Smiths General Urology, Seventeenth Edition (LANGE Clinical Medicine)

Authors: Macfarlane, Michael T.

Title: Urology, 4th Edition

Copyright 2006 Lippincott Williams & Wilkins

> Table of Contents > Part One - Chief Presentations > Chapter 13 - Trauma

Chapter 13

Trauma

Traumatic injuries to the genitourinary tract represent about 10% of all injuries seen in the emergency room. The urgency of the patient's overall clinical condition will dictate how a diagnosis will be made. Care must be taken not to overlook significant urologic injuries during the commotion of a major trauma emergency. The initial assessment of major trauma will focus on control of hemorrhage and shock. Resuscitative efforts will usually require placement of intravenous (IV) lines and a Foley catheter. This early urologic intervention will be the first problem faced. Careful examination of the urethral meatus for the presence of blood is essential before Foley catheter placement. Blood at the meatus indicates urethral injury. A retrograde urethrogram can be performed to assess the extent of urethral injury before catheterization. The second urologic challenge will be to assess for renal injury in any major blunt abdominal trauma or penetrating trauma to the upper abdomen. This can be accomplished quickly by a double-dose (150 mL Renografin) bolus intravenous urogram (IVU) performed on the trauma table or, if possible, by computed tomography (CT) scan. Obtain urologic consultation before opening the abdomen.

Initial Urologic Assessment

History

A detailed history of the traumatic event from the patient or eyewitnesses can help predict the type of injury.

Physical Examination

Injury to the bladder or urethra would be suggested by evidence of a pelvic fracture, blood at the urethral meatus, or superior displacement of the prostate on digital rectal examination. Diagnostic studies include

• Urinalysis

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• Retrograde urethrogram if blood at the meatus

• CT scan with IV contrast

• Double-dose (150 mL) bolus IVU (for unstable patients)

Renal Injury

The kidney is the organ most commonly involved in urinary system trauma. Microscopic or gross hematuria indicates injury to the urinary system. However, 10% to 25% of significant renal injuries will present without hematuria, and these are most often major injuries of the renal pedicle. Renal injuries are properly separated into two major groups for diagnostic purposes: those caused by penetrating trauma (20%) and those caused by blunt trauma (80%).

Penetrating Renal Trauma

Penetrating trauma almost always results in surgical exploration because of other significant injuries (e.g., liver, small bowel, stomach, colon, and spleen). Gunshot and stab injuries are the most common causes. Renal injury can often be overlooked in the face of more urgent problems. Absence of hematuria does not rule out renal injury. A double-dose IVU can be performed on the operating table if no prior radiologic studies have been performed. CT scan with IV contrast should be obtained before going to the operating room if the patient's condition allows. Radiographic evidence of unilateral nonfunction, extravasation, suspected laceration, or large perirenal hematoma requires renal arteriography. Unfortunately, renal exploration of penetrating trauma often results in partial or total nephrectomy.

Blunt Renal Trauma

Blunt trauma requires considerable diagnostic effort to fully assess the extent of injury and determine proper management. Most blunt renal injuries result from rapid deceleration, as in a motor vehicle accident or a fall. Hematuria will usually be present, but its absence does not rule out renal injury. Patients with gross hematuria or microscopic hematuria [>5 red blood cells (RBCs) per high power field (hpf)] with shock should undergo imaging studies, usually a CT with IV contrast. Fracture of a lumbar transverse process or lower rib should raise suspicion of renal injury.

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Classification of Renal Injury

Staging of renal trauma should begin with a double-dose (150 mL) IVU if the patient is hemodynamically unstable. This will effectively stage 85% of renal injuries. A CT scan with IV contrast is preferred if the patient is stable. Nonvisualization requires immediate renal arteriography without delay to evaluate for renal pedicle injury.

Management of Blunt Renal Trauma

• Minor renal injury accounts for most cases and should be treated conservatively (bedrest until urine grossly clears, monitoring of vital signs and hematocrit).

• Renal pedicle injuries demand immediate surgery (revascularization or nephrectomy).

• Other major renal injuries can also be treated nonsurgically in most instances with careful monitoring, observation, and antibiotic coverage. Even grade IV lacerations can be cautiously monitored if the patient is stable and blood loss is limited.

Late Complications of Conservative Management

• Hypertension

• Abscess formation within urinoma or hematoma

• Delayed hemorrhage, which may occur 1 to 4 weeks after injury

• Hydronephrosis

• Arteriovenous fistula

Ureteral Injury

Ureteral injury is usually the result of surgical mistakes resulting in ligation or transection; however, ureteral injury occasionally

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Management of Ureteral Injury

• Immediately re-explore and repair with watertight tension-free anastomoses is the rule.

• Attempt to pass a retrograde or anterograde ureteral stent with incomplete or partial injuries.

• Options for lower ureteral injury:

  • Antirefluxing reimplantation (first choice)

  • Psoas hitch

  • Boari bladder tube flap

• Options for midureteral injuries:

  • Primary ureteroureterostomy

  • Transureteroureterostomy (TUU)

• Options for upper ureteral injuries:

  • Primary ureteroureterostomy

  • Replacement with ileal segment

  • Autotransplantation into pelvis

  • Nephrectomy

• Stent with soft double-J ureteral catheters generally recommended.

• Extraperitoneally drain all areas of possible extravasation.

• Antibiotic coverage should be given.

Bladder Injury

Bladder injury is caused by either penetrating trauma (usually gunshot) or blunt trauma (usually a motor vehicle accident). Blunt trauma resulting in lower urinary tract injury is usually the result of a pelvic fracture. Pelvic fractures have an associated lower urinary tract injury in about 15% of cases, with most involving the bladder. Fractures of the pubic rami are the most common type associated with lower urinary tract injury, with 20%

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Diagnosis of Bladder Injury

Diagnosis requires a distention cystogram with 300 to 400 mL dilute contrast and postdrainage films to detect small retrovesical extravasation. A false negative rate as high as 80% has been noted when less than 250 mL contrast is used. Excretory urography will only detect 15% of bladder injuries and is therefore an inadequate workup. A teardrop bladder deformity suggests a massive pelvic hematoma.

Management of Penetrating Bladder Injury

Prompt surgical exploration should be performed. Integrity of the lower ureters should be confirmed with 5 mL indigo carmine IV. Appearance of blue from the ureteral orifices should occur within 10 minutes. Suprapubic drainage should be provided by a large diameter (26 30 F) Malecot catheter and Penrose drains placed around the bladder. One should resist the temptation to explore a large pelvic hematoma.

Management of Blunt Bladder Injury

Intraperitoneal ruptures should be surgically explored with repair of the bladder injury. Placement of a suprapubic urinary catheter (24 30 F Malecot catheter) should be considered.

Extraperitoneal ruptures can be managed conservatively with simple Foley catheter drainage (20 22 F) and close monitoring in most instances. The catheter can generally be removed in 7 to 10 days but only after a satisfactory follow-up cystogram.

Urethral Injury

Urethral injury is uncommon in males and even rarer in females. It typically results from either pelvic fractures or straddle type injuries. Anatomic localization to the posterior or anterior urethra aids in management.

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Posterior Urethral Injuries

Posterior urethral injuries are usually the result of blunt trauma with a pelvic fracture, especially when involving the pubic rami. The primary site of injury is the prostatomembranous junction. The prostate is sheared from the membranous urethra that is anchored in the urogenital diaphragm. Patients present with blood at the meatus in more than 80% of cases, and digital rectal examination may reveal a high pelvic prostate. A retrograde urethrogram will demonstrate pelvic extraperitoneal extravasation above the urogenital diaphragm and usually also below. Management consists of suprapubic urinary diversion by open cystostomy with definitive repair in 3 to 6 months. Primary endoscopic realignment may be attempted if it can be accomplished easily and without disturbing the pelvic hematoma. An associated bladder rupture occurs in 20% of cases and should be repaired primarily without delay. Complications include stricture, impotence, and incontinence. Delayed primary repair of urethral injuries has been reported to decrease impotence and incontinence.

Anterior Urethral Injuries

Anterior urethral injuries are most often caused by a straddle fall or perineal trauma. Crushing of the bulbar urethra against the inferior margin of the symphysis pubis results in contusion or laceration. This type of injury accounts for less than 10% of all urethral injuries. Patients typically present with a bloody urethral discharge and a perineal bruise (butterfly hematoma). A retrograde urethrogram may demonstrate extravasation below the urogenital diaphragm. Management requires suprapubic drainage for 1 to 3 weeks if extravasation was noted. The catheter may be removed in 1 week if a voiding cystourethrography (VCUG) is normal. Occasionally, an extensive perineal hematoma with urinary extravasation will require primary surgical drainage. Stricture is the most common complication.

Penile Injuries

Penile injuries are usually the result of penetrating trauma from bullets or stab wounds or strangulation trauma from constricting rings. Fracture of the corpora cavernosa can occur from blunt trauma during a state of tumescence. The extent of injury is often readily apparent from physical examination. If Buck's fascia is

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Management of Penile Injuries

• Avulsion of penile skin distal to the injury should be removed and followed by a split-thickness skin graft.

• Penetrating penile injury deep to Colles' fascia should be explored.

• Rupture of corpora cavernosa is generally explored with evacuation of clots, debridement, and repair of the tunica albuginea.

Scrotal and Testicular Injury

Injuries to the scrotum are from either penetrating trauma (e.g., gunshot or stab wounds), blunt trauma, or burns. The severity of the injury will dictate the appropriate management; however, one should always suspect underlying testicular injury.

Penetrating Trauma

Management of scrotal lacerations must be guided by a thorough knowledge of the tissue layers involved.

Blunt Scrotal Trauma

Whenever a history of minor scrotal trauma is given in the setting of swelling and pain, be sure to rule out testicular torsion or epididymitis. This can often be resolved by urinalysis. Pyuria suggests

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Burn Injury

Burn injury to the genitalia requires careful monitoring because the extent of injury is often greater than is initially apparent. Management consists of debridement of devitalized tissue and topical therapy with silver sulfadiazine. A Foley catheter or suprapubic tube should be placed in extensively burned patients.