Introduction

Urethral strictures are narrowing in a segment or segments of the urethra as it runs its course from the bladder to the urethral meatus. They are more common in men and rare in women.

Strictures may be idiopathic but are usually the result of previous scarring or trauma to the urethra (e.g. from infections or medical procedures). Patients will typically present with voiding symptoms (e.g. weak flow, straining and dribbling) and those who are not fully emptying their bladder as a result of the stricture may also have storage symptoms (e.g. frequency and urgency).

Epidemiology

  • Incidence: 50.00 cases per 100,000 person-years
  • Peak incidence: 70+ years
Condition Relative
incidence
Benign prostatic hyperplasia100.00
Urethral stricture1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Aetiology

Urethral strictures used to be more commonly caused by untreated sexually transmitted infections but with health education this is now much less common a cause than it used to be.
  • Iatrogenic (45%) - transurethral interventions, traumatic catheter insertions, correction of hypospadias, prostatectomy and radiotherapy can all cause urethral strictures.
  • Idiopathic (30%) - sometimes this may be due to a forgotten minor trauma to the perineum (e.g. when riding a bicycle).
  • Infection (20%) - gonorrhoea and Chlamydia are the usual causative organisms and can cause multi-segment disease.
  • Other causes:
    • Lichen sclerosis - can be a cause in women or men (as balanitis xerotica obliterans).
    • Pelvic trauma - includes crush injuries as well as minor perineal traumas.
    • Congenital urethral stricture
    • Cancers - primary and secondary neoplasia affecting the penis and prostate.

Clinical features

History:
  • Voiding symptoms are the commonest presentation (70%). If you imagine the urethra is a hose and the stricture is a kink in the hose, you can imagine the symptoms.
    • Weak flow of urine (also includes reduced force of ejaculation)
    • Straining to pass urine
    • Terminal dribbling
    • A double stream or spraying of urine (particularly if the stricture is more distal).
  • Storage symptoms may occur due to incomplete emptying of the bladder including
    • Frequency
    • Occasionally dysuria
    • Recurrent urine infections

Examination:
  • In men - examination of the penis is usually normal but there may be some palpable thickening if strictures affect the penile urethra. There can also be signs of causative pathologies e.g. scarring from surgical procedures, hypospadias or signs of balanitis xerotica obliterans.
  • In both sexes - examination of the abdomen may reveal a palpable or percussible bladder if enlarged as a result of urinary retention. Meatal strictures may be visible.

Investigations

Investigations that should prompt consideration of a urethral stricture includes post-void residual urine in the bladder on an ultrasound scan. Also if patients have had positive swabs for Chlamydia or Gonorrhoea as these can cause urethral strictures in both sexes.

Diagnostic investigations are usually arranged by secondary care and include:
  • Urine flowmetry - typically shows a pattern of prolonged urination time with low level peaks and plateaus in maximum flow rate. This is non-invasive but gives little information about where the stricture is and the length of it.
  • Imaging:
    • Ultrasound of the urethra - least invasive option. Often useful for surgical planning as the length and degree of scarring around the stricture.
    • Urethrogram - a fine catheter is inserted into the urethra and a radio-opaque dye is injected to show the stricture.
    • MRI scan - rarely used.
  • Urethroscopy - useful for diagnosing a stricture but if the camera cannot be passed beyond the stricture then other ways must be considered to gain information about the length of the lesion and degree of scarring.

Differential diagnosis

In men:
  • Prostatic enlargement (due to benign hyperplasia, prostatitis or cancer) is the main differential and should be considered particularly in men above 50 years.
    • Similarities: due to the mechanical nature of the obstruction the pattern of symptoms is often the same.
    • Differences: presence of additional red flag symptoms (e.g. haematuria, weight loss, back pain, erectile dysfunction), absence of a causative factor for a stricture in the history, urethral strictures usually present in the 20-40 age group and prostatic disease is more common above 50 years of age, gradual and progressive symptoms more likely with prostatic enlargement.
  • Penile cancer although rare may cause mechanical compression of the urethra.
    • Similarities: mechanical obstructive symptoms.
    • Differences: penile cancers should be evident on examination either on inspection (as a visible growth) or palpation (of a lump within the body of the penis).

In women:
  • Vaginal prolapse (e.g. cystocoele or urethrocoele).
    • Similarities: incomplete emptying of bladder with storage symptoms of frequency and recurrent UTIs.
    • Differences: incontinence more common with prolapses and usually not as many voiding symptoms, presence of prolapse on examination, absence of causative factors for strictures in history.

In both:
  • Overactive bladder.
  • Similarities: patients may present with urinary frequency, which can be the most troubling symptom for both conditions.
  • Differences: urgency is usually the main symptom in overactive bladder and is much less common in the presentation of someone with a urethral stricture. Overactive bladder may also cause incontinence which is much less common with strictures.

Management

Management options recommended by the British Association of Urological Surgeons (BAUS) are tailored to the patient and their symptoms:
  • Observation - may be a viable option in those with mild symptoms where the risks of surgery may outweigh the benefits. Routine monitoring should be offered and further management should be considered if symptoms are worsening, the post-void volume of urine is increasing or the urine flow rates significantly decrease.
  • Urethral dilatation - involves passing a metal rod under anaesthesia to stretch the narrowed area. This may be followed by a course of intermittent self-dilatation or subsequent re-dilatation procedures as the stricture may recur over time.
  • Optical urethrotomy - an endoscopic procedure where a small cut is made into the scar tissue causing the stricture. Risk of recurrence after the first of these procedures is 50% and higher following subsequent procedures.
  • Urethroplasty - a broad term used for open procedures to repair the stricture. These procedures carry higher surgical and anaesthetic risks but have a lower recurrence rate than the above, less invasive options.
  • Long-term urethral or suprapubic catheters - often an option for those whose comorbidities preclude surgical management.
  • Perineal urethrostomy - useful in men who have multi-segment strictures with healthy prostatic and bulbar urethral segments. Involves bringing the urethra out to an opening in the perineum. Less complicated than urethroplasty and suitable for those in whom the surgical risks outweigh the benefits.

Complications

Complications that may arise when leaving urethral strictures untreated include:
  • Chronic urinary retention, which may lead to:
    • Recurrent urinary tract infections
    • Hydronephrosis, which can damage the kidneys leading to chronic kidney disease
  • More unusual complications may include:
    • Acute urinary retention - usually if other factors cause local swelling in an area where the urethra is already narrowed (e.g. infection, post-radiotherapy)
    • Urethral cancer