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STRICTURES


STRICTURES
Strictures of the male urethra may involve any segment, including the meatus, penile, bulbar, membranous, and prostatic urethra. The urethral narrowing may be mild, such that a stent or small cystoscope may pass, or severe, such that even a guidewire cannot be passed. Stricture length also varies from a short, simple narrowing to a long, complex stricture. Strictures may be single or multiple.

STRICTURES

Strictures may develop following bacterial, viral, or sexually transmitted (Chlamydia and gonorrhea) infections or as a complication of indwelling catheters. Infections tend to lead to long, inflammatory strictures, with 50% occurring in the bulbar urethra, 30% in the penile urethra, and the rest elsewhere. Straddle injuries, penile trauma, punctures, and tears from improper use of sounds, catheters, stylets, and cystoscopes may also lead to severe, short strictures, generally in the bulbar urethra, with significant periurethral scar tissue that responds poorly to repeated dilation.
The degree and duration of urethral inflammation and individual propensity to form scar tissue all affect stricture onset and severity. Urethral strictures consist of poorly vascularized scar tissue that often responds to the trauma of repeated dilation with further inflammation and scar tissue. Scar tissue within the penile urethra usually occurs on the floor, whereas in the bulbar urethra, scar tissue is often located on the roof and may be palpable as an indurated mass that may invade the corpus spongiosum. Periurethral scar tissue can be extensive and of such long duration that the underlying urethral mucosa is completely denuded and appears stark white cystoscopically. The urethra proximal to a stricture may become dilated as a consequence of obstruction to urinary flow, resulting in bilateral hydronephrosis and renal insufficiency.
The most common symptoms are small caliber and weak or split urinary stream, urinary frequency, dysuria, and occasionally gross hematuria, pyuria, and urinary tract infection. Severe strictures may also lead to post-void dribbling of urine. Acute urinary retention may also occur. Strictures are often complicated by infections that include prostatitis, epididymitis, cystitis, and, occasionally, pyelonephritis. Urethral abscess may develop with spontaneous extravasation of urine proximal to the blocked area, resulting in one or more urethrocutaneous fistulae often referred to as “watering pot perineum.” Fistulae may heal spontaneously but then recanalize when abscesses recur. Granulation tissue usually lines the fistulous tracts. Extensive fistulae may open into the buttock and groin as well as the perineum. With chronic extravasation, virulent bacteria may lead to extensive penile, scrotal, and perineal cellulitis as well as gangrenous fasciitis (Fournier gangrene) (see Plate 2-20).
Urethral strictures are diagnosed in several ways. Often it is not possible to pass a urethral catheter. Or, the catheter may pass entirely, but as it enters the strictured area, it is held tightly and needs more force to pass. A nontraumatic retrograde urethrogram with a plain film of the tilted pelvis can assess the severity and length of the strictured urethral lumen. High-frequency penile or perineal ultrasound is particularly good at assessing the extent of damage to associated corpus spongiosal tissue for surgical planning. Repeat dilation is usually only palliative treatment, as this may worsen scar tissue. For fine strictures of the bladder neck after radical prostatectomy, balloon dilation may often be sufficient. For other simple strictures, cystoscopy and optical urethrotomy is effective in 80% of cases. If strictures recur after endoscopic treatment, formal urethroplasty in which all scarred tissue is excised and healthy urethra reanastomosed is often performed. The excision of long strictures may not allow end-to-end reconnection of the urethral tissue; in such cases, onlay or replacement tubular grafts with penile or preputial skin or bladder or buccal mucosa are routinely used with excellent and durable success.