Urethral Stricture
Summary
A urethral stricture is a narrowing of the urethra caused by fibrosis (spongiofibrosis) of the corpus spongiosum and urethral epithelium. It predominantly affects men and presents with obstructive lower urinary tract symptoms (LUTS). The etiology varies by location: anterior strictures are often due to trauma (straddle injury), iatrogenic causes (catheterisation), or infection (gonorrhoea), while posterior strictures are typically associated with pelvic fractures or prostate surgery. Diagnosis is confirmed structurally by Retrograde Urethrography (RGU) and functionally by Uroflowmetry. Management involves endoscopic treatment (dilation/urethrotomy) for simple strictures, but urethroplasty (often with buccal mucosa graft) is the gold standard for recurrent or complex cases. [1,2]
Key Facts
- Incidence: 0.6% of men; increases with age (>65 years).
- Most Common Cause: Iatrogenic (instrumentation/catheterisation) is now the leading cause (~45%). [3]
- Mechanism: Injury → Epithelial Disruption → Urine Extravasation → Spongiofibrosis.
- Diagnostic Gold Standard: Retrograde Urethrogram (RGU).
- Functional Sign: "Box-shaped" or plateau curve on uroflowmetry.
- Treatment Success: Endoscopic (30-50% long-term); Urethroplasty (85-95% long-term).
Clinical Pearls
The "Plateau" Curve: On uroflowmetry, a stricture typically produces a flat, prolonged curve (Qmax reduced, voiding time prolonged), unlike the "bell-shaped" normal curve or the "intermittent" curve of straining.
Lichen Sclerosus (BXO): Balanitis Xerotica Obliterans is a common cause of strictures at the meatus and fossa navicularis. Look for white, atrophic scarring on the glans. These strictures are notoriously recurrent and resistant to dilation.
The "Ladder" of Treatment: Do not repeatedly Dilate/Cut a recurring stricture. Guidelines suggest Dilation/DVIU is firs-line only for short, bulbar strictures. Recurrence should prompt Urethroplasty. "Insanity is dilating the same stricture over and over again."
Catheter Trauma: A major preventable cause. Always ensure the catheter is fully inserted (to the hub) before inflating the balloon to prevent inflating it in the urethra.
Incidence and Demographics
- Prevalence: ~200-600 per 100,000 males.
- Age: Risk increases significantly after age 55.
- Sex: Predominantly male disease. Female strictures are rare (usually distal).
- Economic Burden: Significant healthcare costs due to recurrent procedures.
Aetiology by Location
| Location | Common Causes | Notes |
|---|---|---|
| Posterior (Membranous/Prostatic) | Pelvic fracture (PFUI), TURP, Radical Prostatectomy | Distraction defects rather than true strictures |
| Bulbar Urethra | Idiopathic (40%), Iatrogenic (Catheter/Scope), Straddle Injury | Most common site |
| Penile Urethra | Lichen Sclerosus (BXO), STI (Gonorrhoea), Hypospadias repair | Often longer, complex strictures |
| Fossa Navicularis / Meatus | Lichen Sclerosus (BXO), Instrumentation | Visible externally |
Risk Factors
- Transurethral Surgery: TURP, CABG (catheterisation).
- Traumatic Catheterisation: Forceful insertion.
- STI History: Gonorrhea ("Gonococcal stricture") - historically common, now less so.
- Lichen Sclerosus: Chronic inflammatory condition.
- Hypospadias Repair: Strictures can form decades later.
- Pelvic Radiation: Ischaemic strictures (hard to treat).
Step 1: Epithelial Injury
- Trauma (instrument, bacteria, external force) breaches the urethral epithelium.
- Epithelial integrity is lost.
Step 2: Urine Extravasation
- Urine acts as a chemical irritant.
- Leaks into the underlying Corpus Spongiosum.
- Causes inflammation.
Step 3: Spongiofibrosis
- The hallmark of urethral stricture disease.
- Fibroblasts replace normal vascular spongy tissue with dense collagen scar.
- Use of spongiosum is critical: loss of elasticity.
- Scar contracts, narrowing the lumen.
classification of Spongiofibrosis
- Epithelial: Only lining involved (rare).
- Spongiofibrosis: Scar extends into spongiosum.
- Full thickness: Scar involves entire spongiosum depth.
- Complex: Scar extends outside spongiosum (peri-urethral).
Symptoms (LUTS)
| Symptom | Description |
|---|---|
| Weak Stream | Slow, prolonged voiding |
| Straining | Using abdominal pressure to void |
| Spraying / Splitting | Initial stream splits (common in meatal stricture) |
| Dribbling | Post-void dribbling (urine trapped behind stricture) |
| Frequency/Urgency | Secondary to incomplete emptying or bladder changes |
| Dysuria | Pain on passing urine (often with infection) |
| Haematuria | Occasionally |
Complications at Presentation
Red Flags
- Retention: Immediate drainage needed. Note: Urethral catheter may fail; do not force. SPC is safer.
- Fevers/Rigors: Sepsis (prostatitis/abscess).
- Visible Mass: Penile cancer causing stricture.
- Blood at Meatus: Recent trauma.
Physical Findings
Genitalia
- Meatus: Check for stenosis or BXO (white scarring).
- Palpation: Palpate along corpus spongiosum (ventral penis). Severe fibrosis feels like a hard cord.
- Discharge: Infection.
Abdomen
- Bladder: Palpable if retention.
- SPC scar: Previous drainage.
DRE (Digital Rectal Exam)
- Prostate assessment (BPH can coexist).
- Assess anal tone (neurogenic causes of LUTS).
Functional Tests
1. Uroflowmetry
- Result: Box-shaped / Plateau curve.
- Qmax: Reduced (often less than 10-15 ml/s).
- Volume: Must be >150ml for validity.
2. Post-Void Residual (PVR)
- Ultrasound bladder scan.
- Elevated in significant obstruction.
Imaging (Structural) - Essential
Retrograde Urethrogram (RGU)
- Gold Standard.
- Contrast injected via meatus.
- Defines: Location, Length, Number, and Density of stricture.
Micturating Cystourethrogram (MCUG)
- Voiding phase.
- Visualizes proximal urethra (dilated behind stricture).
- Assessing posterior urethra/bladder neck.
Endoscopy
Flexible Cystoscopy
- Direct visualisation.
- Assess calibratibility (passable or typically not).
- Evaluate bladder for secondary changes (trabeculation) or stones.
Lab Tests
- Urinalysis/Culture: Rule out infection.
- Creatinine: Renal function check.
- STI Screen: If young/risk factors.
Management Algorithm
DIAGNOSED STRICTURE (RGU)
↓
┌─────────────────────────────────────────────┐
│ ASSESS STRICTURE │
│ - Length (less than 2cm vs >2cm) │
│ - Location (Bulbar vs Penile) │
│ - Recurrence (First time vs Recurrent) │
└─────────────────────────────────────────────┘
↓
┌───────────┴───────────┐
↓ ↓
SHORT (less than 2cm) & LONG (>2cm) or
BULBAR & FIRST TIME PENILE or RECURRENT
↓ ↓
ENDOSCOPIC MANAGEMENT URETHROPLASTY
(Dilation / DVIU) (Reconstruction)
↓ ↓
┌───────┴───────┐ ┌─────┴─────┐
↓ ↓ ↓ ↓
SUCCESS FAILURE ANASTOMOTIC SUBSTITUTION
(Observation) ↓ (End-to-end) (Graft/Flap)
RECURRENCE
↓
DO NOT REPEAT DVIU
Refer for Urethroplasty
Endoscopic Management
First-line only for: Short (less than 2cm), Bulbar, Primary strictures.
-
Urethral Dilation:
- Sequential widening with sounds/balloons.
- Creates mucosal tears that heal (hopefully open).
- High recurrence rate.
- Self-Catheterisation (ISC) often needed to maintain patency.
-
DVIU (Direct Visual Internal Urethrotomy):
- Cold knife or Laser incision of the scar (12 o'clock position).
- Success: ~50-60% for ideal candidates.
- Risk: Extravasation, bleeding, recurrence.
Surgical Reconstruction (Urethroplasty)
Gold standard for: Recurrent, Long, or Penile strictures.
-
Excision and Primary Anastomosis (EPA):
- Cut out the scar, sew ends together.
- Best for: Short bulbar strictures (less than 1-2cm).
- Success: >90-95%.
-
Substitution Urethroplasty:
- For longer strictures where ends can't meet.
- Buccal Mucosa Graft (BMG): Gold standard graft material (from inner cheek). Robust, resistant to infection, wet environment.
- Penile Skin Flap: Second line.
- Success: 85-90%.
Posterior Strictures (PFUI)
- Pelvic Fracture Urethral Injury.
- Often complete disruption.
- Requires "Bulbo-Prostatic Anastomosis" (delayed repair 3-6 months after injury).
Follow-Up
- RGU or Cystoscopy at 3-12 months.
- Monitor flow rates.
Disease-Related
- Retention: Acute or Chronic.
- Renal Failure: From high-pressure retention.
- Infection: UTI, Prostatitis, Abscess, Fournier's Gangrene.
- Bladder Decompensation: Hypocontractile bladder from chronic obstruction.
- Stones: Bladder calculi.
Treatment-Related
- Recurrence: Main complication.
- Incontinence: Risk if sphincter damaged (especially posterior repairs).
- Erectile Dysfunction: Risk in dissection near neurovascular bundles.
- Ejaculatory Dysfunction: Pooling of semen, reduced force.
- Cordee/Penile Shortening.
Success Rates
- DVIU/Dilation:
- First attempt: 50% recurrence free at 5 years.
- Second attempt: less than 30% success.
- Third attempt: 0% long-term success. Do not perform >2 DVIUs.
- Urethroplasty:
- EPA: >90-95% durable success.
- BMG: 85-90% durable success.
Impact on Life
- Significant QoL improvement after successful surgery.
- Recurrent strictures cause depression, anxiety, and repeated procedures.
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| Urethral Strictures | SIU / ICUD | Endoscopy only for simple bulbar; Urethroplasty for restenosis |
| Reconstructive Urology | EAU | Avoid repeated urethrotomies. Use BMG for substitution. |
| Stricture Guideline | AUA | Imaging (RGU) mandatory before treatment. |
Landmark Studies
1. Heyns et al. (2010)
- Question: Dilation vs DVIU?
- Result: No difference in efficacy. Both have high recurrence.
- Impact: Choice depends on surgeon preference/cost.
2. Santucci et al. (2010)
- Question: Cost effectiveness?
- Result: Immediate urethroplasty is more cost-effective than repeated DVIUs due to low success of DVIU.
- Impact: Push for earlier urethroplasty.
3. Barbagli et al. (Many)
- Contribution: Popularised Dorsal Onlay BMG.
- Impact: Standardised the technique for bulbar urethroplasty.
What is a Urethral Stricture?
It is a scar tissue narrowing of the urethra (the water pipe that carries urine out of the penis). Think of it like a kink or blockage in a hose.
What Causes It?
- Injury: Straddle injuries (falling on a bike bar/fence) or pelvic fractures.
- Medical Procedures: Previous catheters or prostate surgery can leave scars.
- Infection: Previously gonorrhoea, now rare.
- Skin conditions: Lichen sclerosus (a white scarring skin disease).
What are the Symptoms?
- Very slow flow of urine.
- Spraying or splitting of the stream.
- Having to push/strain to pee.
- Dribbling after you finish.
- Frequent urinary infections.
How is it Diagnosed?
- Flow Test: You pee into a machine that measures speed.
- Dye Test (X-ray): Dye is gently put into the urethra to take an X-ray picture of the narrowing.
- Camera Test: Looking inside with a small scope.
How is it Treated?
- Stretching/Cutting (Endoscopy): For simple, first-time strictures, doctors can stretch it or make a small cut internally. It is simple but the stricture often comes back.
- Reconstruction (Urethroplasty): Major surgery where the scar is removed or widened using a patch of skin (usually from the inside of your cheek). This has a very high success rate and is the best option for strictures that keep coming back.
What happens if ignored?
It can lead to complete blockage (unable to pee), severe infections, or bladder/kidney damage.
Primary Sources
- Morey AF, et al. SIU/ICUD Consultation on Urethral Strictures: Anterior Urethra. Urology. 2014;83:S1-S16.
- Lumen N, et al. EAU Guidelines on Urethral Strictures. European Association of Urology. 2021.
- Mundy AR, Andrich DE. Urethral strictures. BJU Int. 2011;107:6-26. PMID: 21176068.
- Santucci RA, et al. Male Urethral Stricture Disease. J Urol. 2007;177:1667-1674.
- Barbagli G, et al. Bulbar urethroplasty using buccal mucosa grafts placed on the ventral, dorsal or lateral surface of the urethra: are results affected by the surgical technique? J Urol. 2005;174:955-958.
Common Exam Questions
- MRCS/FRCS (Urol): "A 30-year-old male has a recurrence of a bulbar stricture 6 months after DVIU. What is the management?"
- Answer: Urethroplasty (Excision & Primary Anastomosis if short, or BMG if longer). NOT repeat DVIU.
- Clinical: "Describe the uroflowmetry trace of a stricture."
- Answer: Plateau curve (Box shape). Prolonged voiding time. Low Qmax.
- Anatomy: "Where is the most common site for simple iatrogenic strictures?"
- Answer: Bulbar urethra.
- Pathology: "What is the hallmark histological feature?"
- Answer: Spongiofibrosis.
Viva Points
- Catheters: Only inflate balloon if urine flows or catheter is to the hilt. Avoid traumatic catheterisation.
- BXO: Always examine the meatus. BXO strictures need careful management (often resistant to graft).
- Grafts vs Flaps: BMG is standard. Flaps (skin) used only if BMG not available or complex, but hair-bearing skin is bad (stones).
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