# Urinary Fistulae > NEET-PG Surgery notes on urinary fistulae covering vesicovaginal fistula causes in India, dye tests, timing of repair and flaps. - Canonical URL: https://prepelephant.com/topics/neet-pg/surgery/urinary-fistulae - Exam / course: NEET-PG · Subject: Surgery - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Urinary Fistulae", PrepElephant, https://prepelephant.com/topics/neet-pg/surgery/urinary-fistulae ## Direct answer Urinary fistulae are abnormal communications between the urinary tract and adjacent organs or skin, of which the vesicovaginal fistula (bladder to vagina) is the archetype — in India still overwhelmingly obstetric, from prolonged obstructed labour compressing the bladder against the pubic symphysis, whereas in high-income countries post-hysterectomy surgical injury dominates. The signature symptom is continuous urinary leakage per vaginam with excoriation and amenorrhoea-related social devastation; diagnosis is confirmed by dye tests (vaginal tampon after instilling methylene blue into the bladder) and cystoscopy, with imaging of the upper tracts for associated ureteric injury. Small, early fistulae may heal with continuous catheter drainage for a few weeks; established fistulae are repaired surgically — transvaginally for low, accessible fistulae and transabdominally for high or radiation-injured ones — in layers with interposition of healthy tissue such as a Martius fibrofatty flap, giving success rates of 85-95 per cent for first repairs. ## What you must remember - Obstetric VVF mechanism: obstructed labour lasting days compresses the bladder base and anterior vaginal wall against the symphysis, causing pressure necrosis; the tissue sloughs 3-7 days after delivery, leaking appears, and the "fistula quartet" includes urinary dermatitis, secondary amenorrhoea, foot drop (prolonged squatting labour) and social ostracism. - Surgical VVF after hysterectomy: injury at the vaginal cuff or from a bladder burn, leaking typically 5-14 days post-operatively; ureteric fistulae present similarly but leak continuously regardless of catheterisation. - Diagnosis: methylene blue instilled into the bladder stains a vaginal tampon (VVF); if the tampon stains orange with intravenous indigo carmine or pyridium instead, suspect a ureterovaginal fistula — this dye distinction is a classic exam sequence. - Cystoscopy defines fistula site, size and relation to ureteric orifices; a fistula close to the ureteric orifice may need ureteric reimplantation at repair. - Timing: a fresh, small fistula gets 4-6 weeks of continuous catheter drainage first, which heals a minority; established fistulae are repaired after 3 months of tissue maturation — earlier repair is favoured by some centres for clean surgical fistulae. - Repair principles: tension-free watertight closure in layers (bladder and vagina separately), non-overlapping suture lines, drainage of the bladder for 10-14 days, and interposition of healthy tissue — Martius flap (labial fibrofatty graft) transvaginally, omentum transabdominally, especially after radiation. - Route: transvaginal (Latzko partial colpocleisis for small post-hysterectomy fistulae; flap-splitting repair) versus transabdominal (O'Connor technique opening the bladder) for high, large, multiple or irradiated fistulae. - Complications of neglected fistulae: chronic renal disease from associated ureteric obstruction, recurrent UTI, calculi, and the psychological injury — fistula repair in India is as much social surgery as urology. ## A typical case from presentation to repair A 23-year-old primigravida delivered at home after two days of obstructed labour; the baby was stillborn, and five days later she began leaking urine continuously, soaked despite everything. Walk her care. Step 1: confirm and map — pelvic examination shows an excoriated vulva and a 1.5 cm fistula just above the trigone visible through a speculum; dye test positive (blue tampon), cystoscopy confirms a mid-vaginal bladder fistula with both ureteric orifices visible and away, and an ultrasound excludes hydronephrosis. Step 2: stabilise and support — continuous catheter (a small proportion of early fistulae close in 4-6 weeks), barrier cream for the skin, treatment of infection, iron and nutrition, and counselling about the condition not being her fault; in India, fistula camps and dedicated centres support women abandoned by families. Step 3: repair at about three months through a transvaginal flap-splitting approach: circumferential incision, wide mobilisation of bladder from vagina, tension-free closure in two layers with a Martius flap interposed, catheter for two weeks. Step 4: post-operative discipline — the catheter must never tug (fix to abdomen in women), anticholinergics reduce spasms, and removal at two weeks follows a dye test. Step 5: future pregnancies by caesarean section, since a repaired bladder does not withstand labour — and that single sentence is worth a mark in every exam. ## Where students slip The dye-test logic is the most fumbled sequence: blue dye in the bladder staining the tampon proves vesicovaginal; intravenous coloured dye (indigo carmine classically) staining the tampon without intravesical dye proves a ureterovaginal component — remember the direction of dye administration. The second slip is timing: repairing an inflamed, infected fistula within days of injury fails and converts a repairable fistula into a recurrent one; the discipline of catheter drainage first and surgery after maturation is the tested answer. Third, ureteric proximity: a fistula abutting the ureteric orifice needs stents and possible reimplantation — forgetting this turns a leak into an obstructed kidney. Fourth, radiation fistulae: never close irradiated tissue without vascularised interposition (omentum), and success rates drop markedly — examiners use these cases to test judgement, not technique. Finally, the obstetric legacy: foot drop and amenorrhoea accompanying a fistula point to obstructed labour, not surgery, and the management plan must include the social worker and the future caesarean, not only the bladder. ## Frequently asked questions ### What causes vesicovaginal fistula in India versus the West? In India, prolonged obstructed labour with pressure necrosis still predominates in rural areas; in high-income countries, gynaecological surgery, especially hysterectomy, is the leading cause. ### Which dye tests distinguish VVF from ureterovaginal fistula? Methylene blue instilled into the bladder staining a vaginal tampon confirms a vesicovaginal fistula; a tampon stained by intravenous dye with a negative bladder test indicates a ureterovaginal fistula. ### When should a VPF be definitively repaired? After about three months of tissue maturation — though an initial 4-6 week trial of continuous catheter drainage may heal small early fistulae, and selected clean surgical fistulae are repaired sooner. ### What is a Martius flap? A labial fibrofatty pedicle graft divided from the labium majus and tunnelled to interpose between the repaired bladder and vagina, providing vascularised tissue that protects the suture line. ### How are future deliveries managed after fistula repair? By elective caesarean section — labour risks disrupting the repair — and this counselling is part of the surgical consent in every woman of childbearing age.