Lower Urinary Tract Trauma

Includes 2020 AUA Guideline Notes on Urotrauma

See Upper Urinary Tract Trauma Chapter Notes

Bladder Injury

• Pathogenesis
  • Penetrating trauma
    • The bladder is generally protected from external trauma because of its deep location in the bony pelvis
  • Blunt trauma
    • Most blunt bladder injuries are the result of rapid-deceleration motor vehicle collisions, but many also occur with falls, crush injuries, assault, and blows to the lower abdomen
    • Bladder injuries that occur with blunt trauma are rarely isolated injuries
      • The most common associated injury is pelvic fracture, but pelvic fracture is not often associated with with bladder injury
        • 83-95% of bladder injuries are associated with pelvic fractures
        • 5-10% of pelvic fractures are associated with bladder injury
  • Iatrogenic
    • Obstetric and gynecologic complications are the most common causes of bladder injuries during open surgery
  • Bladder rupture can occur into the peritoneal cavity (intraperitoneal bladder rupture) or outside the peritoneal cavity (extraperitoneal rupture).
    • Bladder injuries are:
      • Extraperitoneal in ≈60%
      • Intraperitoneal in ≈30%
      • Both intraperitoneal and extraperitoneal in ≈10%
    • Extraperitoneal bladder injury
      • Usually associated with pelvic fracture
    • Intraperitoneal bladder injury
      • Can be associated with pelvic fracture but are more commonly due to penetrating injuries or burst injuries at the dome by direct blow to a full bladder.
• Grading (AAST Bladder Injury Scale)
  • Grade I
    • Contusion, intramural hematoma
    • Partial thickness laceration
  • Grade II
    • Extraperitoneal bladder wall laceration <2 cm
  • Grade III
    • Extraperitoneal (>2cm) or intraperitoneal (<2cm) bladder wall laceration
  • Grade IV
    • Intraperitoneal bladder wall laceration >2cm
  • Grade V
    • Intraperitoneal or extraperitoneal bladder wall laceration extending into the bladder neck or ureteral orifice (trigone)
  • *Advance one grade for multiple lesions up to grade III
• Diagnosis and Evaluation
  • History and physical exam
    • Indicators of potential bladder rupture (12):
      1. Gross hematuria
         • Most common indicator of bladder injury
         • A limited number of pelvic fracture patients with bladder injuries will present with microscopic hematuria
      2. Lower abdominal bruising
      3. Abdominal distention
      4. Suprapubic pain
      5. Muscle guarding and rigidity
      6. Inability to void
      7. Low urine output
      8. Diminished bowel sounds
      9. Pubic symphysis diastasis
      10. Obturator ring fracture displacement >1 cm
      11. Increased creatinine and BUN (secondary to peritoneal absorption of urine)
      12. Intraperitoneal low density free fluid on abdominal imaging (urinary ascites)
  • Imaging
    • Indications for cystography in stable patients
      • 2020 AUA Guidelines
        • Absolute (1):
          1. Gross hematuria and pelvic fracture
        • Relative (2):
          1. Gross hematuria and a mechanism concerning for bladder injury
          2. Pelvic ring fractures and clinical indicators (see above) of bladder rupture
             • The vast majority of bladder injuries are associated with pelvic fractures because the bladder is well protected within the pelvis, however, pelvic fracture alone does not warrant radiologic evaluation of the bladder
      • Campbell's 11th edition
        • Absolute (2):
        1. 1. Gross hematuria with pelvic fracture
           2. Penetrating injuries with any degree of hematuria
        • Relative (2):
        1. 1. Blunt trauma with gross hematuria without pelvic fracture
           2. Microscopic hematuria with pelvic fracture
    • Modality: retrograde cystography (CT or plain film)
      • Critical as it can determine the presence of an injury and whether it is intraperitoneal or extraperitoneal.
      • Plain film and CT cystography have similar specificity and sensitivity, and are both highly accurate for the diagnosis of bladder rupture
      • Technique
        • The bladder should be filled in cooperative and conscious patients to a sense of discomfort and otherwise to 300-350 mL
          • False-negative studies have been reported with retrograde instillation of only 250 mL.
          • In CT cystography, dilution of the contrast (1:6) is mandatory because undiluted contrast is so dense that the CT quality is compromised by scatter artifact.
          • Clamping a Foley catheter to allow excreted IV-administered contrast to accumulate in the bladder is not appropriate.
        • With plain film cystography, a minimum of 2 views are required, the first at maximal fill and the second after bladder drainage.
        • Drainage films are not required after CT cystography because the retrovesical space can be well visualized with axial images.
      • Cystography will demonstrate:
        • Extraperitoneal extravasation: dense, flame-shaped collection of contrast material in the pelvis
          • See Figure
          • See Case
        • Intraperitoneal extravasation: contrast material outlines loops of bowel and/or the lower lateral portion of the peritoneal cavity
          • See Figures
        • The amount of extravasation is not always proportional to the extent of bladder injury.
• Management
  • If blood is noted at the meatus or the catheter does not pass easily, retrograde urethrography should be performed first because urethral injuries occur concomitantly in 10-30% of patients with bladder rupture
  • Based on extraperitoneal vs. intraperitoneal
    • Uncomplicated extraperitoneal bladder ruptures: large-bore (22-Fr) Foley catheter left in place 2-3 weeks
      • In the setting of significant concurrent injuries, it is acceptable to leave the catheter in longer.
      • Campbell’s 11th edition: if a pelvic hematoma is present, antimicrobial agents are started on the day of injury and continued for at least 1 week to prevent infection of the hematoma
      • Consideration for open repair may be appropriate in those patients with non-healing bladder injuries who are unresponsive to Foley catheter drainage >4 weeks.
      • Follow-up cystography
        • Should be done to confirm that the injury has healed with catheter drainage
    • Intraperitoneal bladder rupture: prompt surgical repair
      • Failure to repair intraperitoneal bladder injuries can result in peritonitis (from translocation of bacteria from the bladder to the abdominal cavity), sepsis, and other serious complications
      • Repair may need to be delayed in the unstable patient
      • Campbell’s 11th edition: in patients with intraperitoneal rupture, antimicrobial agents are administered for 3 days in the perioperative period only
      • Follow-up cystography
        • Should be done 7-10 days after surgery in complex repairs
        • May not be necessary in more simple repairs
  • Indications for immediate surgical repair of bladder
    • AUA (7)§: Immediate Bladder Repair NOVA
      1. Intraperitoneal bladder rupture
      2. Exposed Bone spicules in the bladder lumen
      3. Concurrent Rectal injury; may lead to fistula formation to the ruptured bladder
      4. Bladder Neck injuries; may not heal with catheter drainage alone and repair should be considered
      5. Patient undergoing Open reduction internal fixation; to reduce risk of infection to hardware)
      6. Concurrent Vaginal injury; may lead to fistula formation to the ruptured bladder
      7. Patient undergoing repair ofAbdominal injuries, consider performing bladder repair for extraperitoneal bladder injury given that the typical bladder repair can be performed quickly and with little morbidity.
    • Additional indications for immediate repair of bladder injury (Campbell’s 11th edition):
      1. Penetrating or iatrogenic non-urologic injury
      2. Inadequate bladder drainage or clots in urine
      3. Open pelvic fracture
  • Surgical management
    • To repair the bladder, the anterior bladder wall is entered, and the tear is closed intravesically with absorbable suture. The perivesical pelvic hematoma should not be disturbed.
    • The integrity of the bladder neck and ureteral orifices should be confirmed and repair considered if injured
    • Following surgical repair for bladder injuries, urethral catheter drainage alone without suprapubic (SP) cystostomy is recommended
      • Studies have shown no advantage of combined SP and urethral catheterization
      • Exceptions in which combined SP and urethral catheterization may be considered (3):
        1. Patients requiring long-term catheterization, such as those with severe neurological injuries (i.e., head and spinal cord), those immobilized due to orthopedic injuries
        2. Complex bladder repairs with tenuous closures
        3. Significant hematuria