Saphenous neurocutaneous island flap model in the rat: Evaluation of vascular supply

Neurocutaneous flaps are utilized routinely in reconstructive surgery and e ven more so during the past decade. In this study, the vascular supply of t he neurocutaneous flap in the rat model is presented and evaluated. Thirty- six flaps (3.5 x 3 cm(2)) were dissected on the medial aspect of the leg ba sed on a pedicle of the saphenous nerve, saphenous artery, great saphenous vein, and the surrounding fascial tissues. Animals in the experiment were d ivided into five groups with different circulatory patterns of pedicle diss ections. In group I (N = 12), the pedicle artery, vein, nerve, and fascia w ere preserved. In group II (neurocutaneous flap model, N = 24), the sapheno us artery was transected and the vein, nerve, and fascia were preserved. In group III (intraneural vascular plexus circulation pattern, N = 12), the s aphenous artery and the fascia were transected. In group IV (extraneural va scular plexus circulation pattern, N = 12), the saphenous artery and nerve were transected. In group V (N = 12), the entire pedicle was transected com pletely. Flap survival was evaluated grossly on postoperative day 7, All fl aps survived in group I, but in group II 19 of 24 flaps survived completely , 3 of 24 had partial necrosis, and 2 of 24 were completely necrotic. Compl ete necrosis was observed in all group III flaps. In group IV, 6 of 12 flap s survived completely, 3 of 12 flaps survived partially, and 3 of 12 flaps were necrotic (p < 0.05 vs, group I). Only one flap with partial necrosis s urvived in group V, In group II, the average survival area was not signific antly different from group I (p > 0.05), In conclusion, the saphenous neuro cutaneous flap in the rat is a reliable microsurgical model. The saphenous neurocutaneous flap is commonly supplied by both the intraneural and extran eural vascular plexus, and although the latter is more important, neither p rovides sufficient vascular supply on its own.