Effect of the neodymium:yttrium aluminum garnet laser on postoperative neuroma formation after neurectomy in rats.

The effect of neodymium:yttrium aluminum garnet (Nd:YAG) laser-performed neurectomy was compared with conventional scalpel-performed neurectomy, using the rat sciatic nerve model. Sixteen male Sprague-Dawley rats underwent unilateral transection of the sciatic nerve by 1 of 3 methods. The sciatic nerve of rats under general anesthesia was transected by use of a steel scalpel blade (group 1, n = 5); a contact Nd:YAG laser at 6W of power (group 2, n = 6); or an Nd:YAG laser at 12 W of power (group 3, n = 5). Thirty days after surgery, all rats were euthanatized and the nerves were harvested, imbedded in paraffin, fixed, and sectioned for light microscopy. Neurodegenerative changes and perineurial cell proliferation were least severe in the nerves transected by use of a steel scalpel (group 1), and were most severe in nerves transected by use of laser at 6 W of power (group 2). There was a significant difference in prevalence of perineurial proliferation between the scalpel and laser neurectomy groups (P = 0.029). There was no significant difference in prevalence of neuroma formation or neurodegeneration between the laser and scalpel neurectomy groups, although neuromas were found in 3 rats (2 from group 2 and 1 from group 3). Within the limits of this study, we found that the Nd:YAG laser was less successful than sharp division, using a scalpel, in preventing neuroma formation after nerve transection.