Microcirculation of a venous flap: An experimental study with microspheresin rabbits

In recent years, it has been found that maintenance of venous circulation a lone may support a small flap with no direct arterial inflow. The clinical application of a venous flap has potential in the field of microsurgery. Th e purpose of this study was to evaluate the haemodynamics within a pedicled venous flap in rabbits, compared with those of a composite graft. Pedicled venous flaps and composite grafts were raised from the abdominal walls of 30 adult New Zealand rabbits. Flap survival was measured and recorded and b lood flow studies with microspheres were done for seven days. The viability of the pedicled venous flaps was much better than that of the composite gr afts. At two weeks 24 of the venous flaps (80%) showed more than 75% surviv ing, but 29 (97%) of the composite grafts had less than 25% surviving. The results suggest that the blood flow through a patent vein maintained in a v enous skin flap can provide enough nutrients for the flap to survive during the initial three days until neovascularisation. The venous flap receives more blood flow than a composite graft. We conclude that a venous flap depe nds on blood supply from the axial vein in addition to neovascularisation t o maintain its survival.