Pedicled and "flow-through" venous flaps: clinical applications

Recently, the pedicled venous flap and "flow-through" venous flap have been the focus of increasing attention for skin defects of the fingers and hands. For successful venous flap use, the following approaches have been suggested: (1) a pedicled venous flap with preservation of the draining veins alone; (2) a "flow-through" flap with preservation of a flow-through vein in the flap; and (3) an arterialized "flow-through" venous flap which ensures arterial blood flow into the flap. Based on findings that venous blood is helpful in flap survival, the authors made use of the first two flap types, the pedicled venous flap and the "flow-through" venous flap and attempted to establish and clarify reasonable conditions for flap survival. Venous pressure of the finger and elbow was measured and venographies of the finger and hand were also carried out. The following conditions are regarded as essential in successful venous flap procedures: (a) use of a venous flap with a rich venous network; (b) preservation of many "flow-through" veins; (c) harvesting a pedicled venous flap where the veins have afferent (reversed) venous pressure; and (d) anastomosing veins of the "flow-through" flap with recipient veins where high efferent venous pressure exists and differential pressure is observed. Clinical cases are presented and the authors attempt to explain flap failure from previously unknown causes. Conditions for flap harvesting are also discussed.