Magnetic resonance angiography to evaluate septocutaneous perforators in free fibula flap transfer

Background: In harvesting free fibula composite flaps, preoperative knowledge of the lower limb vascular anatomy is essential to prevent ischaemic complications or flap failure. Magnetic resonance angiography (MRA) allows imaging of the septocutaneous perforators (≤1-2 mm diameter) of the peroneal artery used in the free fibula flap. Methods: We investigated seven patients undergoing the free fibula flap preoperatively with high-resolution MRA images to study the following: 1) tibio-peroneal anatomy, 2) peripheral artery disease, 3) the positions of the perforator vessels on the peroneal artery and their course in the posterolateral intermuscular septum and 4) the cutaneous distribution of the perforators, and to compare them to surgical findings. Results: MRA demonstrated tibio-peroneal anatomy in sufficient detail to exclude anatomic variants and significant peripheral vascular disease, detected septocutaneous perforators arising from the peroneal artery coursing in the posterolateral intermuscular septum and determined the skin terminus of the septocutaneous perforators. All septocutaneous perforators found during surgery were detected prospectively on high-resolution MRA. Conclusion: Lower leg vascular anatomy assessment with high-resolution MRA determined the location of the septocutaneous perforators of the peroneal artery preoperatively with accuracy and precision. This anatomical knowledge provides for a safer procedure and the opportunity to plan surgical details preoperatively.