Urethral Stricture - Causes

Causes

Urethral strictures are generally caused by either injury-related trauma to the tract or by a viral or bacterial infection of the tract, often caused by certain sexually transmitted infections (STIs). The body's attempt to repair the damage caused by the injury or infection creates a buildup of scar tissue in the tract resulting in a significant narrowing or even closure of the passage.

Instrumentation of the urethra, particularly before the advent of flexible uro-endoscopy, was—and remains—an important causative event.

Short strictures in the bulbar urethra, particularly between the proximal 1/3 and distal 2/3 of the bulb, may be congenital. They probably form as a membrane at the junction between the posterior and anterior urethral segments. It is not usually noticeable until later in life, as it fails to widen as the urethra does with growth, thus it only impedes urinary flow relative to the rest of the urethra after puberty. Moreover, the patient will often not "know any different", and so will not complain about poor flow.

The urethra runs between the legs very close to the skin, leaving it vulnerable to trauma. Simply falling off a bike and hitting between the legs may result in the formation of scar tissue within the urethra tract. This condition is often not found until the patient has problems urinating because these are painless growths of scar tissue.

Passage of kidney stones through the urethra can be painful and subsequently can lead to urethral strictures.

In infants and toddlers, urethral strictures can result from inflammation following a circumcision and may not noticeable until toilet training when a deflected stream is observed or when the child must strain to produce a urinary stream.