80% of kidney injuries have associated trauma.
No direct relationship between presence or absence of microscopic hematuria and degree of trauma. 95% of all patients with renal trauma have at least some hematuria > 5 RBCs/HPF. Children with microscopic >50 RBCs/HPF have low likelihood of significant renal injury. If only microscopic urine, can ignore if SBP<90, no severe decel injury, no gross blood (Am J Surg 1992, J Urol 1985)
CT with IV contrast most sensitive/specific. Urinary extravasation can’t be determined until contrast-enhanced urine is excreted into collecting system. Usually 10 minute delay. Focused ultrasound only identifies free intraperitoneal fluid. It does not specifically look for renal injury. Does not identify renal vascular injury as well.
Renal Grading system used for degree of injury. Nephrectomy in 82% of grade V injuries. Majority of renal injuries can be managed conservatively. If going non-operative route, make sure there’s no ureteral injury.
Renal exploration/intervention with expanding, pulsatile, non contained retroperitoneal hematoma and renal avulsion (grade V) injury.
Urinary extravasation alone is not indication for exploration as it usually spontaneously resolves (though this seems to be only retroperitoneal bladder injuries). Extravasation from renal pelvis or ureteral injury does need treatment.
Complications: AV fistula can occur and lead to delayed bleeding. Treat usually with embolization. Urinomas can occur a few weeks to years later and present with abdominal pain, mass, and fever. Perinephric abscess can present similarly.
Protected in retroperitoneal. 90% occur with penetrating trauma. Only 70% have gross or microhematuria.
Partial tears can be scented. Most require operation, likely including percutaneous nephrectomy. Diagnosis with CT with IV contrast with 10 minute delay best for assessment.
80% associated with pelvic fractures. Gross hematuria seem on 95%. Gross hematuria with pelvic fracture requires cystogram. Retrograde cystogram is gold stand. Bladder filled in retrograde fashion by gravity feed with enough contrast (350mL) to distend bladder (distended to attempt to dislodge thrombi on wall to accurately assess).
Extraperitoneal ruptures are most common. Intraperitoneal ruptures always require surgical exploration and repair – usually due to distended bladder with rupture at weakest point – dome of bladder. Extraperitoneal can be treated with foley and will likely heal in over 10 days. Need prophylactic antibiotics.
Posterior urethral injury: high-riding prostate, usually due to major blunt trauma or pelvic fracture.
Anterior urethral injury: blunt trauma to peritoneum, blow to bulbar segment, saddle injury. Sometimes see ‘butterfly’ perineal hematoma from Buck’s fascia violation.
Look for blood at penile meatus. Don’t place foley due to possibly turning incomplete into complete tear. Will need retrograde urethrogram before cauterization. Gentle injection of 20-30mL of contrast into urethra with X-ray. Likely treatment emergently with suprapubic catheter.
Contrast/Jelly technique: 25cc of contrast and 25cc of KY jelly; mix in urine cup. Draw jelly into 60mL syringe. Under fluoro with oblique view, inset tip into penis and pull it toward yourself, pinching the meatus. Slowly inject contrast, watching to contrast column on fluoro screen. Once easy flow into bladder, can stop the study. If noted extravasation, stop study and call urology. One small study found one blind attempt didn’t have any major consequences (J Trauma, 2007)
External Genitalia Injury
Penile fracture: rupture of corpus cavernosum (pair of ‘muscles’ in dorsal aspect of penile shaft). Usually cracking sound, immediate detumescence, rapid swelling, discoloration and visible deformity. Penis will deviate away from side of injury – ‘eggplant deformity.’ Diagnosis made clinically. Need retrograde urethrogram. Can also use ultrasound for assessment. Treat with surgical exploration by urology. Dorsal artery/vein rupture can look similar and is called ‘false penile fracture.’ Still requires surgical exploration most times. Taghaandan – erect penis is forcibly pulled down to achieve detumescence – kurtish word for ‘to click.’ Can cause penile fractures.
Testicular contusions/rupture – tunica vaginitis fills with blood, forming hematocele. Color doppler is usually used for diagnosis. Treatment for testicular injury is conservative though still need urology consult for possible exploration.
All penetrating trauma to penis and testicles need surgery.
Tintinalli, Seventh Edition, Chapter 262: Genitourinary Trauma
Rosens, Chapter 40: Genitourinary System