A novel technique for peripheral nerve repair.

Objective: To evaluate a novel technique for the repair of neural deficits using a single fascicle to bridge an injury in the rat sciatic nerve.

Study Design: Twenty-four male Lewis rats were divided into four groups as follows: group 1 (control group), 1.5-cm deficit without repair; group 2, conventional epineural repair with autografts (100% diameter); group 3, nerve repair with large single autograft fascicle (50% diameter); and group 4, nerve repair with small single autograft fascicle (25% diameter).

Methods: Nerve regeneration was evaluated at 3, 6, and 12 weeks by somatosensory evoked potential (SSEP) evaluation and standardized pin-prick and toe-spread tests. Nerve samples were harvested at 12 weeks and stained with toluidine blue to assess the total number of myelinated axons, axon area, and myelin sheath thickness.

Results: In group I, the pin-prick and toe-spread tests showed no response at 3, 6, and 12 weeks. Rats in groups 3 and 4 demonstrated significantly better pin-prick test results and a trend toward better toe-spread test responses compared with conventional-repair animals. The SSEP evaluations displayed nondiagnostic waves in rats in group 1 rats. There was no evidence that the other surgery groups differed significantly in median SSEP latencies. Histological evaluation revealed fibrosis in rats in group 1 rats and a significantly higher median number of axons and myelin thickness in the small single fascicle (1296 axons and 4.22 microm, respectively) and large fascicle (2682 axons and 4.62 microm, respectively) groups compared with the conventional autograft group (630 axons and 2.93 microm, respectively). The small fascicle group had a significantly greater mean axon area (58.59 micro m2) than the large fascicle (29.66 micro m2) and conventional autograft (25.35 micro m2) groups.

Conclusions: Peripheral nerve repair using a single fascicle graft resulted in better functional recovery and morphometric outcome without a significant difference in electrophysiological status compared with conventional nerve repair. This technique may provide expanded sources of nerve autografts and alleviate the morbidity of harvesting peripheral nerves from multiple sites for individuals with extensive peripheral nerve injuries.