|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1997 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1996 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Purpose : We have investigated the proper method of magnetic stimulation of the spinal nerve to evoke a twitch contraction of the external anal sphincter (EAS) in rabbit and children, and its clinical significance in the field of pediatric surgery was investigated.
Method : The electromyogram (EMG) of the EAS was recorded at the anal verge using EMG analyzer (MEM 4204, Nihon Kohden). Magnetic stimulator (SMN-100, Nihon Kohden) and figure eight coil (YM-111B,Nihon Kohden) were used.
Result : In animal studies using l5 white rabbits, magnetic stimulation of the spinal nerve was quite effective to induce a contraction of EAS.A reproducible monophasic EMG was recorded in response to a magnetic stimulation of thoracic and lumbar spine, while multiphasic EMG was induced to stimulation of the sacral segment, suggesting a diversity of the pudendal nerve at the level of the cauda equina. In l5 healthy children, a twitch contraction of EAS was evoked only to stimulation at levels of lumbar and sac
ral segment and lumbar spinal stimulation was suitable for a measurement of EMG latency. Magnetic stimulation was useful to induce a twitch contraction of the EAS in 4 pre-operative and l2 post-operative patients with anorectal malformation. Site and degree of pudendal nerve disturbance in each patient could be estimated properly in combination with the present result using magnetic spinal stimulation and previous results using the transanal electrical stimulation of the pudendal nerve to induce EAS contraction.
As the results of on-going research projects from l994, a close correlation of post-operative bowel dysfunction and pudendal nerve dysfunction could be demonstrated in patients with Hirschsprung's disease and anorectal malformation. Furthermore, in long-standing icteric post-operative patients with biliary atresia, the presence of somatosensory evoked potential abnormality not due to vitamin E deficiency was also revealed, which could be improved by the liver transplantation.
Conclusion : Magnetic spinal stimulation was a non-invasive method to evoke EAS contraction in children and this technique was useful in an evaluation of EAS function in the normal and the pediatric patients. Less