Fascicular turnover flap for nerve gaps

It is well known that free vascularised nerve grafts have a potential for rapid axonal sprouting. However, they are not very popular as the surgical techniques are complicated. With the recent development of supramicrosurgical techniques and microanatomy of nerve trunks, a new method, 'fascicular turnover method', using vascularised fascicular flap was used for repairing nerve gaps. METHODSAND RESULTS: Arterial embalming method, using rat sciatic nerves, was employed to observe fascicular micro-vascularisation. Rich vascular network systems were observed within and outside the rat island nerve flaps. Four cases with digital and facial nerves gaps were repaired with fascicular turnover flap without a nerve graft. Three patients had digital nerve gaps (10-20mm in length) and one had a 3-cm facial nerve gap. The results of sensory recovery of digital nerve gap were 3.22-3.66 (Semmes-Weinstein values) and 6-12mm (moving two-point discriminations) at 6 and -16 months after surgery, respectively.

The advantages of this method are: retention of the normal donor nerve, a shorter operation time and repair of the digital nerve gaps under local anaesthesia. Fascicular flap is a vascularised nerve flap with fast and accurate nerve sprouting in comparison to a non-vascularised graft. Excellent nerve regeneration can be expected even in cases with longer nerve gap and scarred recipient bed. It is a simple and quick surgery compared to free vascularised nerve flaps. In addition, there is no functional loss because of the sacrificed fascicle in the operated area. The only disadvantage is the need to employ superficial palmar branch of radial artery (SPRA)-microsurgical techniques using a 50-micron needle.