Pudendal Thigh Flap for Repair of RectovaginalFistula
S Sathappan, FRCS, M A I Rica, MS
Department of Surgery, Faculty of Medicine, Universiti Kebangsaan Malaysia, ]alan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras,Kuala Lumpur
Recto-vaginal fistulae (RVF) poses a challengingproblem to the surgeon as there are a variety of surgicalprocedures that may be employed in its repair. Causesof RVF include obstetrical injury, Crohn's disease, post-operative fisulas and cryptoglandular disease. Amongstthe choices of surgical repair are mucosal advancementflap, rectal sleeve advancement flap, fistulotomy withoverlapping sphincter repair and fibrin glue.
The pudendal thigh flap was originally used bilaterallyfor surgical reconstruction of the vagina. It was firstdescribed in 1989 by Wee and]oseph' who called it theSingapore flap. In 1998 Cardon et at' described the useof a unilateral neurovascular pudendal thigh flap in thetreatment of complex rectovaginal fistulae.
Repair of rectovaginal fistula is planned according tothe anatomic and clinical features of the defect. Simplefistulas, less than 2.5cm and located in the mid to lowanal canal occurring secondary to trauma or infection,are usually repaired through transvaginal, transanalapproach or through transformation into a completeperineal laceration followed by perineal repair.
This article presents two cases of rectovaginal fistulapost surgery; one which had two rectal sleeveadvancement flaps that failed, the second case of a 20year history of fistula but with no attempted surgicalrepair. Repair with unilateral pudendal thigh flap wascarried out for both these cases and to date has beensuccessful.
CaselA 23 year old lady who underwent an ultra low anteriorresection with stapled anastomosis and a covering loopileostomy three years previously for megacolon. Shedeveloped a rectovaginal fistula a year after theoperation for which she had had two mucosal sleeveadvancement flaps carried out, both of which failed.She was referred to us for an alternative surgical option.The patient underwent a pudendal flap repair withclosure of the fistula with bilateral 'turnover' vaginalflaps from adjacent tissue. Intraoperatively, there wasa rectovaginal fistula with a diameter of about l.Scmextending from above the dentate line to Scm beyondthe introitus.
The operative time was two hours and there wasminimal blood loss. Postoperatively, recovery was
This article was accepted: 8 January 2006 . . . ..Corresponding Author: Rica Farah Muhd Abd Ichihashi, Department of Surgery, Faculty of MedIcine, Umversltl KebangsaanMalaysia, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur
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uneventful. The flap took well with presence ofsensation to pin prick on the 3rd post operative day.After four months of follow-up this sensate flap hasproven successful but there was hair growth on theflap.
ease 2A 41 year old lady who is a known case of vaginalatresia had vaginoplasty at age 21. This wascomplicated by vaginal stenosis which required asecond corrective surgery, after which a vaginal mouldwas left in-situ. The patient had several follow-up visitsbut soon defaulted follow-up care. She used the mouldon and off for almost IS years not seeking any medicalhelp even after noticing that the mould wasoccasionally stained with faeces. When she finallysought medical help she was diagnosed to have a largerectovaginal fistula measuring IScm by Scm. Almostthe whole posterior wall of the reconstructed vaginawas fistulous. Despite being such a large vaginaldefect, it was possible to use bilateral vaginal 'turnover'flaps to close it and a right pudendal flap was 'on-layed'over the resultant raw surface generated. A coveringcolostomy was done.
The operative time was about two hours for the flaprepair with minimal blood loss. Two months aftersurgery, the flap had healed well.
The mapping of the right pudendal flap for both thesecases was done on the medial aspect of the right thigh.The borders of the flap are demarcated as such;superiorly the groin crease just beyond the labia majora
(Figure I-A), inferiorly just above the femoral triangle(Figure I-C) and the base of the flap at the posteriormargin of vagina (Figurel-B).
Subfascial dissection was done to include theepimysium of the adductor muscles and the de-epitheliazed flap was tunneled under the labia (Figure2). The flap filled the vaginal defect and functioned asthe posterior vaginal wall. The vaginal side of thefistula was repaired after excising the fistulous tract.Repair was done with local turnover flap of vaginaltissue incised lcm from the margin and dissected fromthe underlying perirectal tissue.
The pudendal thigh flap is a sensate fasciocutaneousflap based on the posterior labial vascular bundle andinnervated by the posterior labial branch of thepudendal nerve. There are multiple blood supplies ofpudendal-thigh flap but the major vessels of pudendal-thigh flaps used to form a neovagina are the lateralbranches of the posterior labial arteries and not themain stem itself.
Because of its abundant blood supply, the pudendalthigh flap is robust. In fact, even in patients who havehad previous irradiation and multiple procedureswhere vascular supply to the flaps were questionable,these flaps have survived'. The rich vascularity of theflap also prevents wound contracture and moreimportantly infection which would lead to possible
Fig 1: Demarcation of potential flaps with probethrough rectovaginal fistula. Bladder catheter insitu.
Fig 2: Subfascial dissection of flap.demonstrating tunnel under labia.catheter in-situ.
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recurrence of fistulae. In addition, the thigh flap is asensate flap, receiving innervation through theposterior labial branches of the pudendal nerve andthrough the perineal rami of the posterior cutaneousnerve of the thigh. It has been reported to have similarerotic sensation as the perineum and the upper thigh.
The cosmetic advantage of this flap is that the donorsite can be closed primarily, leaving an inconscpicuouslinear scar which in time, becomes hidden in the groincrease. This is in contrast to the more complicatedgracilis myocutaneous flap.
Pudendal Thigh Flap for Repair of Rectovaginal Fistula
During follow-up, we found that one patient wasexperiencing hair growth in the vagina. This wastroublesome and caused some discomfort. Theobservation of hair growth after pudendal thigh flapshave been reported' and preoperative depilation havebeen suggested tQ eliminate this problem.
Most rectovaginal fistulas can be repaired, althoughrepeated operations may be necessary. We suggest thatuse of a pudendal thigh flap should be considered inthe management of a complex rectovaginal fistula.
1. Wee JTK, Joseph VT. A new technique of vaginalreconstruction using neurovascular pudendal-thigh flap:A preliminary report. Plast Reconstr Surg. 1989; 83: 701.
2. Cardon A, Pattyn P, Monstrey S, et at. The use of anunilateral pudendal thigh flap in the treatment ofcomplex rectovaginal fistulae. Br J Surg. 1999; 86: 645.
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3. Giraldo, E, Gaspar, D., Gonzalez, C., et at. Treatment ofvaginal agenesis with vulvoperineal fasciocutaneousflaps. Plast. Reconstr. Surg. 1994; 93: 131.