Laser, fibrin glue, or suture repair of peripheral nerves: a comparative functional, histological, and morphometric study in the rat sciatic nerve

Object. This study was undertaken to evaluate CO2 laser-assisted nerve repa ir and compare it with nerve repair performed with fibrin glue or absorbabl e sutures. Methods. In eight rats, the sciatic nerve was sharply transected and approx imated using two 10-0 absorbable sutures and then fused by means of CO2 mil liwatt laser welding (power 100 mW, exposure time 1 second per pulse, spot size 320 mum), with the addition of a protein solder (bovine albumin), to r einforce the repair site. The control groups consisted of eight rats in whi ch the nerves were approximated with two 10-0 absorbable sutures and Subseq uently glued using a fibrin sealant (Tissucol), and eight rats in which the nerves were repaired using conventional microsurgical sutures (four to six 10-0 sutures in the perineurium or epineurium). Evaluation was performed 1 6 weeks postsurgery and included the toe-spreading test and light microscop y and morphometric assessment. The motor function of the nerves in all grou ps showed gradual improvement with time. At 16 weeks, the motor function wa s approximately 60% of the normal function, and there were no significant d ifferences among the groups. On histological studies, all nerves revealed v arious degrees of axonal regeneration, with myelinated fibers in the distal nerve segments. There were slight differences in favor of the group treate d with laser repair, in terms of wound healing at the repair site. In all g roups, the number of axons distal to the repair site was higher compared wi th those proximal, but the axon diameter was significantly less than that i n control nerves (p < 0.05). There were no significant differences in the n umber, density, or diameter of the axons in the proximal or distal nerve se gments among the three nerve repair groups (p < 0.05), although there was a trend toward more and thicker myelinated axons in the distal segments of t he laser-repaired nerves. Conclusions. It was found that CO2 laser-assisted nerve repair with solderi ng is at least equal to Fibrin glue and suture repair in effectiveness in a rodent model of sciatic nerve repair.