Brief Reports
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 21, 2005; 11(11): 1715-1718
Published online Mar 21, 2005. doi: 10.3748/wjg.v11.i11.1715
Sacral anterior root stimulated defecation in spinal cord injuries: An experimental study in canine model
Shi-Min Chang, Guang-Rong Yu, Ying-Min Diao, Meng-Jie Zhang, Shi-Bo Wang, Chun-Lin Hou
Shi-Min Chang, Guang-Rong Yu, Department of Orthopedic Surgery, Tongji Hospital, Tongji University, Shanghai 200065, China
Ying-Min Diao, Meng-Jie Zhang, School of Life Science and Biomedical Engineering, Tongji University, Shanghai 200092, China
Shi-Bo Wang, Chun-Lin Hou, Department of Orthopedic Surgery, Changzheng Hospital, Shanghai 200003, China
Author contributions: All authors contributed equally to the work.
Supported by the National Science Fundation of China, No. 30440058
Correspondence to: Shi-Min Chang, M.D., Ph.D, Department of Orthopedic Surgery, Tongji Hospital, Tongji University, Shanghai 200065, China. shiminchang@yahoo.com.cn
Telephone: +86-21-56051080-1090 Fax: +86-21-56050502
Received: April 7, 2004
Revised: April 8, 2004
Accepted: May 24, 2004
Published online: March 21, 2005
Abstract

AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord injuries.

METHODS: Eleven spinal cord injured mongrel dogs were included in the study. After L4-L7 laminectomy, the bilateral L7-S3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Four animals were implanted electrodes on bilateral S2 roots.

RESULTS: For rectal motorial innervation, S2 was the most dominant (mean 15.2 kPa, 37.7% of total pressure), S1 (11.3 kPa, 27.6%) and S3 (10.9 kPa, 26.7%) contributed to a smaller part. For external anal sphincter, S3 (mean 17.2 kPa, 33.7%) was the most dominant, S2 (16.2 kPa, 31.6%) and S1 (14.3 kPa, 27.9%) contributed to a lesser but still a significant part. Above 85% L7 roots provided some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provided more contribution than the left roots. Postoperatively, the 4 dogs had electrically stimulated defecation and micturition under the control of the neuroprosthetic device.

CONCLUSION: S2 root is the most dominant contributor to rectal pressure in dogs. Stimulation of bilateral S2 with implanted electrodes contributes to good micturition and defecation in dogs.

Keywords: Spinal cord injury; Defecation; Sacral root; Electrical Stimulation