An experimental study on the venous drainage of mini tissue flaps
XING Jin-feng SHI Tie-jun ZHAO Wei CHEN Zhong CAO Yang LIN Ping JIANG Dan-sheng WANG Zhi-ming NI Dong-liang YANG Ning Department of Orthopaedics,Central Hospital of Jinhua,Zhejiang 321000,China
Objective To set up an animal model of mini tissue flaps and explore the mechanism of retrograde vein drainage.Methods A mini tissue flap based on the saphenous artery(flap size:1.0 cm×1. 0 cm)was created on both hind limbs of 30 Sprague Dawley rats.The left and right hind limbs of each rat were randomly assigned into group 1 and 2.In group 1,the flaps were elevated and the saphenous artery and its accompanying veins were kept in situ.In group 2,the flaps were elevated and only the saphenons artery were kept in situ,while its accompanying veins and other superficial veins were ligated.Survival of the flaps,their appearance and consistency were observed.Reconfiguration of venous drainage of the flaps was evaluated by angiography.Results Flaps of group 1 had normal skin color at postoperative day 1.Only 3 flaps in this group showed mild swelling which subsided at pestoperative day 2.All flaps had normal consistency.All the flaps of group 2 showed mild cyanosis and obvious swelling at postoperative day 1.There was tension of the flaps. Swelling of the flaps decreased and color of the flaps turned normal at postoperative day 2.Tension of the flaps also reduced.For swelling of the flaps,the difference between the two groups were statistically significant in the first and second days postoperatively(P0.01),but insignificant in the 3,7,9 and the 14 days postoperatively. For flap survival,in group 1 all flaps survived with normal skin color,good appearance and elasticity except one flap presented about 0.1 cm marginal skin necrosis.In group 2,there were 2 flaps with about 0.1 em marginal skin necrosis and 3 flaps with complete necrosis.The survived flaps had normal skin color and no swelling,but their appearance and elasticity were slightly worse than that of the flaps in group 1.Conclusion The survival mechanism of mini tissue flaps is different from that of conventional flaps.Restoration of venous drainage relies on collateral anastomosis between the flap and its tissue bed and surrounding margins in the first 3 postoperative days.When arterial flow is patent,mini tissue flaps still have a high survival rate even if the venous flow is obstructed due to a failed vein anastomosis.However a good venous anastomosis is required to ensure good flap appearance and consistency.
【CateGory Index】： R622
【CateGory Index】： R622