Genitourinary trauma

Introduction

• Myriad retroperitoneal, intravascular and intra-peritoneal injuries can occur, many of which require operative intervention
• Emergency physician assessment is crucial in deciding on ongoing care requirements

Penetrating flank trauma

• Flank bounded by anterior and posterior axillary lines, 6^th rib superiorly and inferiorly by iliac crest
• Solitary retroperitoneal injury will not yield peritonism and reliance on physical exam is fraught with danger
• Any organ can be damaged by this
• Clinical features
  • For gunshot wounds, consider nature of gun, distance between shooter and patient and attempt to identify an exit wound and reconstruct the bullet path
  • Bullets may ricochet off bone creating unique paths
  • PR exam with blood on glove indicates bowel injury
  • Blood in urine or at urethral meatus suggests bladder/kidney or urethral injury

Penetrating flank trauma

• Diagnosis
  • If unstable or peritonitic – require urgent laparotomy
  • Triple (PO/IV/PR)-contrast CT (diagnostic modality of choice)
    • Can detect trajectory and evaluate the retroperitoneum
    • Less sensitive for injuries to diaphragm or colon
    • Add PR contrast if suspicion of rectal or sigmoid trauma
    • Wound track anywhere near diaphragm or bowel necessitates close scrutiny for injury to either
  • US
    • Limited sensitivity for hollow organ or retroperitoneal injury
  • Local wound exploration
    • High false-positive rate of 14-45%
  • Diagnostic laparoscopy
    • Very sensitive for detection of peritoneal violation and can help prevent morbidity and mortality from unnecessary laparotomy

Penetrating flank trauma

• Treatment and disposition
  • Broad-spectrum antibiotics in case of peritonitis from bowel flora
  • Exploratory laparotomy indicated
    • Haemodynamically unstable
    • Peritonism after gunshot wound to flank
  • Conservative approach to flank gunshot wounds may be indicated if no peritonism and penetrating wounds appear to be tangential
  • Conservative approach to flank stab wounds appropriate if stable, lack peritonism and local wound exploration or triple-contrast CT has been performed
  • Admit all patients for observation and serial examination

Penetrating buttock trauma

• Borders: Iliac crest to gluteal fold and greater trochanters
• Upper zone and lower zone divided by level of trochanters
  • Upper zone (higher risk of major injury):
    • Major pelvic vascular structures
    • Sciatic nerve
    • Ilium/sacrum
    • Lower colon
    • Upper rectum
    • Bladder
    • Female reproductive organs
  • Lower zone:
    • Male bladder, prostate, urethra, external genitalia and lower part of rectum

Penetrating buttock trauma

• Most commonly injured organs in stab wound:
  • Rectum, superior gluteal artery and iliac artery
• Most commonly injured organs in gunshot wound:
  • Small bowel, colon, rectum, bony pelvis and bladder
• Position of patient during trauma helps calculate trajectory and organs at risk
• Diagnosis
  • PR and stool guaiac testing (negative guaiac does not rule out rectal/bowel trauma)
  • Evalute for haematuria
  • Assess peripheral pulses and neurological examination
    • Sciatic and femoral nerve fx specifically

Penetrating buttock trauma

• Exploratory laparotomy indicated in:
  • Haemodynamic instability or peritonism
• Broad-spectrum antibiotics indicated if peritonitic

Penetrating buttock trauma

• Non-operative management
  • If stable and no peritonism
  • Requires serial examination +- FAST, CT, sigmoidoscopy, cystourethrogram and angiography
    • Upper zone stab wounds can undergo local wound exploration to identify muscle violation
      • If no muscle violation, can observe
      • If muscle violation, requires CT and rigid sigmoidoscopy + cystourethrogram for haematuria
    • Triple-phase CT should be obtained in all stable patients
    • Obtain cystourethrogram if blood on urinalysis or wound is close to the GU tract
      • Can obtain cystogram with CT using rectal and IV contrast with clamping of catheter or a separate study
    • Rigid sigmoidoscopy is advised if any concern of rectal injury or suspected trajectory of bullet
    • If pelvic haematoma evident, angiography or venography (usually CT angiography) is indicated

Penetrating flank trauma

• Labs
  • FBC, Group and save
  • CXR
  • Urine pregnancy test
  • Urinalysis

Genitourinary trauma

• Introduction
  • Blunt trauma most commonly falls, assaults, MVA and sports injuries
  • Penetrating trauma mostly gunshot and stab wounds
  • Most ureteral injuries are due to penetrating trauma
  • Most bladder injuries due to pelvic trauma
  • Urethral injuries seen in 5-10% of pelvic fractures
  • Children are more susceptible to genitourinary trauma than adults
    • Kidneys large relative to body size and lack adipose tissue
  • Complications can include renal impairment, urinary incontinence and sexual dysfunction

Genitourinary trauma

• History
  • Sudden deceleration risks major vascular disruption and parenchymal damage to kidneys and bladder, even in the absence of symptoms/signs
  • Inability to urinate
    • Empty bladder
    • Too painful
    • Consider bladder perforation, urethral injury and spinal cord injury

Genitourinary trauma

• Examination
  • Inspect perineum and underwear for bruising/blood
  • Inspect buttock folds for ecchymoses/skin breaks as may indicate open pelvic fracture
  • Probing may disrupt clot
  • Rectal examination confirms sphincter tone, position of prostate and blood
    • If prostate boggy or high-riding, assume membraneous urethral trauma until retrograde urethrogram performed
    • Examine scrotum in males
    • Palpate and inspect the penis looking for deformity, ecchymosis and blood at meatus
    • In females examine the introitus for lacerations and haematomas (may accompany pelvic fractures)
      • Perform speculum examination if present
      • If missed, complications include infection, fistula formation and haemorrhage

Genitourinary trauma – Kidney injuries

• Renal injury seen in 10% of abdominal trauma
• Most will have other abdominal injuries
• Includes lacerations, avulsions and haematomas of kidney and renal pelvis
• Renal vascular injuries are uncommon but must be considered
• Urinalysis
  • No direct relationship between presence, absence or degree of microscopic haematuria and severity of injury
  • Renal pedicle injuries and segmental arterial thrombosis may be present without haematuria
  • Gross haematuria has some predictive value for more severe renal injury
  • SBP< 90 and microscopic haematuria have a higher likelihood of severe injury
  • Children with <50 RCC/HPF have a low likelihood of significant renal injury
  • Do not need to image isolated microscopic haematuria unless associated transient hypotension or rapid deceleration mechanism

Genitourinary trauma – Kidney injuries

• Imaging
  • IV contrast-enhanced CT is gold-standard for stable patient
    • Detects contusions, lacerations, haematomas and perfusion abnormalities
    • Early contrast extravasation is consistent with ongoing haemorrhage
    • Urinary extravasation cannot be detected until 10 minutes after IV delivery
      • Therefore, delayed KUB is recommended to exclude urinary extravasation from any source
      • If kidney is normal and there is no abnormal fluid collection in perinephric, retroperitoneal or peripelvic areas, delayed scan can be omitted
  • USS may be helpful for identifying and following post-operative fluid collections or conservatively managed patients
  • Renal angiography can identify vascular injuries +- embolisation

Genitourinary trauma – Kidney injuries

• Grading of renal injury
  • Correlates with renal dysfunction, need for operative repair and nephrectomy

Genitourinary trauma – Kidney injuries

• Treatment of kidney injuries
  • Renal exploration indicated if (whether blunt or penetrating injury):
    • Life-threatening haemorrhage
    • Expanding, pulsatile or non-contained retroperitoneal haematoma (thought to be from renal avulsion injury)
    • Renal avulsion injury (Grade V)
  • Predictive factors for nephrectomy
    • High injury grade
    • High ISS
    • Large blood requirements
    • Haemodynamic instability
  • Urinary extravasation alone is not an indication as resolves spontaneously in most cases
    • Extravasation from renal pelvis or ureteral injury does necessitate surgical repair

Genitourinary trauma – Kidney injuries

• If suspected renal tract trauma and stable arrange CT
  • If CT shows no renal pelvis, vacular or ureteral injury and pt remains stable, observe until gross haematuria clears
  • If CT scan shows renal pelvic, vascular or ureteral injury, obtain surgical consult
• Renal vascular injury
  • Identified on CT and requires urgent surgical consult to minimise time of ischaemia
  • Should reperfuse within 4-20 hours (depending on local protocols)

Genitourinary trauma – Kidney injuries

• Complications
  • Delayed bleeding, urinary extravasation, urinoma, perinephric abscess, hypertension and renal failure
    • Delayed bleeding can occur up to 1 month later and is usually due to AV fistula seen in 25% of Grade III/IV injuries treated conservatively
      • Angiographic embolisation +- nephrectomy
    • Urinomas may present days to years later and are usually percutaneously drained +- stent
    • Perinephric abscesses require percutaneous drainage
    • Hypertension (see next slide)

Genitourinary trauma – Kidney injury

• Hypertension can occur days to years later and may be due to:
  • Renal artery injury
  • Devascularised tissue
  • Renal parenchymal compression by clot
  • AV malformation
  • Requires medical +- nephrectomy treatment
• Disposition and follow-up
  • In isolated Class I injury
    • If renal contusion (microscopic haematuria with normal imaging) – D/C home after Urology consult
    • Subcapsular haematoma admit for repeat exam + Hct
  • Gross haematuria warrants admission and bed rest until clears
  • Grade II or higher need admission under trauma/gen surgeon/urologist

Genitourinary trauma – Ureteral injury

• Isolated injury is rare in trauma as well protected in retroperitoneum
• 80% occur iatrogenically in operations
• 90% of those that do occur secondary to external trauma are due to penetrating trauma (81% gunshot, 9% stab wounds)
• Easily missed as no specific examination findings
• 70% of patients have gross or microscopy haematuria (but 30% do NOT)

Genitourinary trauma – Ureteral injury

• Delayed phase CT KUB with contrast if suspicion exists
  • Extravasation of contrast along ureter is diagnostic
• IV or retrograde pyelography is indicated if suspicion still remains after normal CT
• Treatment and disposition
  • Operative treatment for all
    • Partial tears – stented and primarily repaired over top if lacerated
    • Complete tears – Reconstruction required
  • Complications – Urinary leakage, urinoma, periureteral abscess, peritonitis, ureteral stricture and urinary fistula

Genitourinary trauma – Bladder injuries

• 2% of blunt abdominal trauma cases with 70-97% associated with pelvic fractures
• Direct blow to distended bladder can cause rupture
  • Suspect if intoxicated (bladder distended) in MVA
• Presentation
  • Gross haematuria with lower abdominal pain raises suspicion
  • Abdominal swelling from urinary ascites, perineal or scrotal oedema for urinary extravasation and inability to void are common findings
  • Penetrating trauma to pelvis, rectum and buttock can cause bladder injury
  • Gross haematuria in the setting of pelvic fractures requires retrograde cystourethrogram
  • Microscopic haematuria associated with pelvic ring fracture may suggest bladder injury but it’s not clear how strong this association is and if cystourethrogram is indicated in all cases

Genitourinary trauma – Bladder injuries

• Retrograde cystogram is gold standard
  • Contrast extravasation into peritoneal cavity or retroperitoneum is diagnostic
  • Need at least 350mL to distend bladder for accurate imaging
• A contrast-enhanced CT with passive bladder filling, even with a clamped catheter is not sensitive enough to rule out bladder rupture
• Sonographic diagnosis is not accurate

Genitourinary trauma – Bladder injury

• Treatment and Disposition
  • Extraperitoneal (retroperitoneal) are most common (55%), then intraperitoneal (38%) and rest combined
  • Admit all for observation (high likelihood of associated injuries)
  • Intraperitoneal all require operative repair
    • Missed intraperitoneal rupture can lead to urinary ascites, abscess, peritonitis and sepsis
  • Extraperitoneal rupture can be managed with bladder drainage alone (85-90% will heal within 10 days and rest within 3 weeks)
    • Operative repair may be indicated if:
      • Urinary catheter does not allow adequate drainage
      • Associated rectal or vaginal injury
      • Associated bladder neck injury
      • Open fixation of pelvic fracture (to avoid contamination of hardware)

Genitourinary trauma – Urethral injuries

• Far less common in women (4cm vs. 20cm)
• Posterior urethral injuries
  • Prostatic and membraneous urethra
  • Injuries here indicate major blunt force trauma from deceleration or fall from height
  • Shearing at prostatic-membraneous junction
  • Seen in 10% of pelvic fractures
• Anterior urethral injuries
  • Fixed bulbar segment (most commonly injured) and pendulous (penile) segment
  • Usually direct perineal trauma, either blunt or penetrating
  • Often missed and may present years later with stricture
  • Straddle injury is the classic mechanism or instrumentation
• Evaluate for female urethral injuries in extensive pelvic fractures

Genitourinary trauma – Urethral

• Presentation
  • Mechanism, pelvic fracture, traumatic/difficult catheterisation, blood at meatus, haematuria, dysuria, inability to void, perineal haematoma, high-riding prostate
  • Classic triad of posterior urethral injury = High-riding prostate, haematuria and urinary retention
  • Most female injuries will have PV bleeding requiring careful inspection +- speculum

Genitourinary trauma – Urethral

• Diagnosis
  • Retrograde urethrogram prior to catheterisation
    • 20-30mL injected gently into urethral meatus and obtain plain film
    • Extravasation is diagnostic
      • Partial anterior injury – Extravasation at site of injury and outlining urethra proximal to injury
      • Complete anterior injury – Extravasation at site without contrast proximal to site of injury
    • If performed before CT, can obscure CT images, preventing diagnosis of life-threatening injuries or embolisation (discuss with radiologist first)
    • If catheter already in place and urethral injury suspected, inject contrast around the catheter in standard fashion
  • In males, for every 1mm of symphysis pubis diastasis or inferomedial pubic bone fracture displacement, risk of urethral injury increases 10%

Genitourinary trauma – Urethral

• Males with posterior urethral injury
  • Classically: Immediate SPC with delayed surgical repair
    • Early endoscopic repair may lead to good potency and continence while reducing rates of urethral stricture
• Penetrating injuries to anterior urethra
  • Surgical exploration and repair
• Female urethral injuries
  • Diagnosis is often clinical so more difficult
  • Urethrography is far more difficult
  • Concomitant bladder injury needs to be excluded with CT cystography
  • Consider antegrade cystogram through suprapubic tube +- cystoscopy if diagnosis uncertain
• Admit all as high rates of associated injuries

Genitourinary trauma – External genitalia

• Introduction
  • 25% of patients require transfusion for this injury alone
  • >50% of testicular trauma is a result of sporting activity
  • In contusion and rupture of testicles, blood fills the tunica vaginalis forming a haematocoele (tender firm mass that fails to transilluminate)
  • If tunica albuginea is disrupted, a rupture has occurred
  • Traumatic dislocation of the testicle is rare and mostly occurs in straddle injuries from motorcycle accidents
    • Empty hemiscrotum suggests this
  • Open wound to scrotum suggests possible testicular involvement
  • Low threshold for diagnostic imaging as external signs of trauma may not correlate well with degree of testicular injury

Genitourinary trauma – External genitalia

• Diagnosis
  • Doppler USS is gold standard
  • Contrast-enhanced USS +- MRI may be useful if suspicion remains despite normal US study
  • CT important to rule out concomitant abdominopelvic injuries
  • Penile injuries risk urethral injuries so low threshold for retrograde urethrogram
  • US of penile shaft can be useful in confirming bulbocavernosum haematoma and planning operative management

Genitourinary trauma – External genitalia

• Treatment and disposition
  • Closed testicular contusions managed conservatively
    • Ice, elevation, analgesia, scrotal support and urology follow-up
  • Testicular rupture
    • Immediate surgical drainage and repair
    • Salvage rate up to 90% if treated promptly
  • Penetrating scrotal trauma
    • Immediate surgical exploration

Genitourinary trauma – External genitalia

• Treatment and disposition
  • Penile fractures
    • Immediate urologic consultation as with immediate surgical intervention, erectile function may be spared
  • Traumatic epididymitis
    • Seen days after blow to testis
    • Non-infectious
    • Treated as for non-traumatic epididymitis

Genitourinary trauma – External genitalia

• Penetrating trauma to the penis
  • Surgical consult and usually exploration
  • Loss of penile skin is managed by split skin grafts after denuded penis is clean and sterile
  • Do not reapply avulsed skin as necroses and becomes infected requiring removal later
• Penile amputations
  • Repair and microsurgical reimplantation if deemed viable by urologist
• Zipper injuries
  • Mineral oil and lignocaine +- division of median bar of zipper
• Contusions of perineum or penis
  • Treat conservatively with cold packs, rest and elevation
  • IDC if unable to void

Genitourinary trauma – Special populations

• Elderly
  • Predisposed to complex injuries even with minor mechanisms of injury
  • Higher rates of bladder and urethral injuries
  • Penile prostheses can extrude or rupture predisposing patients to infection and complications of wound healing (esp. in diabetics who are more likely to have prostheses anyway)
  • Obtain urological consult for any patient with even mild trauma in the presence of prosethetics
• Pregnancy
  • Engorgement of the perineum and vulva can lead to increased risk of haemorrhage from penetrating trauma to this region
• Children
  • In prepubescent females, external examination may underestimate trauma
    • Consider consultation for examination under anaesthesia

Last Updated on October 9, 2020 by Andrew Crofton