骶神经根对直肠肛门功能选择性支配的实验研究

Selective innervation of the rectum and anal sphincter by sacral roots: a canine electrostimulation study

目的 :研究骶神经根对直肠和肛门功能的选择性支配 ,为临床从骶神经根角度重建脊髓损伤 (SCI)后的排便功能障碍提供依据。 方法 :对 7只 SCI犬进行硬膜外 L7～ S3神经根电刺激 ,用二导程测压仪同时记录直肠和肛门的压力变化。 结果 :犬直肠的神经支配以 S2 为主 ,S1 ,S3次之 ;肛门的神经支配以 S3为主 ,S1 ,S2 次之。对直肠、肛门的支配效能 ,均存在着右侧神经根大于左侧的特点。 85 %以上的 L7神经根对直肠、肛门有支配作用。结论 :不同神经根对直肠、肛门的功能支配 ,既有侧重 ,又有交叉。临床上重建 SCI患者的排便功能时 ,可针对性的选择效能最强的神经根。

Objective: To investigate whether there is a dominant sacral root to the motive function of rectum and anal sphincter, and provide experimental basis for neural reconstruction of defaecation in spinal cord injured (SCI) patients. Methods: Seven spinal cord injured mongrel dogs were included in the study. After L 4 L 7 laminectomy, the bilateral L 7 S 3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Results: For rectal innervation, S 2 is the most dominant, S 1 and S 3 contribute to a smaller extent. For sphincter, S 3 is the most dominant, S 1 and S 2 contribute lesser but still significant extent. Above 85% L 7 roots provide some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provide more contribution than the left ones. Conclusion: The functional innervation to the rectum and anal sphincter have a minor dominance but a major overlapping among different sacral roots. Its potential significance in restoration of controlled defaecation in SCI patients is discussed.