Thinning: The Difference between Free and Propeller Perforator Flaps

into a short “handle”. This was a full-thickness skin bridge at the pivot point where the proximal flap was rotated 180 degrees downward towards the recipient site. The bridge acted to offer cutaneous and subcutaneous continuity and maintained an intact subdermal plexus to serve as additional channel for venous drainage [2]. After the flap was transposed to the knee, a vein graft was utilised to connect the descending femoral circumflex vein to the great saphenous to further augment drainage [3]. The patient experienced no evidence of postoperative flap congestion despite being at higher risk due to his large flap and at two year follow-up, showed good mobility ranging between 0 and 120 degrees flexion in the knee. Anterolateral thigh flaps are well understood and the anatomy well delineated, offering a large expanse of skin commonly utilised as free flaps. The distally based variant, supplied by retrograde arterial flow, can be used for coverage of knee defects [1]. Robust retrograde flow was observed intraoperatively in our case, likely secondary to medial geniculate contribution. Our concern was with insufficient venous drainage risking flap congestion and subsequent development of marginal flap necrosis [3]. The case illustrates two techniques available to alleviate venous congestion with either the preservation of a dermal and subcutaneous bridge in our racket handle or the anterograde anastomosis of a distal vein to drain the main pedicle vein. Although both techniques have been employed in this case to optimise venous drainage, each strategy is probably sufficient by itself to enhance venous outflow as there will be situations when only one is feasible. A skin bridge is unadvised in obese patients, as the thickness of subcutaneous fat physically restricts the pivoting of the flap, greatly limiting its reach. Conversely, venous anastomosis may be impractical in cases where the great saphenous vein is thrombosed, inflamed, or previously harvested for coronary bypass surgery. Fig. 4. At two year follow-up the defect has been closed with little overlying tension and minimal scarring allowing for acceptable range of movement. Minor scar revision of the dog-ear over the pivot point of the flap had been done. Fig. 5. Diagram of the transposed anterolateral thigh flap after anastomosing the main pedicle vein with the great saphenous vein. Great saphenous vein