Pudendal Thigh Flap (Mathes&Nahai)
Flap type – fasciocutaneous type A
Pedicle – posterior labial artery from internal pudendal; 10-12cm/1mm; internal pudendal is regional source for perineum through inferior rectal and perineal arteries; perineal artery courses from posterior to anterior and from deep to superficial; after transverse perineal artery branches off at the level of the anus, the perineal continues as the posterior labial artery running from posterior to anterior between the groin crease and labia majora just above deep fascia over adductor muscles; distally there is a network of anastomoses between the posterior labial artery and terminal branches of deep external pudendal and medial circumflex femoral.
Sensory innervation through posterior labial branches from pudendal nerve (S2-S4) and posterior cutaneous nerve of thigh.
Landmarks – posterior border of vagina marks posterior margin and base of flap and the lateral border of labia majora marks the medial border; centered on the groin with the distal margin at the femoral triangle
Raise – lithotomy position with legs in stirrups; incise through fascia to level of medial thigh adductors; flap 6cm by 15cm allows direct closure; pedicle running longitudinally within flap just above the deep fascia
Coverage – medial transposition for perineal coverage and vaginal reconstruction