Medial Sural Perforator “Nerve through Flap”: Anatomical Study and Clinical Application

Abstract

Background: Nerve recovery after a complex trauma is affected by many factors and a poorly vascularized bed is often the cause of failure and perineural scar. Many techniques have been devised to avoid this problem and the possibility to transfer a nerve with a surrounding viable sliding tissue could help in this purpose; Methods: We performed an anatomic study on 8 injected specimens to investigate the possibility to raise a medial sural artery perforator (MSAP) flap including the sural nerve within its vascularized sheath; Results: In anatomic specimens, a visible direct nerve vascularization was present in 57% of legs (8 out of 14). In 43% a vascular network was visible in the fascia layer. There were no vascular anomalies. In one patient the MSAP flap was raised including the sural nerve with its proximal tibial and peroneal components within the deep sheath. The tibial and peroneal component of the sural nerve were anastomized independently with the common digital nerve of 4th and 5th fingers and with the collateral nerve for the ulnar aspect of the 5th. After 9 months, the patient showed an improving nerve function both clinically and electromyographically without any problem due to nerve adherence; Conclusions: Given the still debated advantage of a vascularized nerve graft versus a non-vascularized one, this flap could be useful in those cases of composite wounds with nerve lesions acting as a “nerve through flap”, in order to reduce nerve adherence with a viable surrounding gliding tissue.