An assessment of the effects of internal neurolysis on a chronically compressed rat sciatic nerve.

Chronically compressed nerves were treated with three surgical modalities. Simple decompression was compared to internal neurolysis with and without the addition of extrafascicular steroid. Electrophysiologic, histologic, and morphometric assessments were performed. Compressed control nerves demonstrated changes compatible with severe nerve compression (Wallerian degeneration). With simple decompression, improvement in histologic and electrophysiologic parameters occurred. When internal neurolysis was added to the decompression, further improvement in histologic and electrophysiologic parameters was noted. There was no added improvement with the addition of steroids.