Retrograde Urethrography

Used almost exclusively in men, retrograde urethrography requires instillation or injection of a contrast medium into the urethra and permits visualization of its membranous, bulbar, and penile portions.

Although visualization of the anterior portion of the urethra is excellent with this test alone, the posterior portion is more effectively outlined by retrograde urethrography in tandem with voiding cystourethrography.

Purpose

• To diagnose urethral strictures, outlet obstruction, diverticula, and congenital anomalies
• To assess urethral lacerations or other trauma
• To assist with follow-up examination after surgical repair of the urethra

Patient preparation

• Explain to the patient that this test diagnoses urethral structural problems. Inform him that he needn't restrict food or fluids.
• Describe the test, including who will perform it, where it will take place, and its expected duration (about 30 minutes).
• Inform the patient that he may experience some discomfort when the catheter is inserted and when the contrast medium is instilled through the catheter.
• Tell him that he may hear loud, clacking sounds as the X-ray films are made.
• Make sure the patient or a responsible family member has signed a consent form if required.
• Check the patient's history for hypersensitivity to iodine-containing foods, such as shellfish, or contrast media.
• Just before the procedure, administer any prescribed sedatives and instruct the patient to void before leaving the unit.

Equipment

Penile clamp, 50-ml syringe with tapered universal adapter, indwelling urinary catheter, 1" (2.5-cm) roller gauze, contrast medium (half-strength preparation)

Procedure and posttest care

For men

• The patient is placed in a recumbent position on the examining table. Anteroposterior exposures of the bladder and urethra are made, and the resulting films studied for radiopaque densities, foreign bodies, or stones.
• The glans and meatus are cleaned with an antiseptic solution. The catheter is filled with the contrast medium before insertion to eliminate air bubbles.
• Although no lubricant should be used, the tip of the catheter may be dipped in sterile water to facilitate insertion.
• The catheter is inserted until the balloon portion is inside the meatus; the balloon is then inflated with 1 to 2 ml of water, which prevents the catheter from slipping during the procedure.
• The patient then assumes the right posterior oblique position, with his right thigh drawn up to a 90-degree angle and the penis placed along its axis. The left thigh is extended.
• The contrast medium is injected through the catheter. After three­fourths of the contrast medium has been injected, the first X-ray film is exposed while the remainder of the contrast medium is being injected. Left lateral oblique views may also be taken.
• Fluoroscopic control may be helpful, especially for evaluating urethral injury.

For women and children

• In women, this test may be used when urethral diverticula are suspected. A double-balloon catheter is used, which occludes the bladder neck from above and the external meatus from below.
• In children, the procedure is the same as for adults except that a smaller catheter is used.

For all patients

• Watch for chills and fever related to extravasation of contrast medium into the general circulation for 12 to 24 hours after retrograde urethrography. Also observe for signs of sepsis and allergic manifestations.

Precautions

• Retrograde urethrography should be performed cautiously in patients with urinary tract infection.

Normal Findings

The membranous, bulbar, and penile portions of the urethra - and occasionally the prostatic portion - appear normal in size, shape, and course.

Abnormal findings

Radiographs obtained during retrograde urethrography may show the following abnormalities: urethral diverticula, fistulas, strictures, false passages, calculi, and lacerations; congenital anomalies, such as urethral valves and perineal hypospadias; and rarely, tumors (in less than 1% of patients).

Interfering factors

• None significant