An Experimental Model of Chronic Nerve Compression in the Rat

Cheon, Sang Jin; Kim, Young Ho; Lee, Dong Ho; Huh, Gi Yeong; Kim, Hui Taek; Yoo, Chong Il

Abstract

PURPOSE
The aim of this study was to develop a model for chronic nerve compression in a rat and a model reproducing a normal anatomical narrow portion that lies in the course of the peripheral nerve. MATERIALS AND METHODS: Male Sprague-Dawley rats were used. A 5 mm tendinous band was made from the patellar tendon harvested from each rat and placed around the sciatic nerve. In order to determine the degree of compression, a series of internal diameters of the band (0.2 mm smaller than (group I), same as (group II), and 0.2 mm (group III), 0.4 mm (group IV) and 0.6 mm greater (group V) than the diameter of sciatic nerve) were used. The rats were evaluated at 1, 2, 3, 4, and 6 months after banding using an electroneurophysiologic study, a pathohistologic study, and the morphometric nerve fiber analysis. RESULTS: In groups III and IV the morphometric findings showed statistically significant compressive changes in the periphery after 3 and 4 months, respectively and revealed significant changes in both the periphery and central portion at 6 months (p<0.05). In group V, the measurements and histologic findings were almost identical to the control group at 6 and 10 months. The nerve electrophysiologic study showed significant compressive changes at 6 months in groups III and IV (p<0.05). In the group V, the measurements were similar to those of the normal control. CONCLUSION: Groups III and IV appear to be a reliably reproducible chronic nerve compression model while excluding the possibility of foreign body reactions. In addition, group V appears to be a reliable model of a normal anatomical narrow portion that lies in the course of the peripheral nerve.