Electrophysiological and histological studies of laser and suture anastomosis in rat sciatic nerve

In order to compare the effects of the two repair techniques, a controlled study was devised in which the right sciatic nerve of Sprague-Dawley rats was surgically cut and reanastomosed by means of either four epineurial sutures or two epineurial sutures and CO₂ laser welds. After a mean of 11 months, both sciatic nerves were excised. The conduction velocities recorded for suture-and laser-assist-repaired nerves were not found to be significantly different. However, laser-repaired nerves exhibited lower conduction failure rates and lower stimulation thresholds than nerves with conventional suture repair. No apparent difference in the diameter of myelinated fibers distal to the anastomosis in either of the two repair categories was observed. Sutured nerves exhibited greater branching of myelinated axons proximal to the anastomosis and at the same time permitted fewer axons through the anastomosis as compared to laser-repaired nerves. It is suggested that this could explained the greater incidence of neuroma formation in sutured nerves as well as the diminished conduction.