Chapter 176: Retrograde Urethrography and Cystography

INTRODUCTION

Urinary tract injuries may result from blunt trauma, penetrating trauma, urologic procedures, or may arise spontaneously.^1-14 Bladder injuries occur in up to 15% of pelvic fractures.^1-3 Associated urethral injuries occur in up to 11% of males and up to 6% of females.^1-3 The role of retrograde urethrography and cystography in evaluation of the trauma patient is to rule out a partial urethral rupture, complete urethral rupture, and/or bladder rupture.^15-17 On initial presentation to the Emergency Department, there are clear indications for performing these procedures. The importance of proper training in these techniques must be stressed to avoid secondary injury.

The evaluation of trauma patients should include, if appropriate, an assessment of the bony pelvis and the genitourinary system. The identification of a pelvic fracture must be followed by an examination of the lower genitourinary tract to rule out an associated injury. Patients with disruption of the pubic symphysis or pubic rami or with a vertically unstable pelvic fracture have a high incidence of concomitant bladder trauma.¹³ Patients with an isolated acetabulum, femur, or iliac crest fracture have a low incidence of bladder injury or rupture.¹³ The lack of a pelvic fracture does not eliminate the possibility of a bladder or urethral injury. The most common signs seen with genitourinary tract injury are gross hematuria (82%) and abdominal tenderness (62%).⁴ Other signs of genitourinary tract injury include blood at the urethral meatus, the inability to void, swelling or ecchymosis of the perineum or penis, a boggy prostate, and a high-riding prostate. An evaluation of the genitourinary tract is indicated in the presence of any of these signs. These assessments should be made early and interventions instituted immediately.

Traditional teaching suggests that urethral catheterization should be avoided if a potential injury to the bladder and/or urethra is suspected. This teaching requires performance of a retrograde urethrogram and cystogram to rule out any injuries prior to urethral catheterization. A preliminary study suggests that blind urethral catheterization, despite a potential injury, may be safe.¹⁸ Additional large multicenter studies are required before this change in practice can be safely recommended. The guidelines do allow for a single attempt at catheter drainage if exceptional circumstances indicate a need for monitoring.¹⁴

ANATOMY AND PATHOPHYSIOLOGY

The lower urinary tract in males consists of the urethra and bladder (Figure 176-1). The urethra is divided into the fossa navicularis, the penile urethra, the bulbar urethra, the membranous urethra, and the prostatic urethra based on anatomic location. The bladder neck opens into the trigonal canal and funnels into the bladder. The male posterior urethra is 5.0 to 5.5 cm long, fixed to the urogenital diaphragm, and the area most susceptible to injury.^2,5 The female urethra is short, not rigidly fixed to the pubis or pelvic floor, mobile, and much less susceptible to injury.^3...