- Kidney is the most commonly injured GU organ in trauma; kidneys are fixed only by the renal pelvis and vascular pedicle, making them prone to deceleration injury.
- Pediatric kidney is more susceptible to trauma due to immature pliable thoracic cage, weaker abdominal musculature, less perirenal fat, and lower abdominal position.
- Degree of hematuria does NOT consistently correlate with severity of renal injury — presence/absence of hematuria should not be the sole determinant.
- 2020 AUA imaging indications for renal trauma (5): gross hematuria, microscopic hematuria with SBP <90 mmHg, mechanism concerning for renal injury, PE findings concerning for renal injury, penetrating injury of abdomen/flank/lower chest.
- Imaging of choice in suspected renal trauma: CT abdomen/pelvis with IV contrast, immediate and delayed images. Major CT limitation: cannot reliably define a renal venous injury — medial hematoma strongly suggests venous injury.
- CT findings suspicious for significant renal injury (6): medial laceration, medial hematoma (vascular pedicle), medial urinary extravasation (pelvis/UPJ), hematoma >3.5 cm, lack of parenchymal contrast enhancement (main renal artery injury), active intravascular contrast extravasation.
- Fluid collection differentiation: hematoma >30 HU, urinoma 0–20 HU, abscess with rim enhancement.
- AAST kidney scale: Grade I subcapsular hematoma/contusion → Grade V main renal artery/vein laceration or shattered kidney; advance one grade for bilateral injury up to grade III.
- Hemodynamically stable: non-invasive management (monitoring, bed rest, ICU, transfusion, imaging). Hemodynamically unstable: immediate intervention (surgery or selective angioembolization).
- Follow-up CT in renal trauma indicated for: clinical signs of complications (fever, worsening pain, ongoing blood loss, abdominal distention), or AAST Grade IV–V injuries — done after 48 hours.
- Risk factors for bleeding/intervention in grade 3–4 injuries: medial hematoma, hematoma >3.5–4 cm, contrast extravasation on imaging. Delayed renal bleeding can occur up to several weeks but usually within 21 days.
- Urinary extravasation alone from grade IV laceration or forniceal rupture resolves spontaneously in >90% with non-operative management.
- Hypertension after renal trauma mechanisms: renal vascular injury (Goldblatt kidney), Page kidney (compression by extravasated blood/urine), post-trauma AV fistula, ureteral/UPJ obstruction.
- Ureteral trauma accounts for only 1% of urologic injuries; iatrogenic causes most common — hysterectomy 54%, colorectal surgery 14%.
- Methylene blue contraindications: pregnancy (teratogenic), SSRI/SNRI use (serotonin toxicity from MAOI effect), G6PD deficiency (methemoglobinemia/hemolysis), Heinz body anemia.
- Prophylactic ureteral stenting does NOT reduce ureteral injury risk in gynecologic surgery (RCT data) but may increase intraoperative recognition.
- Missed ureteral injury signs/symptoms: flank pain, fever, leukocytosis, ileus, abdominal distention, urinary fistula. Significant ureteral injury can occur in the absence of hematuria.
- AAST ureter scale: I contusion/hematoma without devascularization → V laceration with avulsion and >2 cm devascularization.
- Ureteral injury management: stable → immediate repair (Heineke-Mikulicz converts longitudinal to transverse to avoid narrowing); unstable → temporary urinary drainage with delayed repair (stent only, observation, exteriorize ureter, tie off ureter with PCN).
- Gunshot ureteral contusion: excise devitalized tissue + adjacent segment of normal ureter (to eliminate late ischemia/stricture from blast effect); spatulate ends 5–6 mm at 180° apart.
- Postoperatively discovered ureteral injuries should be immediately repaired when detected within 72 hours (Campbell's).
- Reconstruction by location: upper (above iliac vessels) — ureterocalycostomy, ureteroureterostomy, transureteroureterostomy, ileal interposition, autotransplant; lower (below iliac vessels) — ureteroneocystostomy, psoas hitch, Boari flap.
- Bladder injuries: ≈60% extraperitoneal, ≈30% intraperitoneal, ≈10% both. 83–95% of bladder injuries associated with pelvic fracture; only 5–10% of pelvic fractures have bladder injury.
- Gross hematuria is the most common indicator of bladder injury. Increased Cr/BUN due to peritoneal absorption of urine is a feature of intraperitoneal rupture.
- 2020 AUA cystography indication: absolute — gross hematuria + pelvic fracture; relative — gross hematuria with mechanism, or pelvic ring fracture + clinical indicators.
- Cystography technique: fill bladder to discomfort or 300–350 mL minimum (false negatives reported with only 250 mL); CT cystography requires 1:6 contrast dilution.
- Extraperitoneal bladder rupture: 22-Fr Foley × 2–3 weeks; intraperitoneal bladder rupture: prompt surgical repair (failure → peritonitis, sepsis).
- AUA immediate bladder repair indications: NOVA mnemonic + intraperitoneal rupture, bone spicules, rectal injury, bladder Neck injury, ORIF, Vaginal injury, Abdominal injury repair.
- After bladder repair, urethral catheter drainage alone is recommended (no SP cystostomy benefit) — exceptions: long-term catheterization need, complex repairs, significant hematuria.
- 10–30% of bladder rupture patients have concomitant urethral injury — if blood at meatus or catheter does not pass, do RUG first.
- Posterior urethral injuries almost exclusively associated with pelvic fractures — 10% of males, up to 6% of females. Bulbomembranous junction more vulnerable than prostatomembranous due to UG diaphragm/puboprostatic ligament anchoring.
- Anterior urethral injuries: most commonly involve bulbar urethra (straddle), as it is fixed beneath the pubis.
- Urethral injury indicators: blood at meatus (most common), inability to urinate, perineal/genital ecchymosis, high-riding prostate (males), labial edema/vaginal blood (females).
- Buck's fascia disruption → blood/urine extends to scrotum (below Dartos), abdominal wall (below Scarpa's), with posterior limit at Colles' fascia ("butterfly hematoma").
- RUG is modality of choice for suspected urethral injury — oblique position, 12-Fr catheter or catheter-tip syringe in fossa navicularis, 20–25 mL undiluted water-soluble contrast.
- Blind catheter passage prior to RUG should be avoided. In partial urethral disruption, a single attempt by experienced team member may be made.
- PFUI management: immediate suprapubic tube (gold standard) with delayed repair at 3 months (open perineal anastomotic urethroplasty). Immediate sutured repair is associated with unacceptably high ED and incontinence rates.
- Lithotomy time should be limited to ≤5 hours during complex urethral reconstruction to prevent lower extremity complications.
- After posterior urethroplasty: 5–15% recurrent anastomotic stenosis; impotence/incontinence usually from the pelvic fracture itself, not the repair.
- Straddle injury anterior urethra: SPT (or primary realignment in less severe) with delayed repair. Immediate operative debridement contraindicated due to indistinct injury borders.
- Penetrating anterior urethral trauma: prompt surgical repair with spatulated primary anastomosis — superior to delayed reconstruction (opposite of PFUI/straddle).
- Female urethral disruption from pelvic fracture: immediate primary repair or at least realignment over catheter — delayed reconstruction problematic due to short (~4 cm) urethra.
- Penile fracture: disruption of tunica albuginea with rupture of corpus cavernosum; usually transverse, unilateral, proximal shaft, ventral or lateral. Tunica thinnest at 5–7 o'clock positions (Peyronie's is dorsal).
- Bilateral corporeal injuries in 10% of penile fractures and more commonly associated with urethral injury (urethral injury in 10–22% of fractures overall).
- "Eggplant deformity" — Buck's intact, hematoma between skin and tunica. "Butterfly hematoma" — Buck's disrupted.
- Suspected penile fracture should be promptly explored and surgically repaired; delay up to 7 days does not adversely affect outcomes.
- Ultrasound is preferred imaging for penile fracture (rapid, available, accurate); MRI most accurate; penile Doppler and cavernosography have very high false-negative rates.
- Dog bites: copious irrigation, debridement, immediate primary closure with drain + broad-spectrum antibiotics (amox/clav, cefoxitin, cefotan, or clinda + cipro), tetanus/rabies as appropriate. Human bites: contaminated — often should NOT be closed primarily.
- Penile amputation reimplantation possible if <16 hours cold ischemia OR <6 hours warm ischemia; microvascular anastomosis preserves skin (dorsal artery/vein) and sensation (dorsal nerve).
- Testicular rupture must be considered in all blunt scrotal trauma. Approximately 5% of spermatic cord torsions are precipitated by trauma — consider torsion in significant pain without major trauma signs.
- US findings suggestive of testicular fracture: heterogeneous parenchyma, disruption of testicular contour/tunica albuginea. Normal/equivocal US should NOT delay exploration when PE suggests damage.
- Scrotal exploration indications: imaging findings of rupture, equivocal imaging with suspicion, large hematoma (even without rupture), clear PE findings, penetrating injury, significant hematocele (up to 80% have rupture).
- Early exploration <72 hours: salvage rate >90%; orchiectomy rates 3–8× higher with conservative/delayed management. Penile fracture has 7-day window; ischemic priapism shunt at 72 hours.
- ~30% of scrotal gunshot wounds injure both testes — consider contralateral exploration depending on PE and projectile path.
- Most common cause of extensive genital skin loss: Fournier gangrene (necrotizing polymicrobial infection). If urethral catheter used in genitalia burn, remove after 72 hours to prevent urethral slough/fistula.
- Penile reconstruction: thick (0.012–0.015 inch) non-meshed split-thickness skin grafts preferred; skin grafts on shaft never regain normal sensation but sexual function often preserved via intact glans sensation.
- Scrotal reconstruction: defects up to 50% closable directly; meshed split-thickness skin grafts preferred. Thigh pouches NOT recommended initially in infection until stabilized.