Potassium titanyl phosphate laser welding following complete nerve transection

Objectives/Hypothesis: Cranial nerve transection during head and neck surgery is conventionally repaired by microsuture reanastomosis. Laser nerve welding (LNW), using CO₂ laser to spot-weld the epineurium of transected nerve endings, has been shown in animal models to be a novel alternative to microsuture repair. This method avoids needle/suture material and minimizes instrumentation of the nerve. We hypothesized that potassium titanyl phosphate (KTP) laser would be superior to CO₂ laser in repairing transected nerves. Using a rat posterior tibial nerve injury model, we compared CO₂ laser, KTP laser, and microsuture reanastomosis. Study Design: Animal study. Methods: Animals underwent unilateral posterior tibial nerve transection. The injury was repaired by microsuture repair (n = 15), CO₂ laser repair (n = 15), or KTP laser repair (n = 15). Weekly walking tracks were performed to measure functional recovery. Nerve segments were harvested for axon counting. Results: At 6 weeks, the KTP LNW had the best functional recovery (92.4 ± 8.6%) compared to microsuture repair (84.5 ± 10.2%, difference 7.9%, 95% confidence interval [CI]: 0.84%-14.96%). CO₂ laser repair had a functional recovery of 86.8 ± 11.2%. KTP LNW had better axon recovery compared to transection/repair (difference 530.7 axons, 95% CI: 329.9-731.5). Operative time for the microsuture repair was 18.2 ± 6.8 minutes, compared to 5.8 ± 3.7 minutes for the LNW groups (difference 12.4 minutes, 95% CI: 8.6-16.2 minutes). Conclusions: KTP, CO₂, and microsuture repair all showed good functional recovery following complete transection of the posterior tibial nerve. Following complete nerve transection during head and neck surgery, KTP LNW may be a novel alternative to microsuture repair. Level of Evidence: NA Laryngoscope, 127:1525–1530, 2017.