Anterior Urethral Stricture

Anterior urethral stricture is a narrowing with spongiofibrosis of the urethra distal to the perineal membrane, involving the bulbar urethra, penile urethra, fossa navicularis or meatus. The bulbar urethra is the most common site.

Causes include idiopathic (the largest group), iatrogenic injury from catheterisation or instrumentation, straddle trauma, inflammatory disease including lichen sclerosus, infection (gonococcal historically) and failed hypospadias repair.

Pathophysiology. Injury to the urethral epithelium allows urine extravasation into the corpus spongiosum, causing inflammation and fibrosis that narrows the lumen.

Fibrosis often extends beyond the visible mucosal narrowing, and the length of spongiofibrosis largely determines treatment success.

Weak or spraying stream, straining, hesitancy, incomplete emptying, post-void dribble, recurrent urinary tract infection, haematuria and acute retention. Complications include epididymo orchitis, prostatitis, periurethral abscess, urethral fistula, diverticulum, stones, bladder trabeculation and renal impairment.

Examine the meatus and penile skin for lichen sclerosus, palpate the urethra for induration, and check for a palpable bladder.

• Uroflowmetry: peak flow under 10 mL/s with a flat plateau curve is typical.
• Post-void residual, urine culture, creatinine and renal ultrasound.
• Combined retrograde urethrography and voiding cystourethrography, with oblique views, defines site, length and degree. When the bladder is catheterised suprapubically, add antegrade imaging.
• Flexible cystoscopy: inability to pass a 16 Fr scope confirms a clinically relevant stricture.
• Urethral ultrasound estimates the depth of spongiofibrosis.
• Biopsy of suspicious meatal or glans skin for lichen sclerosus.

Differential diagnosis.

• Benign prostatic enlargement
• Bladder neck contracture or obstruction
• Detrusor underactivity
• Meatal stenosis
• Urethral cancer
• Urethral stone
• Urethral diverticulum
• Neurogenic bladder
• Prostatitis

• Retention: suprapubic catheter is preferred. Urethral catheterisation is attempted only gently with a small catheter by an experienced operator, since forced passage creates false passages.
• Dilation or direct vision internal urethrotomy is reasonable once for a short (under 2 cm), first time bulbar stricture. Long term success is about 50% at best and falls sharply with each repeat. After incision, a catheter is left for 2 to 5 days, and an antibiotic is given in a single dose directed by the latest culture.
• Intermittent self-dilatation with a 12 to 14 Fr catheter after urethrotomy lowers recurrence while in use. The frequency used varies and is usually tapered over months.
• Urethroplasty is the definitive treatment for recurrence after one endoscopic procedure, for strictures over 2 cm and for penile strictures. Success is about 85 to 95%.
  • Excision and primary anastomosis for short bulbar strictures.
  • Buccal mucosa graft (dorsal or ventral onlay) for longer strictures.
  • Staged repair for lichen sclerosus or failed graft.
• Lichen sclerosus: clobetasol propionate 0.05% ointment, thin layer once daily at night for 4 weeks, then reduced as the skin allows, with review at 3 months. Use buccal mucosa rather than penile skin for grafts.
• Permanent urethral stents are largely abandoned because of tissue ingrowth.

Monitoring. Uroflowmetry at 3, 6 and 12 months after treatment, then yearly. Peak flow over 15 mL/s with symptom relief is success. Flexible cystoscopy if symptoms recur.

Referral and escalation. Refer to urology, and to a reconstructive urologist for urethroplasty. Urgent referral for retention, renal impairment, abscess or fistula.