Approach Considerations
The diagnosis of urethral strictures is based on a suggestive history, findings on physical examination, and radiographic or endoscopic visualization. The entire urethra, both proximal and distal to the strictured area, must be evaluated endoscopically and/or radiographically prior to any surgical intervention. [22]
Imaging Studies
Radiographic evaluation of the urethra with contrast studies is best achieved by retrograde urethrogram (RUG), or antegrade cystourethrogram if the patient has an existing suprapubic catheter. Oftentimes strictures are initially diagnosed with cystoscopy. However, cystoscopy can usually only determine the presence of stricture but cannot accurately delineate the length of the stricture because the proximal extent of stricture cannot be visualized through the small lumen.
Retrograde urethrograms and antegrade cystourethrograms are usually obtained through the radiology department, although the urologist can perform them directly. These studies can be used to diagnose and define the extent of the urethral stricture. Accurately documenting the extent and location of the stricture is important so that the most effective treatment options can be offered to the patient.
The technical aspects of a retrograde urethrogram involve placing a nonlubricated 8F or 10F urethral catheter into the fossa navicularis and inflating the balloon with 1-3 mL of sterile water until the balloon occludes the urethral lumen. This is done with the patient in an obliqued position. Adequate positioning is known when the obturator foramen on the patient's inferior side cannot be seen. Doing the imaging without the patient in the proper position can result in underestimation of stricture length.
A scout film is obtained. Approximately 10 mL of iodinated contrast media is then injected into the catheter under fluoroscopy, and images of the anterior urethra are taken. Extreme pressure during the injection phase can lead to extravasation and should be avoided. Do not mistake the membranous urethra for a stricture (seen as a "bird's beak" at about the level of the inferior magin of the obturator foramen). See the images below.
Urethral strictures. Retrograde urethrogram demonstrating complete obliteration of the bulbous urethra.
Urethral strictures. Retrograde urethrogram demonstrating patent urethra after buccal mucosa urethroplasty.
Urethral strictures. Retrograde urethrogram demonstrating patent urethra after excision of stricture and primary anastomosis.
An antegrade cystourethrogram involves distending the bladder with water-soluble contrast medium via a suprapubic tube or urethral catheter. A scout film is taken before administration of contrast material. Once the bladder is fully distended with contrast medium, the suprapubic tube is clamped or the urethral catheter is removed and the patient is asked to void. Spot films are taken before, during, and after the voiding phase. This study can help delineate the posterior urethral anatomy.
Ultrasonography of the male urethra can be useful in evaluating urethral strictures. A transducer can be placed longitudinally along the phallus, within the lumen of the urethra or along the perineum. Ultrasonography can be used to evaluate the stricture length and the degree and depth of spongiofibrosis. Several authors have described techniques that involve distension of the urethra with normal saline instilled in a retrograde fashion prior to ultrasonography. Ultrasonography demonstrates thicker periurethral tissues at the level of the stenosis compared with unaffected areas of the urethra.
Ouattara et al showed that urethral strictures identified on perineal sonograms were significantly longer than those identified on retrograde urethrography and voiding cystourethrography. [23] However, in a series of 92 patients, Shahsavari et al found the estimated lengths of strictures were significantly shorter using sonography compared with retrograde urethrography. [8]
A study by Zhang et al evaluated patients with conventional voiding and retrograde urethrography and 64-row multidetector CT (64-MDCT) urethrography and found that 64-MDCT urethrography is a useful alternative to traditional radiographic methods for defining male urethral strictures. [24, 22]
Diagnostic Procedures
Endoscopic evaluation can be conducted by flexible or rigid cystourethroscopy. Flexible cystourethroscopy can be performed with little discomfort to the patient using only local anesthesia, such as 2% lidocaine jelly intraurethrally. Malignancy should be ruled out with an endoscopic biopsy when appropriate. Again, cystoscopy can usually only determine the presence of stricture but cannot accurately delineate the length of the stricture because the proximal extent of stricture cannot be visualized through the small lumen. Because of this, imaging such as retrograde urothrography should be performed before any surgical intervention on urethral stricture.
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Urethral strictures. Cross-sectional diagram of the penis.
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Urethral strictures. Schematic of penile anatomy.
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Retrograde urethrogram demonstrating bulbar urethral stricture.
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Urethral strictures. Retrograde urethrogram demonstrating complete obliteration of the bulbous urethra.
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Retrograde urethrogram demonstrating pan-urethral stricture disease.
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Urethral strictures. Retrograde urethrogram demonstrating patent urethra after buccal mucosa urethroplasty.
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Urethral strictures. Retrograde urethrogram demonstrating patent urethra after excision of stricture and primary anastomosis.
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Urethral strictures. Photograph of a permanent urethral stent.
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Urethral strictures. A buccal mouth graft has been harvested from the inner aspect of the cheek. The graft size is measured to accommodate the length of urethra involved in the onlay.
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Urethral strictures. The buccal mucosal grafts have been secured to the corpora cavernosa. The anastomosis will run along either side of the dorsum of the urethral edges to complete the dorsal onlay. The glans penis (distal) is at the top of the picture. The catheterized urethra with a dorsal urethrotomy is on the left.
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Urethral strictures. Photograph of open urethroplasty depicting the pedicled flap.
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Urethral strictures. Photograph depicting pedicled flap anastomosed to the left side of the urethra. Suturing of the right side of the pedicled flap to the urethra completes the anastomosis.
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Urethral strictures. The anastomosis of the pedicled flap is complete. The pedicle of the flap (left side) originates from the dorsolateral aspect of the penis. The glans penis (distal) is at the top of the photograph.
