A stricture or narrowing in the urethra (the tube that drains the bladder) is an uncommon condition, especially in a woman. Female urethral strictures represent a cause of bladder outlet obstruction in 4-13%. There is no widely accepted definition, some of them are:
- Fixed anatomical narrowing of the urethra (<14Fr), of inadequate calibre to allow catheterisation.
- Proximal urethral dilatation with distal narrowing on radiological contrast study.
There is no consensus on investigation and management as well.
The causes include:
- Instrumentation from previous catheterisation or cystoscopy.
- Prior urethral surgery.
Patients can present with a variety of symptoms:
- Voiding symptoms – Straining, hesitancy, poor flow, intermittency, painful voiding, terminal dribbling, sensation of incomplete emptying.
- Storage symptoms – Urinary frequency, urgency, urge incontinence, nocturia. This may be due to a secondary overactive bladder from outlet obstruction.
- Urinary tract infections.
- Urethral pain – ‘Urethral Syndrome’.
- Difficult catheterisation.
- Urinary retention.
Some of these tests may be ordered by your clinician.
- Mid-stream urine specimen to check for infection.
- Ultrasound to check if you are emptying the bladder properly.
- Uroflow test where you are asked to pass urine into a calibrated funnel. Typically, it may show a protracted, plateau-shaped voiding curve, slow flow, and low peak flow rate.
- Urethroscopy / Cystoscopy – this allows a direct visualisation of the stricture but may not be possible in severe strictures.
- Retrograde vs. antegrade urethrogram – this is a contrast study that aims to assess the location and width of the narrowing caused by the stricture. A retrograde urethrogram is not practical in females due to the short urethra. An antegrade urethrogram is done via suprapubic access or 5Fr catheter transurethrally, during which the bladder is filled up and the patient is then asked to void. Typically, the findings include an open bladder neck, a dilated proximal urethra, and a narrowing at a strictured area (‘wine glass’ configuration).
- MRI pelvis – this is usually done to rule out other pathology such as a urethral diverticulum, and abscess. It can assess for periurethral fibrosis. However, its diagnostic value is probably low and therefore is not commonly done.
- Video Urodynamics – this test allows the assessment of bladder dysfunction together with contrast visualisation of the stricture. It can look for evidence and degree of bladder outlet obstruction, the presence of secondary detrusor overactivity, and assess the location and length of the stricture.
Your clinician may perform a vaginal examination looking for:
- Meatal stenosis.
- Pelvic organ prolapse.
- Periurethral abnormalities.
- Quality of surrounding organs looking for vaginal mucosa atrophy or lichen sclerosis.
Treatments include non-surgical and surgical options.
Non-surgical treatment is suitable for milder strictures and usually involves the application of topical intravaginal oestrogen (if there is no contra-indication). This is helpful in post-menopausal women who suffer from vaginal mucosal atrophy which can cause a stricture, especially at the opening of the urethra (meatus).
Surgical treatments range from urethral dilatation to more formal repairs (urethroplasty).
This involves gently stretching the stricture with graduated blunt dilators called sounds. It may be suitable in some patients especially if it is a first presentation. The overall success rate, however, is not high (47% at 43 months). This is worse if there is a history of previous dilatation (27%). In some patients, regular dilatation may be a suitable option as it is relatively non-invasive.
The stricture is visualised and incised via a small camera (cystoscope). Uncommonly this can result in incontinence in women.
The overall success rate of a formal repair with urethroplasty is very high (80% to 94% success rate at 25 months).
There are various techniques described in the literature, and the one used may depend on the patient’s overall status, stricture characteristics and surgeon’s skills and preference. A flap (local tissue with preserved blood supply pedicle) or a graft (harvested tissue from another area of the body) may be used. A graft can be obtained from nearby vaginal mucosa or from inside the sidewall of the mouth (buccal mucosa). The stricture can be repaired either dorsally or ventrally, with onlay or inlay techniques. These have different complication profiles.
Possible complications include stress urinary incontinence, fistula (abnormal connection from the urethra to the outside vaginal wall causing leakage), recurrence, graft sacculation, inward vaginal voiding, sexual dysfunction and neurosensory deficit.
Sometimes an additional protective layer (Martius flap or fascia sling) may be placed surgically over the repaired area to reduce the risk of fistula formation.
An indwelling catheter is usually left in place for a few weeks post-operatively for healing to occur.
Read A/Prof Gani’s publication on his technique on a ventral inlay oral mucosal free graft urethroplasty.
The features of this technique are:
- High success rate.
- Vaginal sparing.
- Requires minimal urethral mobilisation.
- Reduces potential complications of operating through anterior vaginal wall such as fistula formation.
- Reduces risk of injury to sphincter mechanism which can cause stress urinary incontinence.
- Avoids operating near the neurovascular bundle of the clitoris.
- Avoids using unhealthy vaginal tissue especially if there is local inflammation.