Overview
Anatomic divisions
Upper genitourinary (GU) tract:
- Kidneys
- Ureters
Lower GU tract:
- Bladder
- Urethra
- External genitalia
Epidemiology
- Approximately 3%–10% of hospitalized trauma patients have an injury to the GU system.
- Penetrating injuries (i.e. gunshot and stab wounds) account for 15% of all GU injuries.
- Uncommon and rarely life threatening, unless kidney vascular structures are involved
- The kidneys are the most injured GU organs, usually by blunt trauma.
- Ureteral trauma is very rare, most commonly due to penetrating injury (most cases are iatrogenic).
- Bladder injuries usually are associated with pelvic fractures.
- Urethral injuries are rare and occur almost exclusively in men.
Etiology
Blunt injuries:
- Direct blow to the flanks or the back
- Falling down from a height
- Car accident (rapid deceleration injury)
Penetrating injuries:
- Bullet
- Stabbing
- Surgical trauma (iatrogenic injury)
Injuries to the Upper GU Tract
Renal injuries
Pathophysiology:
- Kidneys are protected by lower ribs, back musculature, and perinephric fat.
- Significant force is required to injure kidneys.
- Common mechanisms:
- Motor vehicle collision (MVC)
- Falls
- Direct blows
- Lower rib fractures
Clinical presentation:
- Flank pain/tenderness
- Hematuria (gross or microscopic)
- Flank ecchymosis
- Often in association with posterior rib or spine fractures
- May be associated with other intra-abdominal injuries
Diagnosis:
- Urinalysis:
- Detects hematuria
- Less sensitive for penetrating trauma
- Degree of hematuria does not always correlate with severity.
- Imaging:
- Plain X-ray:
- For associated injuries (e.g., rib fractures)
- Retained bullets/foreign bodies in penetrating trauma
- Ultrasound: for detection of intraperitoneal fluid (blood)
- Computed tomography (CT) scan:
- Test of choice in a hemodynamically stable patient
- Delayed images needed to detect contrast extravasation (bleeding)
- Also detects other associated injuries
- Plain X-ray:
Grade IV left renal injury from a motor vehicle accident
Contrast-enhanced CT in arterial phase in axial section showed contrast medium extravasation (black arrow), perirenal hematoma (open arrow), and pararenal hematoma (white arrow).
Management:
- First step: stabilization, resuscitation and identification of other life-threatening injuries
- Renal injuries themselves are rarely life-threatening except for major avulsions of renal vessels.
- Management depends on severity:
- Graded based on American Association for the Surgery of Trauma (AAST) classification (grades Ⅰ through Ⅴ):
- Grade Ⅰ-Ⅲ injuries do not involve injury to urinary collecting system or vasculature.
- Grades Ⅳ-Ⅴ injuries are most severe and involve injury to major vessels and/or urinary collecting system.
- Graded based on American Association for the Surgery of Trauma (AAST) classification (grades Ⅰ through Ⅴ):
- AAST grade Ⅰ and Ⅱ injuries are usually managed nonoperatively.
- Grade Ⅲ-Ⅳ: may require nephrectomy, angiographic embolization or stenting for vascular injuries
Ureteral injuries
Mechanisms:
- Ureteral injury is rare.
- 75% are iatrogenic (during gynecologic, urologic, or general surgical procedures).
- Most common blunt trauma is avulsion of uretero-pelvic junction (deceleration injury).
Symptoms:
- May have minimal initial symptoms and often missed
- Delayed symptoms: fever, flank pain, and palpable mass (urinoma)
Diagnosis:
- Urinalysis may or may not show hematuria.
- Can be picked up on abdominal CT scan
- Intravenous pyelography (IVP) if CT is non-diagnostic
Management:
- Definitive management should be undertaken after other immediately life-threatening injuries have been addressed.
- Ureteral injuries usually require some reconstruction:
- Cystoscopic stent placement
- Operative repair over stent
- Urinary diversion
Iatrogenic ureteral trauma sustained during ureter instrumentation
Intra-operative pyelogram shows contrast extravasation (arrow) from left ureter.
Complications
- Urine extravasation can cause urinomas, abscesses.
- Hydronephrosis
- Calculus formation
- Renal hypertension
- Loss of renal function
Injuries to the Lower GU Tract
Anatomy
- Injuries to the lower GU tract include:
- Bladder
- Urethra
- Perineum
- Genitalia
- Highly associated with pelvic fractures
Bladder injuries
Extraperitoneal:
- Confined to extraperitoneal space (the anterior bladder wall or the bladder neck)
- Symptoms:
- Scrotal swelling
- Localized lower abdominal pain
- Inability to urinate
- Gross hematuria
- Diagnosis:
- Retrograde cystogram
- Retrograde CT cystography
- CT abdomen and pelvis: shows contrast extravasation from the bladder
- Management:
- Non-operative
- Continuous prolonged bladder drainage with a Foley catheter
Intraperitoneal:
- Communicating with the peritoneum (the dome of the bladder)
- Symptoms:
- No desire to urinate
- Peritonitis and rebound tenderness
- Referred pain to the shoulder due to diaphragmatic irritation
- Diagnosis:
- Ultrasound, usually part of focused assessment with sonography in trauma (FAST exam)
- Abdominal CT scan
- Management: surgical repair
Intraperitoneal bladder rupture: cystogram showing leakage of the contrast into the peritoneal cavity
Image: “Intraperitoneal bladder rupture mimicking acute renal failure” by Arun KG. License: CC BY 2.0Urethral injuries
Symptoms:
- Blood at the urethral meatus
- Hematuria
Anterior urethral injuries:
- Injury to bulbar (spongy) urethra
- Associated with perineal saddle injury
- Blood accumulates in scrotum → scrotal hematoma, ecchymosis
Posterior urethral injuries:
- Injury to membranous urethra
- Associated with pelvic fracture
- Urine leaks into retropubic space.
- High-riding prostate on digital rectal exam (DRE)
Diagnosis: retrograde urethrogram (RUG)
Management:
- Bladder drainage (suprapubic catheter) with or without delayed repair
- Urethral catheterization is contraindicated if blood is seen at the urethral meatus.
Patient with a history of pelvic trauma:
(a) A retrograde urethrogram (RUG) is performed as contrast is simultaneously injected into the posterior urethra through the flexible cystoscope, with the tip in the distal prostatic urethra.
(b) Imaging accurately demonstrating the length and location of the defect
Perineal injury
- Ecchymosis with no laceration is managed with perineal pressure (scrotal support with gauze packing).
- Perineal lacerations with urethral or bladder injury need urology consult to exclude the presence of urethrocutaneous or vesicocutaneous fistula.
- Suspected testicular rupture/torsion: surgical management to evaluate the salvageability of the tissue
Penile and scrotal injury
- Ultrasound is the preferred imaging.
- Management:
- Non-operative: if tunica albuginea and dartos fascia are intact
- Penetration requires surgical exploration/repair.
Penile fracture: clinical photograph showing a swollen penis with ‘egg plant’ deformity and deviation to the right side
Image: “Synergism of clinical evaluation and penile sonographic imaging in diagnosis of penile fracture: a case report” by Bello JO. License: CC BY 2.0
Sonourethrogram of penile fracture
Image: “Synergism of clinical evaluation and penile sonographic imaging in diagnosis of penile fracture: a case report” by Bello JO. License: CC BY 2.0
A: Sonourethrogram at the distal aspect of the penile shaft, showing a normal right (RT CC) and left corpus cavernosa (LT CC) and normal urethra (U)
B: Sonourethrogram at the proximal 1/3 of the penile shaft showing a normal right corpus cavernosum, and a ruptured left corpus cavernosum with associated hematoma (H)
Complications
- Urinary incontinence
- Sexual dysfunction
- Urethral stricture
References
- Runyon, M. (2020). Blunt genitourinary trauma: Initial evaluation and management. Retrieved December 19, 2020 from https://www.uptodate.com/contents/blunt-genitourinary-trauma-initial-evaluation-and-management
- Voelzke, B. (2020). Overview of traumatic lower genitourinary tract injuries in adults. Retrieved December 19, 2020 from https://www.uptodate.com/contents/overview-of-traumatic-lower-genitourinary-tract-injury
- Voelzke, B. (2020). Overview of traumatic upper genitourinary tract injuries in adults. Retrieved December 19, 2020 from https://www.uptodate.com/contents/overview-of-traumatic-upper-genitourinary-tract-injuries-in-adults
- Runyon, M. (2020). Penetrating trauma of the upper and lower genitourinary tract: Initial evaluation and management. Retrieved December 19, 2020 from https://www.uptodate.com/contents/penetrating-trauma-of-the-upper-and-lower-genitourinary-tract-initial-evaluation-and-management
- Diercks, D., & Clarke, S. (2020). Initial evaluation and management of blunt abdominal trauma in adults. Retrieved December 20, 2020 from https://www.uptodate.com/contents/initial-evaluation-and-management-of-blunt-abdominal-trauma-in-adults
- Pereira, B.M.T., de Campos, C.C.C., Calderan, T.R.A. et al. (2013). Bladder injuries after external trauma: 20 years experience report in a population-based cross-sectional view. World J Urol 31: 913-917
- Bayne, D., Zaid, U., Alwaal, A., Harris, C., McAninch, J., & Breyer, B. (2016). Lower genitourinary tract trauma. Trauma 18(1):12-20.
- Koraitim, M.M., Marzouk, M.E., & Atta, M.A. (1996). Risk factors and mechanism of urethral injury in pelvic fractures. Br J Urol. 77(6):876–80.
- Chapple, C., Barbagli, G., & Jordan, G. (2004). Consensus statement on urethral trauma. BJU Int. 93(9):1195–202.
