The urethra is a tubular structure that brings urine from the bladder to the outside. Urethral stricture is a condition in which the caliber of the lumen of the urethra diminishes and may even be completely occluded. The female urethra is only 4 cm long and is not generally prone to stricture formation. The male urethra (about 20 cm long) is subdivided into 4 parts: from the tip to the penoscrotal junction, pendular urethra; from the penoscrotal junction to the external urethral sphincter, bulbar urethra; through the external sphincter, membranous urethra and through the prostate up to the bladder neck, prostatic urethra. The first 2 parts constitute the anterior urethra, while the latter 2 constitute the posterior urethra.
Causes of anterior urethral stricture:
1) Balanitis Xerotica Obliterans (BXO) 2) Gonococcal or Nongonococcal Urethritis 3) External Trauma: Gunshot, stab injury, fall-astride injury 4) Internal trauma: Instrumentation, catheter
Causes of Posterior urethral stricture:
1) External Trauma: Road Traffic Accident with Pelvic fracture 2) Internal trauma: Instrumentation such as in TURP
Signs And Symptoms:
Patients present with a decrease in force and caliber of the stream. There may be a history of urethritis, trauma, catheterization or instrumentation. Examination may reveal evidence of BXO, external scars and fistulae, pelvic or lower limb deformity, and presence of a suprapubic tube in cases of complete obliteration of the urethra.
Investigations in a case of urethral stricture:
1) X-ray KUB 2) Retrograde urethrogram (RGU) 3) Micturating cystourethrogram (MCU) 4) Ultrasound - upper tracts 5) Endoscopy, antegrade and retrograde 6) IVU - optional 7) MRI – optional
Wait and Watch
Dilatation: is usually performed for mild passable strictures and can be used for primary treatment or follow-up treatment of SU treated with other methods. Dilation can be achieved with metallic sounds/bougies or filiform dilators with followers or with an endoscope
Internal Urethrotomy (IU): Involves an endoscopic cold-knife cut with an instrument called a urethrotome. It works best for passable short segment (2cm) strictures. Patients usually require a catheter for a few days post-operatively and the long-term success rate is 50-70%. If 3 failures of IU occur in 12 months another method of treatment is indicated.
Core through Urethrotomy: is carried out for complete obliterations of posterior urethra that are short segment strictures (<2cm) using either cold knife or diathermy or laser. There is a risk of false passage or rectal injury
Anastomotic procedures: These are done most often for obliterative posterior strictures, by an open operation under GA through a perineal or transpubic approach. This method can bridge upto 5 cm defects in the posterior and 1 cm defects in the anterior urethra with a 90% long term success.
Substitution procedures (grafts/flaps): These procedures can be done in 1-stage or 2-stage and are required when the defect is too long and too severe to be suitable for regenerative or anastomotic procedures. The principle is to bring extraneous tissue for construction of the neourethra from the prepuce, perineoscrotal skin, free grafts of skin, buccal or bladder mucosa
Urethral stents: Is the operation of last resort since the cost is high and complications frequent