An alternative preparation of the acellular muscle graft for reconstruction of the injured nerve - morphological and morphometric analysis

The application of cutaneous nerve grafts is accompanied by some disadvanta ges, including insufficient graft material for the reconstruction of a larg e mixed nerve. Recently, evacuated muscle autografts have been suggested as possible alternatives to cutaneous nerve grafts. In:the present paper we h ave demonstrated a possible preparation of the evacuated muscle graft using an infiltration of Marcaine. The reinnervation of the distal stump of the rat median nerve was evaluated by morphological and morphometric analysis a fter application of the muscle acellular grafts prepared by three methods: an ordinary freeze-thawed muscle graft, a Marcaine evacuated muscle graft a nd a Marcaine treated graft with subsequent freezing and thawing. A compari son of the numbers and diameters of the myelinated axons in the distal nerv e stumps revealed very similar conditions for axon regrowth and maturation in Marcaine evacuated and freeze-thawed muscle grafts. The best results wit h myelinated axon numbers and spectrum of their calibres were obtained when the Marcaine treated graft was repeatedly frozen and thawed. The pre-treat ment of the muscle graft by Marcaine prevents it from shrinking and fragmen ting, the main disadvantage during freeze-thawing of fresh muscle. The pres ent results demonstrate that infiltration of striated muscles with a myotox ic compound, e.g. Marcaine, with subsequent freezing-thawing is the method of choice for the preparation of an acellular muscle graft used in peripher al nerve reconnection in the experimental model.