Effect of the CO2 milliwatt laser on neuroma formation in rats.

Background and Objective: The purpose of this study was to determine whether the milliwatt laser can suppress neuroma formation at the end of a divided nerve.
Study Design/materials and Methods: The peripheral nerves of eight rats were transected with microscissors and the cross-sectional area of their proximal ends was irradiated using the CO2 milliwatt laser. The power ranges used were similar to those applied to weld neural tissue.
Results: None of the eight irradiated nerve ends formed a neuromatous bulb and only one of them regenerated into the surrounding tissues. Histologically, these nerve ends did not show the disorganized picture of classic neuromas. On morphometric measurements, they contained less connective tissue than the control nerve ends (P < 0.001) and their nerve fibers were larger in diameter (P < 0.001) and better myelinated (P < 0.001).
Conclusion: These findings in rats show that the CO2 milliwatt laser has the ability to suppress neuroma formation at the end of a divided nerve.