URETHRAL STRICTURE DISEASE

Urethral stricture disease
A urethral stricture is an area of narrowing in the calibre of the urethra due to formation of scar tissue in the tissues surrounding the urethra. The disease process of anterior urethral stricture disease is different to that in the posterior urethra.

Anterior urethra
The process of scar formation occurs in the spongy erectile tissue (corpus spongiosum) of the penis that surrounds the urethra spongiofibrosis.
- Inflammation (e.g. balanitis xerotica obliterans BXO), gonococcal infection leading to gonococcal urethritis (less common nowadays because of prompt treatment of gonorrhea)
- Trauma
--  Straddle injuries blow to bulbar urethra (e.g. cross-bar injury)
--  Iatrogenic instrumentation (e.g. traumatic catheterization, traumatic cystoscopy, TURP, bladder neck incision)
The role of non-specific urethritis (e.g. Chlamydia) in the development of anterior urethral strictures has not been established.

Posterior urethra
Fibrosis of the tissues around the urethra results from trauma pelvic fracture or surgical (radical prostatectomy, TURP, urethral instrumentation). These are essentially distraction injuries, where the posterior urethra has been pulled apart, and the subsequent healing process results in the formation of a scar, which contracts and thereby narrows the urethral lumen.

Symptoms and signs of urethral stricture
- Voiding symptoms hesitancy, poor flow, post-micturition dribbling
- Urinary retention acute, or high pressure acute-on-chronic
- Urinary tract infection prostatitis, epididymitis

Management of urethral strictures
Where the patient presents with urinary retention, the diagnosis is usually made following a failed attempt at urethral catheterization. In such cases, avoid the temptation to  blindly  dilate the urethra. Dilatation may be the wrong treatment option for this type of stricture it may convert a short stricture, which could have been cured by urethrotomy or urethroplasty, into a longer and more dense stricture, thus committing the patient to more complex surgery and a higher risk of recurrent stricturing. Place a suprapubic catheter instead, and image the urethra with retrograde and antegrade urethrography to establish the precise position and the length of the stricture.
Similarly, avoid the temptation to inappropriately dilate a urethral stricture diagnosed at flexible cystocopy (urethroscopy). Arrange retrograde urethrography so appropriate treatment can be planned.

Treatment options
Urethral dilatation: designed to stretch the stricture without causing more scarring; bleeding post dilatation indicates tearing of the stricture (i.e. further injury has been caused) and restricturing is likely.

Internal (optical) urethrotomy: stricture incision, with an endoscopic knife or laser. Divides the stricture, followed by epithelialization of the incision. If deep spongiofibrosis is present, the stricture will recur. Best suited for short (<1.5cm) bulbar urethral strictures with minimal spongiofibrosis. Leave a catheter for 3 - 5 days (longer catheterization does not reduce long-term restricturing). Consider ISC for 3 - 6 months, starting several times daily, reducing to once or twice a week towards the end of this period.

Excision and reanastomosis or tissue transfer: excises the area of spongiofibrosis with primary reanastomosis or closure of defect with buccal mucosa or pedicled skin flap; best chance of cure.
A stepwise progression up this  reconstructive ladder  (the process of starting with a simple procedure and moving onto the next level of complexity when this fails) is not appropriate for every patient. For the patient who wants the best chance of long-term cure, offer excision and reanastomosis or tissue transfer up front. For the patient who is happy with lifelong  management  of his stricture (with repeat dilatation or optical urethrotomy), offer dilatation or optical urethrotomy.

Balanitis xerotica obliterans (BXO)
Genital lichen sclerosis and atrophicus in the male. Hyperkeratosis is seen histologically. Appears as a white plaque on the foreskin, glans of the penis, or within the urethral meatus. Most common cause of stenosis of the meatus. Foreskin becomes thickened and adheres to the glans, leading to phimosis (a thickened, non-retractile foreskin). Patients with long-standing BXO and meatal stenosis often have more proximal urethral strictures.