A new epineural nerve repair technique: Oblique nerve coaptation

Despite the existence of various nerve coaptation techniques, functional re sults of nerve repair are still inadequate. Potential benefits of developin g modified coaptation techniques cannot be disregarded. The authors report a new coaptation technique in which the nerves are cut in an oblique fashio n to increase the coaptational surface. The sciatic nerves of male Wistar a lbino rats were cut at an angle of 30 and 45 deg (experimental groups), and 90 deg (control group). The nerves were repaired with nine 10-0 epineural stitches. Functional and histological studies were performed at week 12 on 7 rats from the 30-deg group, 15 rats from the 45-deg group, and 7 rats fro m the 90-deg group. Mean sciatic function index values of walking track ana lysis were the following: 30-deg group, -42.4 +/- 15.4; 45-deg group, -44.7 +/- 17.9; and 90-deg group, -52.9 +/- 13.9 (p > 0.05). The mean values of myelinated axonal counts for the 30-deg, 45-deg, and 90-deg transection gro ups were 196.2 +/- 3.7, 196.1 +/- 3.7, and 176.1 +/- 5.6 respectively for p roximal nerve segments and 180.1 +/- 6.8, 178.2 +/- 3.8, and 114.1 +/- 17.3 respectively for distal samples. Both the 30-deg and 45-deg coaptational g roups had a significantly lower reduction of myelinated axonal counts at th e regeneration zone in comparison with the 90-deg group (p < 0.01). Mean my elinated axonal diameters in the proximal nerve segments were 8.2 +/- 2.6 m u m 8.4 +/- 3.1 mu m, and 8.1 +/- 3.2 mu m respectively, and were 7.1 +/- 3 .6 mu m, 6.9 +/- 3.4 mu m, and 6.7 +/- 3.4 mu m respectively in the distal nerve segments (p > 0.05). The oblique nerve coaptation technique may enhan ce nerve regeneration by enabling a larger sprouting and contact area for n erve fibers, but additional investigation by more experienced centers is ne eded before relying on the preliminary results of this simple modification.