An experimental continuestudy of venous drainage in reverse-flow island flap

：Objective To investigatethe mechanism of venous reverse-flow flap in the differentperiod after operation.MethodsThe rabbits wero randomly allocated into 3 groups.In group A,including saphenous arteryand venae commutante.In group B,saphenous artery without venae commutante.In groupC,surface seeping and saphenous artery and venae commutante.Flap appearance,intravenouspressure,vessel diameter,mierocircular and histological examination were mea8ured.ResultsThe difference of introvenous pressure between group A.B and C was obvious.Reverse flowWaS found in group A and C group through microcirculation observation 2 hourspost-operation.Venous valve lose efficacy while the vessel diameter wes at maximum justafter the pressure peak.Conclusion Venous retrograde return in reverse-flow island flapscan be achieved more easily through"incompetent valves route"than through"communicating and collaterall by pass route".By pass route is a supplementaryway.Surface seeping Can slighfly relieve the venous pressure but can cause infection.