Bulbar Urethral Stricture

Bulbar urethral stricture is narrowing of the urethra between the perineal membrane and the penoscrotal junction, surrounded by the corpus spongiosum. It is the most common anterior stricture.

Causes are idiopathic in most patients, then straddle injury, iatrogenic injury after catheterisation or transurethral surgery, and infection. The thick spongiosum makes the bulbar segment well suited to anastomotic repair in short strictures and graft repair in long ones.

Pathophysiology. Perineal trauma compresses the bulbar urethra against the pubic symphysis, or instrumentation injures the mucosa.

Urine leaks into the spongiosum, causing fibrosis that extends longitudinally beyond the visible lumen narrowing.

Slow spraying stream, straining, post-void dribble, incomplete emptying, perineal discomfort, recurrent urinary infection, haematuria, acute retention and epididymitis. A history of straddle injury, previous catheterisation or earlier urethrotomy is common. Examination may reveal a thick palpable perineal urethra and a distended bladder.

• Uroflowmetry with a plateau curve and peak flow under 10 mL/s, plus residual urine volume.
• Retrograde urethrography with voiding cystourethrography, with oblique views. Measure stricture length, number of segments, and distance from the membranous urethra, since the proximal end determines whether the sphincter region is involved.
• Urethral ultrasound for spongiofibrosis depth. Flexible cystoscopy if imaging is equivocal.
• Creatinine, urine culture, renal ultrasound.

Differential diagnosis.

• Bladder neck or prostatic obstruction
• Posterior urethral stricture
• Detrusor underactivity
• Urethral diverticulum
• Stone
• Urethral cancer
• Prostatitis

• Retention: suprapubic catheter.
• First time stricture under 2 cm and non-dense: one dilation or internal urethrotomy, catheter 2 to 5 days. A second endoscopic procedure is of low yield and delays definitive repair.
• Excision and primary anastomosis: for strictures about 2 to 2.5 cm or less, success 90 to 95%. Limit extent so there is no chordee from tension.
• Buccal mucosa graft urethroplasty (dorsal or ventral onlay): strictures over 2 to 2.5 cm, success 80 to 90%.
• Long or panurethral disease: graft, flap or staged repair in specialist units.
• A paclitaxel coated balloon dilation is newly available for short strictures (under about 3 cm) and its long term data are limited.
• Postoperative: catheter 2 to 3 weeks, a pericatheter urethrogram before removal to confirm healing. Complications include transient erectile dysfunction, reduced ejaculatory force, penile shortening or chordee after long anastomosis, wound infection, and recurrence.

Monitoring. Uroflowmetry at 3, 6 and 12 months, then yearly for several years, with flexible cystoscopy or urethrography for symptoms or falling flow.

Referral and escalation. Refer to a reconstructive urologist after the first recurrence. Urgent referral for retention, abscess, fistula or renal impairment.