Regeneration of peripheral nerves following Nd-YAG laser and scalpel transection—Experimental observations

Regeneration of 70 rat sciatic nerves was investigated following transection by a 1.06 μm neodymium-doped yttrium aluminium garnet (Nd-YAG) laser and by a conventional scalpel. Twenty-three amputation stumps after each technique were reexposed at different intervals between 3 and 240 days. In an second series 12 nerve trunks each were taken out following initial epineural suture repair after survival periods between 30 and 90 days. Light and electron microscopic findings were evaluated. Amputation neuromas could be observed in 16% of laser and 83% of scalpel cases. Laser neuromas were small and without adherence to surrounding tissue structures. Following end to end coaptation the repair site was crossed by sprouting axons in 92% of laser cases and in all nerves after scalpel division. Laser transection and suture repair resulted in optimal coaptation without fusiform thickening by proliferation of epineural fibroblastic tissue. Scar reactions with compression of the microfascicular pattern was present in 8% of laser and 75% of scalpel cases.