DIGITAL RECONSTRUCTION USING THE DISTALLY BASED OSTEOFASCIOCUTANEOUS RADIAL FOREARM FLAP

The Chinese forearm flap is a versatile flap in hand reconstruction. Five cases are reported. The mechanism and reliability of retrograde venous return is discussed. The radial forearm flap can be elevated as a distally-based island flap in hand reconstruction (Biemer, 1983). The anatomy of the flap is well documented (Cormack, 1986; Lamberty, 1982; Soutar, 1984; Timmons, 1986). With a proximally divided pedicle, arterial input is from the distal radial artery, fed via the palmar arches from the ulnar artery. Venous drainage is through the venae comitantes by retrograde flow (Biemer, 1983). The venae comitantes are valved every 1 to 3 ems and communicate by cross connections in a ladder-like fashion (Figure 1). They constitute the deep system of veins which comp-lement and communicate with the superficial system (cephalic and basilic veins) via the lateral intermuscular septum. Fig. 1 Cross-connections between venae comitantes. Recently it has been suggested that distally-based forearm flaps, with retrograde flow, may become venously embarrassed (Matev, 1985). In our experience, this has not been so. Five case reports are presented and existing knowledge on the pathophysiology of reverse flow is discussed. Case Reports Case 1. A 33-year-old right-handed male agricultural worker avulsed his left thumb in a combine harvester in March, 1983. An 0.5 cm length of the proximal phalanx remained intact, but both flexor tendons were avulsed at the musculotendinous junctions. He was treated else-where by simple closure and split skin grafting. In October 1983, a distally-based left osteofasciocutaneous forearm flap was used for thumb reconstruction. Drainage was retrograde via the venae comitantes. Postoperatively there was no evidence of venous insufficiency