Chapter 145. Retrograde Urethrography and Cystography

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 the trauma patient is to rule out a partial urethral rupture, complete urethral rupture, or a bladder rupture. 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 iatrogenic or secondary urologic injury.

The evaluation of a traumatically injured patient 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 associated injury. Patients with disruption of the pubic symphysis, pubic rami, or a vertically unstable pelvic fracture have a high incidence of concomitant bladder trauma. Those with an isolated acetabulum, femur, or iliac crest fracture have a low incidence of bladder injury or rupture.13 Unfortunately, the lack of a pelvic fracture does not eliminate the possibility of a bladder or urethral injury.

The most common signs seen in patients 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, inability to void, swelling or ecchymosis of the perineum or penis, a boggy prostate, and a high riding prostate. In the presence of any of these signs, an evaluation of the genitourinary tract is indicated. These assessments should be made early and intervention instituted.

Traditional teaching suggests that urethral catheterization should be avoided if a potential injury to the bladder and/or urethra is suspected. This teaching requires a retrograde urethrogram and cystogram to be performed to rule out any injuries prior to urethral catheterization. A preliminary study suggests that blind urethral catheterization despite a potential injury may be safe.15 Larger and additional studies are required before this change in practice can be safely recommended.

The lower urinary tract in males consists of the urethra and bladder (Figure 145-1). The urethra is divided into the fossa navicularis, the penile urethra, the bulbar urethra, the membranous urethra, and the prostatic urethra based on its 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 is 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 The female urethra is equivalent to the membranous and prostatic (posterior) urethra in the male.6

The periurethral striated sphincter is composed of muscle from the urogenital diaphragm. This muscle layer unites with the distal smooth muscle at the intermuscular incisura. This is frequently seen on the voiding cystourethrogram and may be mistaken for a stricture or posterior urethral valves. The urogenital diaphragm surrounds the membranous urethra and may compress the urethra during voiding or on retrograde flow of contrast.6

The verumontanum and urethral crest protrude into the male prostatic urethral lumen and may extend into the membranous urethra. The prostatic gland ducts, prostatic utricle, ejaculatory ducts, and urethral gland ducts usually do not fill on voiding cystourethrogram; and when visible, filling usually denotes a distal obstruction. These structures, however, may fill during aggressive injection of contrast during the retrograde urethrogram.

On the lateral view of the bladder, the anterior and posterior baseplate (of which the trigone is part) is seen as a diagonal plane sloping downward from posterior to anterior. The bladder neck is visualized at the junction of the anterior one-third and the posterior two-thirds of the plane. Anteriorly, the pubis abuts the baseplate. The fundus of the bladder becomes more dome shaped as it fills with fluid. It may be compressed by the uterus or colon in the midline or on either side.6

The retrograde urethrogram is to be employed in blunt and penetrating traumatic presentations of males when there is any indication of a urethral injury. Indications include penetrating injury when involvement of the lower genitourinary tract is suspected, pelvic fractures, perineal or lower abdominal trauma with gross hematuria, blood at the urethral meatus, inability to void, swelling of the perineum or penis, ecchymosis of the perineum or penis, hematoma of the perineum or penis, a high riding prostate, or a boggy prostate.7,8,13 Other indications include urethral strictures and obstructions, congenital abnormalities, periurethral or prostatic abscess, and fistulae or false passages. In females, it may be indicated if urethral diverticula are suspected.

Retrograde cystography should follow retrograde urethrography, especially in patients who recall having a full bladder at the time of trauma and are later unable to void or have small amounts of bloody urine.9 Retrograde cystograms are nearly 100% sensitive for detecting rupture, provided that adequate distension is accomplished and that postvoid images are obtained.13

There are few contraindications to retrograde urethrography and cystography. However, the patient's overall condition must be taken into consideration. The lifesaving procedures, such as securing an airway and stabilizing life- and limb-threatening injuries, must take precedence. Because septic shock and irreversible renal damage can occur, a relative contraindication in the setting of acute urethritis exists when the suspicion of genitourinary tract trauma is very low. A urethral injury identified on the retrograde urethrogram is the only absolute contraindication to transurethral bladder catheterization and retrograde cystography. Consult a Urologist if, in a patient with pelvic trauma, there is any difficulty in passing a urethral catheter into the bladder. Do not try to advance a catheter against resistance as iatrogenic injury can result. There is a small risk of allergic reactions to the contrast media. Patients with previous reactions should receive nonionic agents and be premedicated with corticosteroids and antihistamines.

• Povidone iodine or chlorhexidine solution
• Sterile gloves
• Sterile drapes
• Viscous lidocaine suspension
• Foley catheter, 5 to 18 French (Table 145-1)
• Brodney clamp
• Contrast material
• 60 mL catheter tip syringe
• Toomey syringe
• Christmas tree adaptor
• Surgical clamp
• Lead apron

A variety of contrast agents are available and may be used to perform retrograde urethrography and cystography. The agents used are specific to each institution. Most commonly used are full strength Hypaque (50% diatrizoate sodium), Renografin-60 (diatrizoate sodium), or Cystografin. Alternatively, the same agents can be diluted with sterile saline in a 1:10 dilution.

Explain the procedure, its risks, and benefits to the patient and/or their representative. While a formal consent is usually not obtained since this is an emergent procedure, document in the medical record that the “risks and benefits were explained to the patient.” If not contraindicated, administer parenteral sedation. Place the patient in a 45° oblique position with their left side on the bed. Flex the left leg at the knee and abduct the hip. Place a radiolucent wedge or rolled towels under the patient to maintain the oblique position. Completely extend the right leg. This is the ideal patient position. The degree of patient mobility and the medical condition may dictate an alteration of this position. In patients with pelvic fractures, all radiographs should be taken with the patient in a supine position.

Prepare the penis and urethra. Clean any dirt and debris from around the penis. Retract the foreskin if the patient is uncircumcised. Apply povidone iodine or chlorhexidine solution to the penis and allow it to dry. Apply sterile drapes to delineate a sterile field. The retrograde urethrogram must be performed under sterile conditions. Insert viscous lidocaine into the urethral meatus to anesthetize the urethra. Do not use lidocaine jelly as this may impede the flow of contrast material. Allow the lidocaine to remain in the urethra for 2 to 4 minutes prior to performing the procedure to provide adequate analgesia.

Obtain a flat plate or KUB (kidney, ureters, and bladder) radiograph. This will be a baseline film for future reference. Carefully examine the radiograph for curvature of the spine, pelvic fractures, fractures of ribs 9 to 12, unilateral or bilateral loss of the normal psoas muscle shadow, or vertebral transverse process fractures. Any of these findings can signify a urinary tract injury. Observe and note any radiopaque material that may be present prior to the injection of contrast material.

The Emergency Physician should dress appropriately for the procedure. Since the Emergency Physician must be near the patient during the procedure and while radiographs are taken, put on a lead apron. Dress in a sterile gown and gloves. A cap and mask are not required.

Foley Catheter Technique

The Foley catheter technique is the preferred method. The Foley catheter causes little or no discomfort, is flexible, and the patient may be able to move if necessary. There is no leakage of contrast from the urethra and onto the patient, which can cause artifacts on the radiographs and make interpretation difficult. An advantage to using the Foley catheter is that it can subsequently be advanced into the bladder to perform the cystogram. The newer types of catheters have two cuffs; one at the tip and the other near the balloon inflation hub of the catheter. The proximal cuff will expand when the pressure in the distal cuff exceeds the maximum safe pressure during cuff inflation. This allows the excess pressure to be directed away from the distal cuff and not cause an iatrogenic urethral injury. There are some disadvantages to this method. The inflated cuff may conceal an injury of the distal urethra at the fossa navicularis. Air bubbles are difficult to eliminate from the catheter. This may impair the flow of the contrast material or produce artifacts due to air in the urethra. Air bubbles in the Foley catheter will alter the integrity of the study. Prime the tubing with contrast before inserting it into the urethra to eliminate any air. Place an X-ray plate under the patient's hips and pelvis.

Insert the catheter into the urethra. Advance it until the cuff is within the fossa navicularis (Figure 145-2A). Inflate the cuff with approximately 3 mL of sterile saline, or to the point that it is snug and does not cause pain to the patient.10 Gently straighten the urethra by directing the tip of the penis toward the dependent shoulder or nipple and over the thigh. Avoid traction on the penis or the Foley catheter as it tends to narrow the urethra and/or dislodge the catheter. Attach a contrast-filled syringe to the proximal end of the Foley catheter (Figure 145-2A). Gently inject 50 to 60 mL of contrast material over 5 to 10 seconds.

Obtain a plain radiograph at or near the end of the injection. Have the film developed and review the image. The entire urethra should be visible in a lateral projection. Repeat the procedure if this is not achieved. Allow the contrast to drain from the urethra through the Foley catheter and into a container. Deflate the cuff and remove the catheter from the urethra. Obtain an additional plain radiograph of the pelvis as a washout image. Have the film developed and review the image for any abnormalities in the urethra. Although not necessary, fluoroscopy may aid in obtaining an adequate study.10

Great care should be taken so as not to allow any contrast to leak out of the catheter or urethra. Any spill of contrast material will cause distortions on the radiographs. The contrast may also cause skin irritation. It should be wiped and rinsed off the skin immediately if this occurs.

Syringe Technique

If a proximal urethral injury is suspected, the alternative method is to use a 60 mL catheter-tipped Toomey syringe or a 60 mL syringe with a Christmas tree adaptor. Because it is not flexible and cannot be fixed inside the penis, the syringe must be held in place at all times during the procedure. The penile shaft must also be held to secure the tip of the syringe inside the urethra. There is a significant chance of contrast leakage from the urethra using this technique.

Clear, prep, and drape the penis as described previously. Place an X-ray plate under the patient's hips and pelvis. Grasp and cradle the patient's penis with the nondominant hand. Insert the tip of the contrast-filled syringe into the urethra. Firmly squeeze the glans penis between the thumb and the index and long fingers (Figure 145-2B). This will secure the catheter tip within the fossa navicularis. Do not squeeze the shaft of the penis with middle, ring, or little fingers as this can occlude the urethra. Gently straighten the urethra by directing the tip of the penis toward the dependent shoulder or nipple and over the left thigh. The remainder of the procedure is as described above in the Foley catheter section.

Brodney Clamp Technique

The Brodney clamp is a cage with rubber feet that clamp behind the corona of the glans.10 In the center of the device there is a blunt-tipped obturator that inserts into and occludes the urethral meatus. It may be used instead of a Foley catheter or 60 mL syringe for the procedure. The advantage of this device is that both the fossa navicularis and the distal urethra are visible on the radiograph. Air bubbles are easily eliminated from the obturator. The disadvantages of the clamp are that it is not flexible and it is heavy. It must be held during the procedure and fluoroscopy is impossible. If the patient moves, the clamp tends to dislodge. The clamp is difficult to use in older children, adolescents, adults, and in the presence of a phimoses.10 Brodney clamps are usually not stocked in the Emergency Department and may be difficult to obtain in a timely manner.

Clean, prep, and drape the penis as mentioned previously. Insert the blunt-tipped obturator of the clamp into the urethra. Rotate the feet of the clamp so that they are grasping the coronal sulcus of the penis. These should not be so tight as to occlude the urethra ventrally. The remainder of the technique is as described in the Foley catheter section.

Any abnormalities in the retrograde urethrogram, such as extravasation of the contrast from the urethra or evidence of strictures, should prompt an urgent consult by a Urologist. If the study is normal, the retrograde cystogram should be performed. Gently advance and fully insert a Foley catheter into the bladder (Figures 145-3A & B). Inflate the cuff at the tip of the Foley catheter (Figure 145-3B). Gently pull on the Foley catheter to lodge the cuff at the bladder neck (Figure 145-3C). Attach a 60 mL catheter-tipped syringe, without the plunger, to the Foley catheter. Pour contrast material into the syringe and let it drain by gravity into the bladder to overdistend the bladder. Continue to allow contrast to fill the bladder until 300 to 400 mL of contrast material is in the bladder of an adult or any child older than 11. In younger children, the instilled volume (in mL) is estimated by the formula weight (kg) × 10 in children <1 year of age, (age in years + 2) × 30 in children >1 year of age, or to the point of initiating a bladder contraction.11 If a bladder contraction occurs, refill the bladder to the volume that initiated the contraction and clamp the Foley catheter. Volumes less than these can result in a false-negative study. After the contrast is instilled, clamp the Foley catheter with a hemostat.

Obtain two plain radiographs. These are the anteroposterior (AP) and the oblique, or the lateral, views of the pelvis. Evaluate the radiographs for proper bladder filling with contrast and for extravasation of contrast. Release the hemostat and allow the contrast to drain out of the bladder through the Foley catheter and into the container. Obtain another AP radiograph of the pelvis (washout film). This film is often helpful in picking up obscured areas of extravasation not visible on the initial film. Review the radiographs for intraperitoneal and extraperitoneal bladder rupture.

A novel approach to the use of plain radiography may be the use of computed tomography (CT) retrograde urethrography.16 Although this case report will not change current clinical practice, it may be an alternative in the trauma patient requiring a CT scan of the pelvis and may reduce the time for patient evaluation.

The technique is similar to the Foley catheter technique described previously. Place the Foley catheter into the distal urethra, inflate the balloon, and inject 10 mL of contrast material. Clamp the Foley catheter. Obtain a thin-cut CT scan through the pelvis, perineum, and penis. Instruct the CT technician to run a computerized three-dimensional reconstruction of the CT scan. Evaluate the CT reconstruction for contrast extravasation, urethral occlusion, and/or urethral narrowing.

In a normal retrograde urethrogram, the entire urethra should be visible. Some of the contrast material should also be seen within the bladder. Extravasation of contrast from the urethra will appear as a flame-like density outside the urethra. A partial urethral disruption will show extravasation of contrast as well as contrast within the bladder. In a complete urethral disruption, no contrast material will be visible within the bladder. Occasionally, contrast material may be seen in the venous plexus of the penis due to forceful injection of contrast into the urethra. This is a common phenomenon and should not be mistaken for extravasation. The venous flush will clear spontaneously on a postvoid film.

In the evaluation of the retrograde cystogram, intraperitoneal and extraperitoneal bladder injuries can be differentiated. The extravasation of the contrast material that appears as a flame-like projection confined to the pelvis constitutes the extraperitoneal injury. In patients with intraperitoneal injuries, the contrast tends to outline the intraperitoneal organs. This differentiation is important because each requires a different treatment. All intraperitoneal injuries are managed surgically whereas some extraperitoneal injuries can be managed with Foley catheter drainage or suprapubic cystostomy (Chapter 144).7

Because of the hypertonicity of the contrast material and urethral stretching, patients may experience burning and dysuria. After a normal study, ensure that the patient is well hydrated. The flow of urine will wash the contrast out of the bladder and urethra.

Several complications can result from retrograde urethrography and cystography. Mechanical trauma from the catheter or balloon can result in bleeding, urethral injury, bladder perforation, and the conversion of a partial urethral disruption into a complete urethral disruption. Adverse reactions to the contrast agents can occur.17–20 These may be due to local reactions or absorption of contrast into the blood. These reactions can range from itching and skin rashes to anaphylaxis and Stevens–Johnson syndrome. Treat any adverse reactions as any other allergic or hypersensitivity reaction.

The retrograde urethrogram should be performed in any male with a pelvic fracture, lower abdominal trauma with gross hematuria, inability to void, hematoma of the perineum, or a high riding or boggy prostate on physical examination. The cystogram should follow to evaluate potential bladder injuries. The cystogram is used to evaluate and differentiate intraperitoneal and extraperitoneal bladder injuries.

Retrograde urethrography and cystography are diagnostic procedures that are easy to perform and have the potential to avoid major complications related to urine leakage. Both of these procedures are safe and simple to perform. With basic equipment, invaluable information can be collected with very little time investment. The early recognition of disruption of the lower genitourinary tract can prevent significant morbidity.