Urethral stricture refers to a condition where urethral luminal narrowing caused by organic lesions leads to increased urinary flow resistance and consequent difficulty in urination.
Etiology and Classification
The causes include trauma, inflammation, iatrogenic factors, and congenital abnormalities. Urethral strictures can be classified based on their location into anterior and posterior urethral strictures. The most common sites of urethral stricture in males are the membranous urethra, penile urethra, and bulbar urethra, in that order. The most frequent cause of bulbar urethral stricture is straddle injury, while membranous urethral strictures are commonly associated with urethral injuries resulting from pelvic fractures. Iatrogenic causes include prolonged catheterization, endoscopic procedures, or surgical operations.
Clinical Manifestations
The primary manifestations involve voiding-phase symptoms, with difficulties in urination being most prominent. These include a thin or dribbling urinary stream, reduced urinary stream projection, prolonged urination time, among others, which vary depending on the site, length, and severity of the stricture. Strictures near the urethral meatus may present with a thin yet lengthy urine stream. Longstanding cases can lead to complications such as detrusor muscle decompensation, chronic urinary retention, urinary tract infections, bladder diverticula or calculi, overflow urinary incontinence, bilateral upper urinary tract dilation, and chronic renal insufficiency.
Diagnosis
Evaluation typically includes a thorough inquiry into the patient’s history of trauma, infection, iatrogenic procedures, surgeries, the onset of the stricture, and details of prior treatments. The stricture's location, length, and severity, as well as the presence of complications, should be clarified. In anterior urethral strictures in males, palpation may reveal hardened or cord-like tissue at the site of the stricture. Tenderness and urethral discharge should also be noted.
Laboratory investigations typically include urinalysis, urine culture with sensitivity testing, and renal function assessment. Uroflowmetry aids in evaluating the degree of urethral narrowing and its impact on voiding. Urethral sound probing is useful for diagnostic purposes. Urethrography, including retrograde urethrography and voiding urethrography, provides a clear depiction of the location, length, and severity of the stricture and is considered a first-line diagnostic method. Sagittal MRI imaging may provide better visualization of posterior urethral injuries and prostate displacement. Urethrocystoscopy allows direct observation of urethral lumen narrowing, scar tissue, and urethral mucosal conditions.
Treatment
Urethral Dilatation and Internal Urethrotomy
For short-segment urethral strictures, treatment options include urethral dilatation or scar incision using a cold knife or laser under urethroscopic guidance. Short, soft scar segments may be managed with periodic urethral dilatation.
E### xcision of Urethral Scar Tissue and End-to-End Anastomosis
This is the most common approach for treating traumatic urethral strictures. It is suitable for membranous urethral strictures and bulbar urethral strictures of ≤3 cm in length. The surgical procedure involves complete excision of the scar tissue surrounding the urethra and the narrowed urethral segment, followed by tension-free end-to-end anastomosis of the urethral ends.
Other Treatments
Meatal Urethral Stricture
Meatal incision surgery is simple and yields reliable results.
Complex Urethral Stricture
For more difficult cases, particularly those involving long-segment strictures, open urethroplasty can be performed.
Penile Urethral Stricture
Techniques such as penile skin flap urethroplasty and free mucosal graft urethroplasty may be used.
Urethral Stent Placement
Urethral stents have shown efficacy in managing urethral strictures to some degree.