Comparison of different managements of large superficial veins in distally based fasciocutaneous flaps with a veno-neuro-adipofascial pedicle: an experimental study using a rabbit model.

The role of large superficial veins in the survival of a distally based fasciocutaneous flap with a veno-neuro-adipofascial pedicle was studied in a rabbit model. A sural veno-neuro-fasciocutaneous flap model (6 x 2 cm) with a distally based lesser saphenous veno-neuro-adipofascial pedicle (1.5 cm) was established. Fifteen rabbits were randomly divided into three groups with 10 flaps in each group. In group I, the distal lesser saphenous vein was left open (venous inflow remained) after the flap was raised. In group II, the lesser saphenous vein was ligated in the pedicle (no venous inflow). In group III, the venous pedicle was left open in the pedicle, and the proximal end was microsurgically anastomosed to the recipient vein (outflow established). Intravenous pressure, flap survival, and histology were examined. The results showed that the values of intravenous pressure in group I were significantly higher than in group II (P < 0.001). The mean flap survival rate of group III (94.5%) was significantly higher (P < 0.001) than of groups I (22.7%) and II (55.5%). Histology showed that the lesser saphenous vein in group I was extremely dilated and filled with thrombosis. This experiment demonstrated that establishing a superficial venous outflow channel by anastomosis at the proximal end, or interrupting the inflow channel by ligation at the distal pedicle, may significantly improve the survival rate of distally based veno-neuro-fasciocutaneous flaps.