length and location of defect.
     • If immediate repair is impossible when the ureteral injury is too extensive or patient is hemodynamically unstable, ureter can be ligated and repair can be delayed with placement of a temporary nephrostomy tube.
     • Limited ureteral contusion should be managed with ureteral stenting.
     • Short proximal and middle ureteral defects can be repaired with direct ureteroureterostomy.  This entails: ureteral mobilization, debridement of injury and spatulation of margins, stent placement, and approximation of ureters with absorbable suture (typically 4-0).  In more extensive injuries, nephrectomy is an option if the ureter cannot be reconstructed.  More complex reconstruction (ileal interposition, buccal graft ureteroplasty, autotransplantation) is only performed in a delayed setting after recovery from initial injury. 
     • Distal ureteral injuries of any length are preferably repaired with ureteral reimplantation, which can be performed directly into the bladder or with mobilization of the bladder and fixation of the bladder to ipsilateral psoas tendon (“psoas hitch”). The ureter should be mobilized while preserving vascular supply and spatulated to allow for a widely patent anastomosis, with placement of ureteral stent and foley catheter to facilitate healing.

3. Bladder Trauma:
   • Up to 95% of traumatic bladder injures co-exist with pelvic fracture while only a small percentage (2-11%) of pelvic fractures are associated with concomitant bladder injury.
     • Uncomplicated extraperitoneal bladder rupture from blunt trauma is managed conservatively with foley catheter drainage.  Cystogram will demonstrate contrast extravasation limited to the extraperitoneal space (no bowel outlined by contrast; “flame” appearance limited to pelvis). Cystography is recommended before catheter removal, usually 2 weeks after injury. More time can be given for healing if initial cystography shows continuous leakage. Antibiotics should be given for at least 1 week as prophylaxis for pelvic hematoma.  
     • Open repair with absorbable suture can be considered if patient is undergoing simultaneous laparotomy for other abdominal injuries or orthopedic fixation of pelvic fracture (prevent hardware infection). Open repair should also be performed in the setting of a complicated extraperitoneal bladder injury (concurrent rectal or vaginal injury, bone fragments in bladder, or poor foley catheter drainage due to blood clots).  Repair should be performed via an abdominal approach using fine absorbable suture, ideally in two layers.
     • Intraperitoneal bladder rupture from blunt trauma or any penetrating trauma should be managed with timely surgical repair.  Cystogram will demonstrate contrast extravasation into the peritoneal space, outlining bowel and possibly extending up to diaphragm. During surgical exploration, attention is needed to confirm if bilateral ureteral orifices are intact with clear urine efflux. If ureteral orifice is injured, reimplantation and ureteral stent placement along with placement of peri-vesical drainage is recommended. Repair of bladder injury is achieved with 2 layers of fine absorbable suture.
4. Urethral Trauma:

3. Posterior Urethral Trauma: Typically coexist with pelvic fracture at bulbomembranous junction. Incomplete urethral tears should be managed with a foley catheter, as no evidence suggests that foley catheter insertion could aggravate the tear. In more extensive injuries, prompt suprapubic cystostomy is recommended to facilitate bladder drainage.  Delayed reconstruction is the standard of care and should be performed by a urologist with expertise in urologic reconstruction, a minimum of 3 months after initial trauma.
4. Anterior Urethral Trauma: Often anterior urethral trauma occurs at bulbar urethra after straddle injury. Suprapubic cystostomy is usually performed for significant injury, while realignment over foley catheter can be considered for injuries of smaller magnitude. For penetrating injuries such as low-velocity gunshot wound or stab wound with minimal tissue loss, immediate surgical exploration and primary repair are indicated. For extensive tissue loss, initial urinary diversion and delayed anastomotic urethroplasty would be the surgery of choice. Typically, 1.5 to 2 cm scar tissue can be completely excised with urethra mobilized and re-anastomosed in a tension free fashion at more than 95% success rate.
5. Genital Trauma:
   • Penetrating penile injuries: Perform retrograde urethrography as most will involve urethral injuries. These require urgent surgical exploration, copious irrigation, excision of foreign body, antibiotic prophylaxis, and closure.  Repair urethral injury according to principles above.
   • Penile amputation: Rinse amputated part of penis with saline, wrap in saline-soaked gauze, and place in plastic bag over ice. Avoid direct contact with ice as hypothermic injury can occur. Reanastomosis of urethra, corporeal bodies using microscurgical techniques to reconnect nerves and dorsal penile vessels yields best results. If microsurgery equipments are not available, macroscopic reanastomosis of urethra and corporal bodies should be performed instead.
   • Testicular injury: Early surgical exploration should be pursued for any penetrating injury or significant blunt trauma. Goal involves testicular salvage, debridement of necrotic tissue, and control of bleeding. After debridement, small absorbable sutures should be used to close the tunica albuginea.  If the testicle cannot be reconstructed, orchiectomy is recommended.
   • Genital skin loss: blast injury can often cause significant burn and skin loss in penis and scrotum. Suprapubic cystostomy should be considered early to simplify wound care and prevent urethral complications related to prolonged catheterization. The principles of treating genital burns are otherwise similar to other burns. Early debridement of eschar and split thickness skin graft should be pursued.  In most cases of scrotal injury, primary closure of scrotum is possible. However, when there is extensive loss of scrotum, local skin flaps are recommended over thigh pouch for reconstruction.  

¹ Advance one grade if multiple injuries were found in the same organ
² Based on most accurate assessment at autopsy, laparotomy, or radiologic study

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