Urethral Stricture

Definition

Aetiology

Large catheters and instruments cause ischemia and internal trauma - the ischemic mechanism is key to catheter-related strictures. - Smith and Tanagho's General Urology, 19th Edition

Pathophysiology

• Fibrotic narrowing restricts urine flow
• Proximal urethra and prostatic ducts become dilated
• Prostatitis is a common downstream complication
• Bladder muscle undergoes hypertrophy; residual urine increases
• Severe prolonged obstruction: decompensation of ureterovesical junction → vesicoureteric reflux → hydronephrosis → renal failure
• Urethral fistulas and periurethral abscesses develop with chronic severe strictures

Anatomy of Affected Sites

• Bulbar urethra - most common site (trauma, especially straddle injuries)
• Membranous urethra - pelvic fracture injuries
• Penile/anterior urethra - instrumentation, hypospadias repair
• Fossa navicularis - meatal/distal strictures

Clinical Features

• Decreased urinary stream (most common complaint)
• Spraying or double stream
• Postvoid dribbling
• Chronic urethral discharge (often with concurrent prostatitis)
• Urinary frequency, mild dysuria
• Acute urinary retention (less common unless superimposed infection or prostatic obstruction)

• Palpable induration at stricture site
• Tender periurethral masses (periurethral abscess)
• Urethrocutaneous fistulas
• Palpable bladder (chronic retention)

Investigations

Urinary Flow Rate

• Normal: ~20 mL/s
• Significant stricture: <10 mL/s
• The patient collects 8-10 timed 5-second midstream samples; mean peak flow is calculated

Imaging

• Retrograde urethrogram (RUG) + voiding cystourethrogram (VCUG) - gold standard; demonstrates location, length, and extent of stricture
• Sonourethrography - useful adjunct for assessing degree of spongiofibrosis
• Excretory urography if upper tract involvement suspected

Endoscopy

• Urethroscopy: direct visualization; characterizes stricture length, caliber, location
• Bougies à boule: calibrate the stricture
• Small-caliber strictures prevent instrument passage

Complications

1. Urinary retention (acute or chronic)
2. Chronic prostatitis and cystitis
3. Periurethral abscesses
4. Urethrocutaneous fistulas
5. Urethral diverticula
6. Vesical calculi (from stasis and infection)
7. Vesicoureteric reflux
8. Hydronephrosis / renal failure
9. Urethral carcinoma (long-standing strictures)

Differential Diagnosis

• Benign prostatic hyperplasia / prostatic carcinoma
• Bladder neck contracture (post-TURP)
• Urethral carcinoma (irregular lesion on urethroscopy; confirmed by biopsy)

Treatment

1. Urethral Dilation

• Seldom curative - fractures scar tissue temporarily; re-fibroses during healing
• Techniques: filiform and followers, Van Buren urethral sounds, balloon dilation
• Used for symptom relief or acute/chronic retention
• Generous lubrication is essential; small sounds risk false passage creation

2. Direct Vision Internal Urethrotomy (DVIU)

• A sharp knife attached to an endoscope incises the stricture under direct vision
• A guidewire is passed first; multiple circumferential incisions made; catheter left briefly
• Short-term success: 70-80% of patients
• Long-term success rates are much lower - recurrence is common
• Advantages: minimal anesthesia (topical + sedation), easily repeated, very safe
• More precise than dilation with less injury to surrounding healthy urethra
• Important: DVIU has a much lower long-term success rate than historically reported; repeated DVIU worsens scarring by generating more inflammation

3. Open Surgical Reconstruction (Urethroplasty)

• Short strictures (≤2 cm) of bulbar urethra: complete excision + end-to-end anastomotic urethroplasty (best long-term results)
• Longer or penile strictures: tissue substitution required:
  • Buccal mucosa graft (most commonly used graft material today)
  • Penile fasciocutaneous flaps (e.g., circular fasciocutaneous flap)
  • May be staged (especially in complex/recurrent cases)
• Perineal urethrostomy: permanent diversion option for complex cases

4. Prevention (Iatrogenic)

• Use of Otis urethrotomy prior to TURP reduces postoperative stricture incidence
• Use appropriately sized catheters; minimize catheter dwell time

Recent Evidence (2025)

Summary Algorithm

Urethral Stricture Diagnosed
        |
        ├── Short, first-occurrence, symptomatic
        |       └── DVIU (or dilation)
        |               └── Recurs → Open Urethroplasty
        |
        ├── Short bulbar (≤2 cm)
        |       └── Excision + End-to-end anastomosis
        |
        └── Long / complex / penile
                └── Buccal mucosa graft / Flap urethroplasty
                        (± staged repair)