RESUMEN
Objective To investigate the mechanism of venous reverse-flow flap in the differentperiod after operation.Methods The rabbits wero randomly allocated into 3 groups.In group A,including saphenous artery and venae commutante.In group B,saphenous artery without venae commutante.In group C,surface seeping and saphenous artery and venae commutante.Flap appearance,intravenous pressure,vessel diameter,mierocircular and histological examination were mea8ured.Results The difference of introvenous pressure between group A.B and C was obvious.Reverse flow WaS found in group A and C group through microcirculation observation 2 hours post-operation.Venous valve lose efficacy while the vessel diameter wes at maximum just after the pressure peak.Conclusion Venous retrograde return in reverse-flow island flaps can be achieved more easily through"incompetent valves route"than through "communicating and collaterall by pass route".By pass route is a supplementary way.Surface seeping Can slighfly relieve the venous pressure but can cause infection.