An experiment study of the effect of high frequency electrotome on preventing the formation of painful neuroma

Abstract

Objective To investigate the feasibility and practicability of high frequency electrotome cutting and (or) coagulation of nerve stumps in preventing painful neuroma formation. Methods Fifty-six 3-month-old Sprague-Dawley rats were randomly divided into four groups with 14 rats each. Depending on group assignment, the sciatic nerve was cut by a blade, by electric cutting with a high frequency electrotome, by electric cutting and coagulation with the electrotome, by a blade and electric coagulation with the electrotome. Postoperative observation and evaluations included the incidence of autotomy, the diameter of the nerve stump, nerve fiber regeneration and orientation at the nerve stump, and immunohistochemical staining of nerve growth factor (NGF) expression at the sciatic nerve stump. Results The blade and electric coagulation group had the lowest autotomy level, the latest autotomy onset, and the lowest incidence of severe autotomy. The nerve stump did not show obvious enlargement, neither was it adhered to the surrounding tissue. On the contrary the electric cutting group had the highest autotomy level, the shortest average onset time of autotomy and the highest incidence of severe autotomy. There was obvious neuroma formation at the nerve stump which was tightly adhered to the surrounding tissue. The differences between these two groups were significant (P<0.05). Immunohistochemical staining demonstrated NGF expression in the nerve stumps of rats in all 4 groups. The expression level was the lowest in the blade and electric coagulation group and highest in the electric cutting group. Conclusion Cutting nerve with a sharp blade and coagulating it with a high frequency electrotome is an effective method to prevent the formation of painful neuroma. This method is not only simple but also cost efficient. Key words: Neuroma; Electrocoagulation; Stump pain; Animal experimentation