Quantitative and qualitative muscular changes after selective neurotomy

Disfigurement of body contour, caused by excessive muscular hypertrophy, ca n seldom be effectively and safely corrected by lipectomy, liposuction or c ombined partial myomectomy. This study was conducted to obtain basic knowle dge for the development of a safe and effective method of treating patients with excessive and unwelcome muscle hypertrophy. Accordingly, we developed a new experimental rat model, consisting of the peroneal nerve and its tar get muscles - the anterolateral crural muscle group. After severance of 1/4 , 1/2, and 1/1 of the peroneal nerve, functional parameters based on gross movement and electrophysiologic data were monitored. Changes in the externa l circumference and weight of the anterolateral crural muscle were document ed and compared with control sides. Histologic and histomorphometric parame ters of the muscle were also documented. Average takeoff latency in 1/4 and 1/2 neurotomy groups was increased to 13 0% and 154% of the control at 3 months, and 156% and 149% of control at 6 m onths, respectively. Similarly, average peak-to-peak compound action potent ials were 72% and 59% of the control at 3 months and 57% and 50% of control at 6 months. No definite gait disturbances were evident in the partial neu rotomy groups. Maximal circumferences of the anterolateral crural muscle group were signif icantly reduced to 86%, 71% and 66% of the control in the 1/4, 1/2 and 1/1 neurotomy groups at 3 months (p<0.001), and to 74%, 68% and 64% of the cont rol at 6 months, respectively (p<0.001). The corresponding weights were 76% , 62%, and 50% of the control sides at 3 months, and 70%, 56%, and 48% at 6 months in 1/4, 1/2 and 1/1 neurotomy groups. Histograms drawn showing the number of muscle fibers per mm(2) in cross-sec tions, showed a total number of 239 +/- 52 in the control group; the size o f muscle fibers was mainly medium to large. The more extensive the neurotom y, the greater the was the number of small angulated muscle fibers, up to a total of 1,564 +/- 211. Although more research work and clinical trials are required, we believe th at selective neurotomy has the potential of being an effective tool for red ucing muscle bulk, and avoiding apparent muscular dysfunction and complicat ions.