Blunt abdominal trauma: posterior urethral injury

Case contribution: Dr Radhiana Hassan

Clinical:

  • A 20 years old man, involved in MVA (motorbike versus car)
  • On arrival to ED, BP=150/54mmHg, PR=105 bpm and GCS=10/15
  • CBD gross hematuria.
  • CT scan brain shows right extradural hemorrhage at temporal region with fracture at greater wing of right sphenoid (images not shown)
  • Drop of hemoglobin during admission; Hb: 14 to 11.3 g.dL
  • Blocked CBD, unable to pass urine and unable to reinsert new CBD.
  • SPC done under ultrasound guidance
Contrast-enhanced CT abdomen pelvis in axial plane soft tissue window
Selected CT scan at level of urinary bladder in axial planes, soft tissue window
CT scan pelvis axial plane bone windows
CT scan at urinary bladder region post contrast delayed images in axial plane soft tissue window

CT scan findings:

  • No organ injury seen. No hemoperitoneum
  • Blood clots are seen in the urinary bladder¬† (white arrows)
  • Air and CBD balloon within the bladder (yellow arrow)
  • Soft tissue streakiness at perineum (red arrows)
  • Diasthesis of left sacroiliac joint and symphysis pubis (blue arrow)
Descending urethrogram examination

Flouroscopy examination:

  • Symphysis pubis diasthesis as noted on previous CT scan (blue arrow)
  • Contrast infused via SPC
  • Urinary bladder is well distended, normal outline
  • No extravasation of contrast seen
  • Patient unable to pass urine
  • Ascending urethrogram was planned but abandoned due to failure to cannulate the urethra

Cystoscopy examination done in OT

  • Membranous urethral stricture almost 70% circumferentially
  • SPC out of urinary bladder with encrusted tip of the catheter.
  • SPC removal and urethral dilatation done

Diagnosis: Posterior urethral injury 

Discussion:

  • Injuries to the posterior urethra are most often related to motor vehicle accident and pelvic fractures (72%). Injury to the posterior urethra exclusively occurs in pelvic fractures with disruption of the pelvic ring.
  • During deceleration impact injury, the severe shearing forces needed to fracture the pelvis are transmitted to the attachment of the perineal membrane and puboprostatic ligaments
  • The highest risk of urethral injury is in straddle fractures with a concomitant diastasis of the sacroiliac joint. Displaced fractures of the inferomedial pubic bone and pubic symphysis diastasis, together with their degree of displacement, are independent predictors of urethral injury.
  • Most posterior injuries occur at the bulbomembranous junction, distal to the external urethral spinchter.
  • Posterior urethral injuries can result in significant delayed morbidity. Strictures, incontinence and erectile dysfunction (ED) are well-recognized associated problems that interfere with the quality of life.
Author: radhianahassan