[Applied anatomic study of the pudendal-thigh flap and establishment of flap model]

To investigate the anatomic base of the pudendal-thigh flap and establish flap model.

Skin dissection of pudendal-thigh regions was performed on 10 cadavers (20 sides). All afferent and efferent vessels were measured and recorded.

There exist multiple blood supplies of pudendal-thigh flap. Anterior cutaneous branches of obturator artery spread out on middle portion of flap. Piercing site of it is (3.0 +/- 0.5) cm apart from middle line of perineum, (1.7 +/- 0.4) cm from anterior margin of vaginal introitus, (0.6 +/- 0.2) cm from outer fringe of lower pubic rami and (0.8 +/- 0.1) mm in diameter. Posterior labial arteries mainly supply the major labia and constantly anastomose with superficial external pudendal arteries in direct vascular anastomosis in subcutis of major labia. The main stems send out 2-3 lateral branches of posterior labial arteries which distribute to posterior portion of the pudendal-thigh flap.

The major vessels of pudendal-thigh flaps used to form a neovagina are lateral branches of posterior labial arteries and not the main stem itself. Flaps pedicled on the anterior cutaneous branches of obturator arteries may be elevated to repair rectovaginal fistula or small skin defects of perineum and not suited to reconstruct a neovagina as its piercing point of blood vessels is much higher and the location of pedicle is more fixed.