An Experimental Study Of Leaf Dividing Of Venous Flaps In Early Period

Objective: Venous flap, a kind of thin flap with a simple way of operation that do not need to sacrifice a stem artery and not be confined by donor site, have an dominant position on the situation of single artery even deficiency of artery. But the low survival rate circumscribes its clinical application. Different out-flow pedicles can change the hemodynamics of venous blood, return path and blood oxygen content and eventually have a direct impact on the survival of venous flap. This study is to supply a experimental theory to the operative design of venous flap in clinical application, and to improve the survival of venous flap.Methodes: New Zealand white rabbits were divided randomly into three groups. All rabbits were operated on by harvesting a flap from the latero-abdominal wall and then sutured it in the normal position. Group A: normal control group. Group B: flow-through group, the in-flow pedicle vein and the stem out-flow pedicle were retained. Group C: tributary outflow veins of different system group, the in-flow pedicle vein and a different system tributary vein were left open (two veins that collects different site of blood with few communicating branch between themselves are called different system). Survival rate, SOD and MDA of the tissue, histology and ultramicrostructure were examed. The effects of different return path on the survival of the flap and the possible mechanism of action were initially analysised.Results: The mean flap survival rate of group A were higher (P < 0.05) than that of group Band groups C, and the mean flap survival rate of group A and B were significantly higher (P < 0.05) than that of group C. Histology showed that micrangium of fascia layer expanded and akaryocyte stasis respectively postoperatively, especially in group C. These changes in C group ameliorated 24 hours postoperatively. Ultramicrostruture exam showed that there were vacuolar degeneration in cytochondriome with crest disappearing partly , and karyopyknosis with chromatin gathering borderly in group C. These alteration aggravated in turn according to A, B and C group. After 6 days postoperatively, the mean number of microvessels in group A and B has got close normal, but that is significantly lower in group C.