Anatomical Study Of Reverse Insular Flap Of Medial Sural Cutaneous Artery

Objective: In order to research the anatomical characteristics and blood circulation mode of reverse insular flap of medial sural cutaneous artery. Methods: 50 Normal adults` fresh lower extremities from 25 cadavers were observed and measured by means of traditional dissection, de-palletization and poly vinyl chloride artery pipeline foundry on the origin, path, length, diameter, branch number, nerve distribution and superficial projection of medial sural cutaneous artery. Results:Most of medial sural cutaneous artery comes from poplineal artery(81.82%), and some of them comes from lateral sural cutaneous artery(9.09%), posterior tibial artery(2.27%) or medial sural artery(2.27%). (9.09%). Only a few was wanted of medial sural cutaneous artery(4.55%). The original points were 36.4±16.9mm superior of head of fibula and the mean diameter of medial sural cutaneous artery was 1.03±0.40mm in the origination. Medial sural cuataneous artery ended by arterial arch anastomosing with perforating branch from posterior tibial artery at the permanent position in 143.1±38.8mm superior of lateral melleolus. And the diameter of the arterial arch was 0.63±0.19mm. With medial sural cutaneous nerve, medial sural cutaneous artery went down through the sulcus between medial and lateral heads of sural muscle. Medial sural cutaneous artery laid out 5~8 branches while going down in posterior surface of leg. Thebranches anastomosed with the perforating branches of the posterior tibial artery which laid out 2~5 perforating branches in the superficial fascia of medial posterior surface of leg. Most of the superficial branches of the medial sural cutaneous and posterior tibial arteries, their diameters were 0.95±0.36mm, distributed between 200mm superior and 100mm superior of lateral melleous (44.5%). The distributing area of the medial sural cutaneous artery extended to 60~75mm medial of its main trunk. The length of descending branch of medial sural cutaneous artery was 208.2±42.7mm and the length of free pedicle was 260±25.5mm. Medial sural cutaneous nerve was laid from tibial nerve and was join with lateral sural cutaneous nerve to be sural nerve, which was laid from common peroneal nerve, at 160±15.6mm superior of lateral malleous. The superficial projection of the medial sural cutaneous artery was the line between 30mm medial posterior of head of fibula and 25mm medial posterior of lateral malleous and the projection was same with small saphenous vein in leg. Conclusion:The upper part of the medial posterior surface of leg is the best donor area of reverse insular flap, because medial sural cutaneous artery had a permanent position and superficial in leg. Long distance reverse insular flap could be made by axis of medial sural cutaneous artery and pedicle of perforating branch of posterior tibial artery, because medial sural cutaneous artery had more permanent astomosing arch at 147.1±38.8mm superior of lateral malleus. Reverse insular flap of medial sural cutaneous artery could extend superiorly 60~80mm from the basis pedicle length of perforating branch of posterior tibial artery, because the free flap pedicle length of perforating branch of posterior tibial artery was as long as 35±14mm. It made an extension ofapplication of the flap. This kind of flap could repair the lack of soft tissue of knee area and superior part of leg when it is used by means of regular transplant. But it is clinically valuable that the flap could be used as a reverse flap to repair the great area lack of soft tissue in the middle and inferior parts of leg and medial malleus.