V22 - Gracilis Muscle Flap Interposition For Pouch-Vaginal Fistula

Purpose/Background: Pouch-vaginal fistulas are a rare but challenging complication following restorative proctocolectomy with ileal pouch-anal anastomosis. These fistulas are frequently refractory to conventional repair, especially in the context of prior pelvic surgery, radiation, or multiple failed attempts. Gracilis muscle flap interposition is a well established technique for the treatment of complex fistulas.

Methods/Interventions: This video demonstrates a stepwise technique for gracilis muscle flap interposition in the management of a pouch-vaginal fistula. Informed consent was obtained, and the video was filmed using an iPhone camera. Operative reports, surgical history and clinical notes from the chart were reviewed.

Results/Outcomes: This is a 49-year-old female with a history of refractory ulcerative colitis who previously underwent total colectomy with ileal pouch–anal anastomosis, followed by pouch revision with transanal mucosectomy, handsewn anastomosis, and subsequent ileostomy reversal. One month later, she presented with passage of stool per vagina. Pouchoscopy, pelvic MRI, and examination under anesthesia (EUA) were performed, and a pouch-vaginal fistula was diagnosed. She was initially managed with a diverting loop ileostomy, followed by gracilis muscle flap interposition. The patient was placed in the modified lithotomy position, a 5 cm incision was made overlying the neurovascular pedicle of the right gracilis muscle. The neurovascular pedicle was identified using a neuromuscular stimulator. A 4 cm incision was made distally over the gracilis tendon where a modified Bunnell technique using two Ethibond sutures was used. The tendon was mobilized using a 5 mm handheld harmonic scalpel, so that the muscle could be delivered into the proximal incision and tunneled towards the ipsilateral right side of the anus. A 19 mm Blake drain was left along the base of the muscle harvest site, and the wound was closed in layers. The patient was then carefully repositioned in the prone jackknife position. A 120° anterolateral circumanal incision was made and deepened to the level of the anterior peritoneal reflection, being careful bring the dissection at least 4 cm cephalad to all fibrotic tissue. An advancement flap closure was then undertaken on the anal and vaginal side after debridement of the fistula. A series of six 2-0 PDS sutures were then placed through the levator muscles bilaterally, and the gracilis muscle was sutured in place so that the thickest portion of the muscle was between the fistula closure sites. A 19 mm Blake drain was left at the apex of the wound and closed. The standard postoperative regimen is bedrest for three days in an adduction splint, physical therapy on postoperative day 4 and discharge the following day. The drains are removed once the output is serous and < 10-20 cc / day. If one or both drains are not removed before discharge, the patient is sent home with a week of oral antibiotics and followed up in clinic once completed to evaluate for removal. Patients are typically seen 6-weeks postoperatively, and the stoma is closed once there is adequate healing.

Conclusion/Discussion: Gracilis muscle flap interposition is a well established and safe surgical option for complex or recurrent pouch-vaginal fistulas. It should be considered in patients with multiple prior failed repairs, history of pelvic radiation, or extensive scarring. The technique offers significant improvement in quality of life and continence and should be considered as a treatment option for refractory pelvic fistulas.