The pudendal thigh flap for vaginal reconstruction: Optimising flap survival* Nicole L.Y. Tham a, Wei-Ren Pan a,*, Warren M. Rozen a, Marcus P. Carey b, G. Ian Taylor a, Russell J. Corlett a, Mark W. Ashton a a Jack Brockhoff Reconstructive Plastic Surgery Research Unit, Room E533, Department of Anatomy and Cell Biology, University of Melbourne, Grattan Street, Parkville, 3050 Victoria, Australia b Frances Perry House, Royal Womens Hospital, Grattan Street, Parkville, 3050 Victoria, Australia Received 23 May 2008 accepted 26 February 2009 KEYWORDS Pudendal thigh fasciocutaneous flap Singapore flap Blood supply Perineum Urogenital reconstruction Perforator flap Summary Background: The pudendal thigh fasciocutaneous (PTF) flap is a useful flap in peri- neal reconstruction, that is reliable when small but is traditionally unreliable when large flaps are raised. Large flaps in particular, are associated with an increased incidence of apical necrosis. Thorough descriptions of the vascular anatomy of this flap have been lacking from the literature, with the current study evaluating this anatomy, aiming to provide the anatom- ical basis for vascular problems and for techniques to maximise its survival. Methods: Five unembalmed human cadaveric pelvis specimens were studied. Lead oxide injec- tant enabled radiographic and dissection analysis of the arterial anatomy of the integument of the perineum. Results: A consistent pattern of vascular supply was found in all specimens. 1: the blood supply to the pelvic floor was supplied sequentially by the posterior labial/scrotal arteries, cutaneous branches from the anterior branch of the obturator artery, and branches from the external pudendal arteries. 2: these vessels ran close to the midline, medial to the PTF flap. 3: the posterior labial/scrotal arteries were deep to the Colles��� fascia and the branches from the obturator artery and external pudendal arteries were located superficial to the Colles��� fascia. Conclusion: This study has demonstrated that the PTF flap is a three vascular territory flap and that the pedicle is situated close to the midline. This may explain why regions of the PTF flap may have a potentially precarious blood supply, and suggests that the PTF flap should be de- signed more medially. Given the third territory of supply to the apex of the flap, a delay proce- dure may help to avoid flap necrosis. �� 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. * Meeting at which the work has been presented: Royal Australasian College of Surgeons and The College of Surgeons of Hong Kong Conjoint Annual Scientific Congress 2008. May 12eMay 16. * Corresponding author. Tel.: ��61 3 9347 5939. fax: ��61 3 9349 2535. E-mail address: w.pan@unimelb.edu.au (W.-R. Pan). ARTICLE IN PRESS 1748-6815/$-seefrontmatter��2009BritishAssociationofPlastic,ReconstructiveandAestheticSurgeons.PublishedbyElsevierLtd.Allrightsreserved. doi:10.1016/j.bjps.2009.02.060 Journal of Plastic, Reconstructive & Aesthetic Surgery (2009) xx, 1e6 + MODEL Please cite this article in press as: Nicole LY Tham et al., The pudendal thigh flap for vaginal reconstruction: Optimising flap survival, J Plast Reconstr Aesthet Surg (2009), doi:10.1016/j.bjps.2009.02.060

Urogenital reconstruction is uniformly complex. Recon- structive techniques are frequently required for perineal reconstruction, used in vaginoplasty, urethral reconstruc- tion and vesico-vaginal or recto-vaginal fistula repair. Many of these procedures require the use of local or distant flaps for reconstruction, of which the pudendal thigh fas- ciocutaneous (PTF) flap, the Martius graft, the gracilis myocutaneous flap and the transverse rectus abdominis myocutaneous (TRAM) flap are common options.1e4 The PTF or Singapore flap is a skin flap based on the groin crease, first described by Wee and Joseph.1 It has been frequently utilised for perineal and vaginal reconstruction and recto- or vesico-vaginal fistula repair, as it has been described as easy to harvest, with inconspicuous donor site scars hidden in the groin crease and most importantly is thin, pliable and sensate.1,5e14 This is advantageous compared to the gracilis myocutaneous flap and TRAM flap, as they are both insensate and bulky. However, PTF flap survival rates have been described as highly unpredictable, varying from 33 to 100%, with apical necrosis being widely reported.15,16 This apical necrosis has limited the widespread use of this flap, particularly when a large flap is required.5,8,15,16 Traditionally, the PTF flap is based on the terminal branches of the internal pudendal artery, the posterior labial orscrotalarteries,withthebaseoftheflaplocatedatthelevel of the posterior end of the introitus. The medial edge of the flaplieslateraltothehair-bearingareaofthelabiamajoraand the tip of the flap is located in the femoral triangle1 (Figures 1 and 2). It is usually tunnelled under the labia medially to be transposed to the site of the defect. Although the vascular supply of the perineal skin was explored in studies by Manchot and Salmon,17,18 who showed the three main arteries supplying the perineum as the internal pudendal, external pudendal and anterior branches of the obturator artery, more focused studies have been lacking from the literature. The current study was undertaken to provide a detailed description of the arterial anatomy of the PTF flap, utilising cadaveric dissection and angiography with a view to ana- lysing why the PTF flap may be unreliable and to maximise the future successful use of this flap. Methods Five unembalmed human cadaveric pelvis specimens were used, comprising two male and three female specimens (age range of 37e90 years mean of 60.5 years). All dissection and radiology was performed at the Jack Brockhoff Reconstructive Plastic Surgery Research Unit, Department of Anatomy and Cell Biology, The University of Melbourne. Institutional ethics clearance was obtained. Angiographic studies The internal pudendal artery, obturator artery and external pudendal artery were selectively injected in four speci- mens. The injection technique was based on the original technique described by Rees and Taylor.19 The injection mixture comprised a radio-opaque combination of powdered lead oxide and gelatine in a 50 C water suspension. In order to achieve a selective injection, limited dissection was first carried out via the pelvic inlet to locate the internal pudendal and obturator arteries, and via the femoral triangle to locate the external pudendal artery. In one pelvis specimen, full-body arterial lead oxide injection had been undertaken, enabling thorough assess- ment without the need for selective injection. Dissection Following lead oxide injection, bony landmarks were marked with lead beads, including the pubic symphysis, ischial tuberosities and the coccyx. The skin, subcuta- neous tissue and pelvic floor muscles of the specimens were then removed en bloc. The pelvic floor muscles were removed from the integument, with each Figure 1 Schematic of pudendal thigh fasciocutaneous flap. Red outline marks traditional flap placement. Figure 2 Pudendal thigh fasciocutaneous flap raised for repair of perineal trauma. Due to size of defect, a smaller flap was raised. (With permission from Dr. Marcus Carey, Frances Perry House). ARTICLE IN PRESS 2 N.L.Y. Tham et al. + MODEL Please cite this article in press as: Nicole LY Tham et al., The pudendal thigh flap for vaginal reconstruction: Optimising flap survival, J Plast Reconstr Aesthet Surg (2009), doi:10.1016/j.bjps.2009.02.060