Meatal Stenosis

Meatal stenosis is narrowing of the external urethral meatus, impairing the urinary stream. It occurs almost exclusively in circumcised boys and men.

After circumcision, loss of the foreskin leaves the meatus exposed to the diaper and clothing. This causes chronic meatal inflammation (meatitis), ulceration of the ventral meatal lip and scarring, which narrows the meatus (acquired meatal stenosis).

Peak incidence is 3 to 7 years in boys (in 5 to 20 percent of circumcised boys depending on series). In adults it is associated with balanitis xerotica obliterans (lichen sclerosus). It is also associated with hypospadias repair, and with urethral catheterisation and instrumentation.

Congenital meatal stenosis is rare (mostly with hypospadias). In girls, distal urethral stenosis is rare and is associated with recurrent urinary tract infection.

The narrowed meatus gives rise to a high pressure and a thin, forceful stream directed upward or dorsally, with spraying. In severe cases it causes bladder trabeculation, residual urine, infection and hydronephrosis.

• A narrow, thin, forceful, deflected (upward and dorsal) urinary stream, with straining, prolonged voiding, spraying and a pinpoint meatus seen at examination.
• Dysuria, frequency, urgency, a burning sensation, terminal haematuria (blood spots on diaper or underwear), enuresis, and urinary tract infection.
• Painful micturition with crying, or a child who strains and holds penis.
• Abnormal stream direction, with the child being unable to aim.
• Blood spotting at the meatus, a pale, whitish or scarred meatus (lichen sclerosus in adults), and a ventral web.
• Chronic obstruction: hydronephrosis, bladder wall thickening, and post-void residual.

• Clinical inspection: a pinpoint meatus, a ventral meatal web, and an inflamed or ulcerated meatus. Observe the stream (thin, forceful and upwardly directed).
• A normal meatus should easily admit an 8 to 10 Fr feeding tube in a child and a 24 Fr sound in an adult.
• Urinalysis and urine culture, urine flow rate (flow below 10 mL/second in adults, with plateau shaped flow), post-void residual.
• Renal and bladder ultrasound for hydronephrosis and bladder thickening if the symptoms are significant; voiding cystourethrogram in children with recurrent infection to exclude associated anomalies.
• In adults with lichen sclerosus: biopsy of the whitish plaques to confirm and to exclude malignancy.

• Meatal dilation and topical therapy: mild stenosis in a young child may be treated with topical corticosteroid (betamethasone 0.05 percent or hydrocortisone cream applied twice daily for 4 to 6 weeks) to reduce inflammation.
• Combine this with gentle dilation with meatal dilators (in clinic with topical lidocaine 2 percent gel). Recurrence is common.
• Meatotomy is the definitive treatment. Divide the ventral meatal web and stenotic segment, extending the incision into the normal calibre urethra (typically 3 to 5 mm).
• In children, meatotomy may be done under topical anaesthetic in clinic. Use a haemostat to crush the ventral meatus for 1 to 2 minutes, then cut with fine scissors.
• Alternatively, in older children, do it under general anaesthesia with suture of the mucosal edges to the skin using 6-0 absorbable suture (meatoplasty) to prevent re-adhesion.
• Postoperative care: apply antibiotic ointment (bacitracin, mupirocin) or petrolatum to the meatus twice daily for 2 to 4 weeks. Gently spread the meatal lips to prevent restenosis, and advise warm baths.
• Success is 90 to 95 percent, and restenosis in 5 to 10 percent occurs.
• Meatoplasty: when meatotomy fails, to reduce recurrence in adults: ventral meatoplasty with mucosal advancement, or the use of a buccal graft in lichen sclerosus.
• Lichen sclerosus (balanitis xerotica obliterans) in adults: clobetasol propionate 0.05 percent ointment twice daily for 4 to 12 weeks then taper, for meatitis.
• Add meatotomy or urethroplasty (using buccal mucosa) when stricture involves the fossa navicularis. Circumcise if foreskin is present and diseased. Follow up long term, since there is a small risk of squamous cell carcinoma.
• Girls with distal urethral stenosis: dilation, topical oestrogen (estradiol 0.01 percent cream) and urethrotomy.
• Post-operative monitoring: observe stream and symptoms at 2 to 4 weeks and repeat uroflowmetry; ultrasound for hydronephrosis if it was present before; follow up urine cultures.
• Prevention: protect the meatus after circumcision with petrolatum application for the first weeks, and early treatment of meatitis and diaper dermatitis.