Effects of highly selective sympathectomy on neurogenic bowel dysfunction in spinal cord injury rats

Peipei Xu,Degang Yang,Yang Xie,Liangjie Du,Xin Zhang,Yan Yu,Yixin Chen,Zitong Liu,Mingliang Yang,Shuang Guo,Changbin Liu,Huiming Gong

doi:10.1038/s41598-021-95158-5

Abstract

Neurogenic bowel dysfunction, including hyperreflexic and areflexic bowel, is a common complication in patients with spinal cord injury (SCI). We hypothesized that removing part of the colonic sympathetic innervation can alleviate the hyperreflexic bowel, and investigated the effect of sympathectomy on the hyperreflexic bowel of SCI rats. The peri-arterial sympathectomy of the inferior mesenteric artery (PSIMA) was performed in T8 SCI rats. The defecation habits of rats, the water content of fresh faeces, the intestinal transmission function, the defecation pressure of the distal colon, and the down-regulation of Alpha-2 adrenergic receptors in colon secondary to PSIMA were evaluated. The incidence of typical hyperreflexic bowel was 95% in SCI rats. Compared to SCI control rats, PSIMA increased the faecal water content of SCI rats by 5–13% (P < 0.05), the emptying rate of the faeces in colon within 24 h by 14–40% (P < 0.05), and the defecation pressure of colon by 10–11 mmHg (P < 0.05). These effects lasted for at least 12 weeks after PSIMA. Immunofluorescence label showed the secondary down-regulation of Alpha-2 adrenergic receptors after PSIMA occurred mainly in rats’ distal colon. PSIMA mainly removes the sympathetic innervation of the distal colon, and can relieve the hyperreflexic bowel in rats with SCI. The possible mechanism is to reduce the inhibitory effect of sympathetic activity, and enhance the regulatory effect of parasympathetic activity on the colon. This procedure could potentially be used for hyperreflexic bowel in patients with SCI.

Highlights

Neurogenic bowel dysfunction, including hyperreflexic and areflexic bowel, is a common complication in patients with spinal cord injury (SCI)
The periarterial sympathectomy of the inferior mesenteric artery (PSIMA) (Fig. 1A), which only cuts off sympathetic postganglionic neurons, has potential clinical value and feasibility in the treatment of Neurogenic bowel dysfunction (NBD) in patients with SCI
We evaluated the effect of peri-arterial sympathectomy of the inferior mesenteric artery (PSIMA) on the normal rats and SCI rats from the aspects of defecation rate, the number of faecal particles excreted during an observation period, and Bristol Stool Scale

Summary

Introduction

Neurogenic bowel dysfunction, including hyperreflexic and areflexic bowel, is a common complication in patients with spinal cord injury (SCI). PSIMA mainly removes the sympathetic innervation of the distal colon, and can relieve the hyperreflexic bowel in rats with SCI. The possible mechanism is to reduce the inhibitory effect of sympathetic activity, and enhance the regulatory effect of parasympathetic activity on the colon This procedure could potentially be used for hyperreflexic bowel in patients with SCI. We hypothesize that for patients with the hyperreflexic bowel secondary to cervical and thoracic SCI, partial removal of the sympathetic innervation of the left colon may decrease the sympathetic effects, relatively enhance the regulation of parasympathetic nerve to the colon, and help to alleviate the NBD after SCI. The periarterial sympathectomy of the inferior mesenteric artery (PSIMA) (Fig. 1A), which only cuts off sympathetic postganglionic neurons, has potential clinical value and feasibility in the treatment of NBD in patients with SCI

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