A comparison of flap vascular anatomy in three rhytidectomy techniques

The purpose of this study was to examine differences in blood supply to facial flaps created by three rhyditectomy techniques. The techniques chosen for comparison included a two-layer technique, consisting of separate subcutaneous and extended submuscular aponeurotic system (SMAS) dissections, the Composite dissections as described by Hamra, and a subperiosteal dissection. Six cadavers were injected with lead oxide before dissection, and eight were injected after dissection. After allowing the lead oxide to set, the soil tissues were removed from the face. Vascular patterns of the face were interpreted from x-rays taken of the specimens. Results of the injections performed before dissection confirmed contributions of previously described arteries, including the transverse facial, facial, intra-orbital and terminal branches of the ophthalmic. In addition, there are numerous branches that connect these vessels to each other. The most consistent of these include the masseteric, jugal, submental, labial, angular and nasal arteries. The patterns of communications between these vessels allow for the visualization of three vertically oriented vascular zones, each connected to the next by choke zones where anastomoses occur. Dissections performed before injection reveal increased filling of the vessels through more of the flap on the Composite side when compared with the two-layered dissection, absence of vessels in the SMAS, and filling across all three zones on the subperiosteal side. We conclude that there are vascular regions in the face connected by anastomotic choke zones. Separate subcutaneous and sub-SMAS dissections interrupt the vascular connection between zones. Arterial continuity is better-maintained in the Composite lift and is literally undisturbed in the subperiosteal lift. These findings may help to explain why extreme tension applied to the Composite flap during closure is so well-tolerated and wiry extended subcutaneous dissection places the skin at risk for ischemic necrosis. Finally, the SMAS may contain a separate vascular supply, but this supply is probably tenuous and easily compromised after extensive dissection.