The island hemisoleus flap on distal vascular pedicle: anatomical bases and clinical applications

The coverage of skin defects of the ankle and of the distal fourth of the leg remains a difficult problem despite progress in reconstructive surgery. The aim of our study was to establish an arterial map of the lateral head of the soleus muscle, to compare it with the existing data in order to investigate the possibility of raising a fibular artery-based pedicle island reverse flow flap. It has the theoretical advantage over its medial counterpart of sparing the main arterial axis of the leg and foot. The anatomical study was undertaken on 15 fresh cadavers, 8 left and 7 right randomly chosen lower extremities from different subjects. For each calf, the following measurements were obtained: fibular length from the fibular head to the tip of the lateral malleolus; length of the lateral head of the soleus from its most proximal insertion point on the fibula to the most proximal part of the ending of the muscle belly on the Achilles tendon; width of the lateral head of the soleus; distance between the origin of the fibular artery and the tip of the fibular head; number and height of the pedicles for the lateral soleus, taking as reference their origin from the fibular artery. The mean dimensions of the muscle belly of the lateral soleus were 218 mm in length (between 160 and 270) and 73 mm in width (58–95). In all the examined lower extremities, we found a main pedicle for the lateral soleus emerging from the fibular artery; and in all cases the blood supply of the proximal part of the muscle was of a segmental distribution by way of multiple branches originating from the fibular artery. Then the flaps were raised with a distal pivot point represented by the perforating branch of the fibular artery. In all the cases, the flap would have covered an ankle or a dorsal foot defect up to the metatarsal heads.