Perineal Trauma

Perineal trauma includes blunt, penetrating, crush and impalement injuries involving the anus, rectum, genitalia, urethra, vagina, pelvic floor and surrounding soft tissues.

High energy pelvic fractures may combine massive haemorrhage with rectal and genitourinary injury, producing a major risk of pelvic sepsis.

Management is determined by haemodynamic stability, contamination, sphincter injury, rectal involvement and associated pelvic or urinary tract injury.

Inspect for:

• Perineal wounds
• Active haemorrhage
• Rectal or vaginal bleeding
• Faecal contamination
• Blood at the urethral meatus
• Scrotal or vulval haematoma
• Pelvic instability
• Loss of anal sphincter continuity
• Neurological deficit

Blood at the urethral meatus, inability to void or a high risk pelvic fracture should raise concern for urethral injury.

Initial assessment follows major trauma priorities with rapid haemorrhage control.

CT abdomen and pelvis with IV contrast: defines pelvic and associated visceral injury in a stable patient.

When urethral injury is suspected, perform retrograde urethrography before repeated urethral catheter attempts.

Proctoscopy or examination under anaesthesia is useful when rectal injury is suspected but not adequately defined by imaging.

Control life threatening haemorrhage first using pelvic stabilisation, blood product resuscitation, packing or angioembolisation according to the injury pattern.

Give broad antibiotics for contaminated open perineal or rectal injury.

A practical regimen is:

Piperacillin tazobactam 4.5 g IV every 8 hours by extended infusion, adjusted for renal function.

Perform aggressive irrigation and debridement of devitalised contaminated tissue while preserving viable sphincter, genital and neurovascular structures whenever possible.

Rectal injury

Intraperitoneal rectal injury is treated according to colon trauma principles with primary repair or resection according to tissue destruction and physiology.

Significant extraperitoneal penetrating rectal injury commonly requires proximal faecal diversion, particularly when destructive injury, pelvic fracture or substantial soft tissue contamination is present. Routine presacral drains and distal rectal washout are unnecessary in nondestructive injuries.

Urethral injury

Do not repeatedly pass a urethral catheter through a suspected complete posterior urethral disruption.

Establish bladder drainage, commonly using suprapubic cystostomy when safe urethral catheterisation or early realignment is not appropriate. Definitive urethral reconstruction is usually delayed until pelvic healing and scar maturation.

Anal sphincter injury

Clearly identify damaged internal and external sphincter ends during debridement when possible.

A clean accessible acute sphincter injury may undergo primary repair. Gross contamination, tissue loss or unstable physiology may require temporary diversion and delayed reconstruction.

Open pelvic fractures with rectal injury require close coordination between trauma, colorectal, orthopaedic and urological teams. Repeat debridement is often necessary because devitalisation evolves after the initial operation.