Vesicovaginal fistula — 12-minute structured oral station

Opening prompt — "Take a focused history from this patient."

Model response — say it in this order: [1]

• "I would start with the leakage pattern: when did it start, is it continuous or only with cough, does she have any dry interval between voids, and how many pads does she use in 24 hours."
• "I would clarify whether she voids in normal volumes or whether the volume has changed — normal voiding with continuous leakage raises the possibility of a ureterovaginal fistula rather than a vesicovaginal fistula."
• "I would ask about the index surgery: indication for hysterectomy, intra-operative findings, any bladder or ureteric injury recognised at the time, and the immediate post-operative course including the day continuous leakage first appeared."
• "I would screen for other continence symptoms — urgency, frequency, nocturia, stress pattern leakage, dysuria — and for skin problems from constant moisture."
• "I would ask about the impact on sleep, work, sexual function and mood, and screen for the psychosocial morbidity that comes with intractable incontinence."[1]

Examiner is listening for: the discrimination between continuous and stress-pattern leakage, the recognition that "voiding normally + leaking" raises ureterovaginal fistula, and the impact question. [1]

Probe 1 — "How would you examine her, and what would you expect to find?"

• "I would perform a Sims speculum examination in the left lateral position to visualise the anterior vaginal wall and the vaginal vault; for a high fistula I would use the knee-chest position or a vaginal retractor."
• "I would look for the fistula opening, the tissue quality around it (clean and pink in iatrogenic cases, ragged and scarred in obstetric or radiation cases), and any associated tissue loss, scarring or urethral damage."
• "I would perform a bimanual examination to assess vault mobility and any pelvic mass or tenderness."
• "If I can see the fistula, I would document its site, size, and distance from the external urethral meatus — that maps to the Goh classification site item and tells me which operative approach to plan."[5]

Probe 2 — "She has continuous leakage, voids normally and the speculum is unremarkable. What next?"

• "The pattern raises ureterovaginal fistula — a leak from one injured ureter into the vagina while the bladder continues to fill from the contralateral ureter and empty normally through the urethra."
• "I would perform the methylene blue dye test: fill the bladder with 200 to 300 mL of dilute methylene blue via a Foley catheter, insert a high and a low tampon, ask her to walk for 15 to 30 minutes. If the tampons remain unstained with a blue bladder, the fistula is not vesicovaginal."
• "I would then give IV indigo carmine and repeat the tampon test; a positive stain on the tampon with the bladder still blue confirms ureterovaginal fistula. The next step is CT urogram to localise the injury."[2][3][4]

Probe 3 — "The tampons stain blue. You have confirmed a vesicovaginal fistula. What is your imaging and timing?"

• "I would arrange cystoscopy to confirm the fistula opening in the bladder, assess the surrounding mucosa and bladder capacity, and exclude calculus or synchronous pathology."
• "I would arrange CT urogram — mandatory before any fistula repair because a missed ureteric injury is the commonest reason for a 'failed' repair."
• "I would counsel her on a minimum delay of 3 months from injury before repair. The biology is that inflammation and oedema need to settle, the slough needs to demarcate, and the tissues need to become pliable again — operating on inflamed tissue is the commonest cause of failure."
• "I would refer her to a centre experienced in fistula repair, treat any UTI, prescribe barrier cream for ammoniacal dermatitis, address contraception and provide psychological support in the interim."[1][5]

Probe 4 — "Three months later, the fistula is a 1.5 cm supratrigonal defect. What operation would you offer and why?"

• "Vaginal Latzko repair — partial colpocleisis — is the appropriate operation for a clean, accessible supratrigonal post-hysterectomy fistula; first-attempt closure 85 to 95% in experienced hands."
• "The technique: excise the epithelialised tract, mobilise the bladder wall from the vagina for 1 to 2 cm in all directions, three-layer closure with absorbable suture, no tension. No interposition is needed for a small clean first-attempt fistula."
• "If there were scarring or recurrence, I would add a Martius labial fat pad flap — vascularised pedicle from the labia majora based on the pudendal artery branches — between the bladder and vaginal closure."[3][6]

Probe 5 — "What post-operative care would you arrange and what would you counsel about continence?"

• "Indwelling catheter for 14 to 21 days, suppressive antibiotic during the catheter period, cystogram before catheter removal to confirm closure, and pelvic rest for 6 to 8 weeks."
• "Clinic review at 6 weeks, 6 months and 12 months — assess closure, continence, sexual function, and plan future pregnancy."
• "I would counsel that closure does not always mean continence — 10 to 30% of complex or large fistulae leave residual stress incontinence from urethral sphincter deficiency. Pelvic floor physiotherapy first, then a sling procedure as a staged option if stress incontinence persists."
• "I would counsel that subsequent pregnancies should be delivered by caesarean section to avoid recurrence."[1][3]

Probe 6 — "She asks whether this could have been prevented."

This is a scored domain — demonstrate reflection and respect out loud: [1]

• "Vesicovaginal fistula after hysterectomy is uncommon — 0.1 to 0.5 per 1000 cases — but when it occurs it is devastating for the woman. Recognising the injury intra-operatively and repairing it in the same sitting reduces the risk of a delayed presentation."
• "Careful dissection of the bladder from the cervix and the vault, identification of the ureters in difficult cases, and avoiding energy sources close to the ureter all reduce the risk."
• "When the injury is recognised post-operatively, prompt investigation with the dye test and CT urogram, timely referral and a planned repair by an experienced surgeon optimise the outcome."[1]