Venous Island Flap for Reconstruction in the Hand

The venous flap uses skin and superficial veins for the inflow and outflow of its blood supply. In hand reconstruction procedure, the venous island flap can provide a natural appearance and function. Also its elevation is easily obtained, the operation is simple, and a thin flap can be formed. From November 2000 to July 2002, we performed unipedicled venous island flap procedure on the hand over exposed bone, tendon or joint in 16 cases of 14 patients. The donor sites were on the forearm in 2 cases and dorsal surface of the hand in 14 cases. Flaps were proximally based in 4 cases and distally based in 12 cases. The sizes of the flap ranged from 4.5 cm(2) to 25 cm(2) and the pedicles were a minimum 3 cm and a maximum 7 cm. During elevation of the flap, the pedicle of the flap included one superficial vein of hand and its perivenous areoalr tissue. On donor site direct closure was performed in 11 cases and a full thickness skin graft was performed in 5 cases. In the cases in which the pedicle length was less than 4 cm, the flaps completely survived whether the base of the pedicle was proximal or distal. However, in the cases of distally based flaps with pedicle lengths greater than 5 cm and large rotation angle, congestion developed frequently. In the latter cases, we could raise the survival rate through external bleeding using heparin. Finally, flaps survived successfully in 14 cases and partial necrosis developed in 2 cases. However, the latter were healed by conservative treatment.

Effect of prefabrication on the survival of venous island flap

There are some attempts to improve the survival of venous island flap, such as delay procedure and pharmacological agents. This study includes prefabrication of vein which could enhance the survival of the venous island flap. The venous island flap was created by a branch of the central vein in rabbit auricle. At 1.5 cm away from the distal margin of the designed flap, the central vein was dissected and transferred under the random part of the future venous flap for 1 week. The survival of prefabricated venous flap was compared with unprefabricated flap 1 week after the flap elevation. The vasculature in the flap were also visualized by microfil cast. The results were as follows: 1. The prefabrication improved the survival of the venous flap significantly. 2. The transferred veins in the prefabricated flap were well visualized 1 week after the flap elevation. In conclusion, it is inferred that the prefabrication enhance the survival of the venous island flap.

Plasmatic imbibition and revascularization in venousisland flap

Several mechanisms about venous flap were proposed. Among them, plasmatic imbibition and early revascularization are supposed to be the most important factors for the survival of venous flap. Many reports about the role of plasmatic imbibition have used silastic sheet or other foreign material to block the plasmatic imbibition so that foreign body reaction might affect the survival of the flap. No experiment has been reported to examine the revascularization directly. We blocked the plasmatic imbibition by marginal resection around the venous island flap and delayed venous island flap and placing it onto the bare cartilage to exclude the effect of foreign body. We also examined the revasularization of the delay and non-delay venous island flap directly using microfil cast. As a result blocking of the plasmatic imbibition markedly decrease the survival of the flap but the survival of delay flap is about five times that of non delay flap. Revascularization was minimal at 1 week postoperative day. It is inferred that plasmatic imbibition is more important than revascularization.

Plasmatic imbibition and revascularization in venousisland flap

Several mechanisms about venous flap were proposed. Among them, plasmatic imbibition and early revascularization are supposed to be the most important factors for the survival of venous flap. Many reports about the role of plasmatic imbibition have used silastic sheet or other foreign material to block the plasmatic imbibition so that foreign body reaction might affect the survival of the flap. No experiment has been reported to examine the revascularization directly. We blocked the plasmatic imbibition by marginal resection around the venous island flap and delayed venous island flap and placing it onto the bare cartilage to exclude the effect of foreign body. We also examined the revasularization of the delay and non-delay venous island flap directly using microfil cast. As a result blocking of the plasmatic imbibition markedly decrease the survival of the flap but the survival of delay flap is about five times that of non delay flap. Revascularization was minimal at 1 week postoperative day. It is inferred that plasmatic imbibition is more important than revascularization.

RECONSTRUCTION OF FINGER DEFECTS WITH PEDICLED VENOUS ISLAND FLAP

Reconstruction of a injured digit needs good aesthetic result as well as functional recovery. Since Honda deported the first clinical application in 1984, the venous flap has been used increasingly for skin and soft tissue defects of the fingers and hands. From november 1992 to december 1995, 12 single-pedicled venous island flaps from hand dorsum were used for coverage of soft tissue defects of fingers over exposed bone, tendon, or joint. The pedicle of the flap included one superfitial dorsal vein of hand and its perivenous areolar tissue. Eight of twelve flaps survived completely and four necrosed partially possibly due to excessively long pedicle and poor perivenous areolar tissue. All donor sites were closed directly. Most patients were satisfied with postoperative result cosmetically and functionally. This method has several advantages : easy versatility and operability with superficial location of numerous dorsal vein, making good contour owing to proper thickness of flap, minimal donor site morbidity, and short operation time. We consider that the pedicled venous island flap is another reliable and useful method for reconstruction or finger defects as long as the pedicle length is not long and the perivenous areolar tissue is enough.