Urethral Stenosis (Stricture)

Understanding the urethra and urethral stenosis

The urethra is the tube through which urine exits the bladder. In men it passes through the penis — sperm also exits via the urethra. In women the urethra is much shorter and its outer orifice is located just above the vagina.

Stenosis (stricture) occurs when part of the urethra becomes narrower. It can involve any part of the urethra and there is usually scar tissue around the narrowed segment. The length of a narrowing can vary from 1 cm to 4 cm or more. Urethral stenosis is rare in women.

What causes urethral stenosis?

Injury or Trauma

When the urethra is injured or damaged, scar tissue develops during healing that causes the stenosis. The most common injuries include:

• • Fractures of the pelvis — for example after a car accident
• • A "straddle" fall (e.g. falling onto a bicycle frame)
• • Medical procedures such as urethral catheterisation, prostatectomy, or radiotherapy for genitourinary malignancies

Infection (Urethritis)

Infection of the urethra can cause inflammation in the tissues in and around the urethra. Even though infections are usually treated with antibiotics, they can leave scar tissue behind, causing stenosis. Common infectious causes include:

• • Sexually transmitted diseases such as gonorrhoea or chlamydia
• • Infection resulting from prolonged urinary catheter use

Note: most urethral infections do not cause stricture — it is a possible complication, not a certainty.

Other Causes

• • Congenital: some babies are born with urethral strictures
• • Cancer: malignancy transmitted from the prostate or bladder is a rare cause

What are the symptoms of urethral stricture?

• • Decreased urine flow — usually the first symptom
• • Difficulty urinating and straining to get urine out of the bladder
• • Urination as a "spray" or forked stream
• • Post-void dribbling — drops of urine continuing after finishing urination
• • Frequent urination (less common)
• • Tingling in the urethra or slight pain when urinating

What are the possible complications?

The narrowing acts like the neck of a bottle — the bladder needs more pressure and force to push urine through. Often not all urine exits and residual urine remains in the bladder. This residual urine can be colonised by bacteria, making infections of the bladder, prostate and kidneys more likely.

Urethral cancer is a rare but possible consequence of a long-term urethral stricture.

What tests are needed?

Uroflowmetry

A test that measures urine flow — how much urine passes per second. When there is a narrowing this amount is reduced. It is carried out by urinating into a special machine.

Urethrо-cystography

A special X-ray examination that will show the location and length of the stenosis.

Urethroscopy

Direct endoscopy with a video camera (cystoscope) to assess the narrowing visually.

Treatment of urethral strictures

Treatment options include endoscopic urethrotomy, urethral dilations, permanent urethral stents, and open surgical urethroplasty.

Endoscopic Urethrotomy

Performed with a cystoscope, a special knife is inserted and the scar is cut endoscopically to increase the diameter of the narrowed urethra. It is usually applied when the length of the narrowing does not exceed 2 cm. The main disadvantage is a high relapse rate — the stenosis returns in about 7 out of 10 patients in the long term, and often worsens.

Urethral Dilations

Special catheters are inserted into the urethra to open the narrowing. This procedure must be repeated at regular intervals, often weekly, and is not a permanent solution.

Permanent Urethral Stents

A stent is a tubular metal mesh that serves as a scaffold to keep the urethral lumen open after dilation or urethrotomy. However, placement of the mesh can aggravate the stenosis — scar tissue can develop along its entire length, turning a short narrowing into a severe stenosis that is difficult to restore surgically. Hypertrophic tissue can also grow through the mesh and re-close the urethra, or the stent can migrate into the bladder.

Stents are generally preferred only in elderly patients with severe cardiovascular problems who cannot receive any form of anaesthesia other than local.

Surgical Treatment — Anastomotic Urethroplasty

The only treatment that can yield a definitive cure is anastomotic urethroplasty, with success rates that can reach 100% in appropriate cases.

• • Short strictures (≤ 2 cm): the narrowed portion of the urethra is excised along with the scar tissue and the two ends are anastomosed (joined and sutured together).
• • Longer strictures: reconstruction of the urethra is necessary, using tissue such as penile skin with its blood vessels, or a mucosal graft from the inside of the cheek (buccal mucosa) or skin from behind the ear.
• • The same technique can be applied to congenital abnormalities of the urethra such as hypospadias or epispadias.