Nerve resuturation decreases autotomy in the rat

Effects of different kinds of nerve lesions on denervation-induced self-mutilation (autotomy) was studied in the rat. Four different types of lesion were used: nerve transection, nerve transection combined with ligation and extirpation of the distal part of the transected nerve, nerve resuturation with a microsurgical technique, and lidocaine treatment after transection but before and during nerve resuturation. To determine the degree of nerve regeneration, the extensor muscles of the ankle joint were prepared and weighed after the follow-up period. If the transected nerves were resutured the incidence and severity of autotomy decreased significantly when compared to the transection+ligation-treated rats. The pretreatment with lidocaine did not further decrease the autotomy behavior of the rats whose nerves were resutured. In those rats who performed autotomy the early onset of self-mutilation correlated positively with a moderate, but not high or low, degree of restoration of the muscle weight. The present results suggest that autotomy can be decreased with good surgical techniques after nerve resuturation.