Tips & Tricks in Common Surgeries: Fistula Surgery

Introduction

Vesicovaginal fistula (VVF) is a subtype of female urogenital fistula, which is an abnormal fistulous tract extending between the bladder and the vagina which leads to continuous involuntary leakage of urine. Other basic types of urogenital fistula are:

• Urethrovaginal fistula
• Ureterovaginal fistula
• Vesicouterine fistula

Fistula repair is generally complex, and success depends on multiple factors including:

• Fistula type
• Size
• Degree of scarring
• Urethral, ureter involvement
• Competence of surgeon
• Postoperative care and compliance of the patient

Fistula surgery is considered a specialist area. The art of fistula surgery is challenging and demanding owing to the complexity of the cases. The basic principles of repair include adequate exposure of the fistula, mobilization of enough bladder for tension free closure, protection of the ureters, and support of the urethra if deficient.

Tips and Tricks in Fistula Surgery

• Patient positioning is important for good exposure. At times, episiotomy or vaginotomy and head-down tilt of the table are required to improve access, especially in case of high fistula.
• For adequate exposure, the fistula can be brought into view by upward traction using a metal catheter. Access for dissection is facilitated by advancing the fistula incision onto the lateral walls of the vagina. The initial incision around the fistula should only be deep enough to cut the vaginal epithelium but not the bladder or the pubocervical fascia underneath.
• The plane between the bladder and vagina should be developed using a combination of sharp and blunt dissection, and when dissecting, stay close to the vagina keeping as much tissue as possible on the bladder and urethra.
• A large fistula, juxta-cervical fistula, and complex fistula repair have an inherent risk of injuring the ureters. Identification of the ureters and their catheterization are important during the repair. The ureters are sometimes at the edge of a large fistula. A Lagenback retractor placed inside the fistula aids in identification of the ureters. Watch out for double ureters, the incidence of which is 1 in 125.
• Sounding of the bladder for stones is important. Stones should be removed before repair, either through the fistula or by suprapubic cystostomy.
• The probe should be kept in the pin-hole fistula during the dissection, otherwise the track may be lost, or sight of the lumen lost.
• Generally, the fistula is closed transversally but there has to be vertical closure of juxta-urethral fistula to improve the prospect of continence. Other operative steps such as urethral lengthening, repair of pubocervical fascia, and urethral support with a fibromuscular (pubococcygeal) sling, muscle patch (bulbocavernous), etc. are needed to reduce stress incontinence.
• A 5\8- circle needle is helpful in difficult situations, as a continuous suture with good bites may be necessary. One-layer closure of the fistula with delayed absorbable sutures is acceptable when two-layered closure is not feasible.
• In case of vaginal skin defects, or stenosis or occlusion of the vagina, vaginotomy may be needed for better exposure.
• In case of intracervical fistula, the anterior cervix may have to be cut and strong downward traction from the cut ends given for better exposure.
• ‘To graft or not to graft’ is still debatable. Several grafts have been used to protect repair/suture line and support it. The Martius fat graft, Gracilis muscle graft, omental graft, peritoneal graft can be used as an intermediate layer to protect the repair.

The principles for re-repair of fistula are the same as for initial fistula repair. Re-repair procedures should be performed by experienced surgeons. They are difficult mainly due to fibrosis and avascularity; the scar needs excision and grafts, or fibromuscular patches should be sutured over the repair so that it becomes watertight. A muscle patch or graft can be used where there is a leak on dye test if another stich would make it worse.