Effect of sacral anterior root stimulator on bowel dysfunction in patients with spinal cord injury

Bowel dysfunction is a problem in patients with spinal cord injury. The sacral anterior root stimulator has been used for neurogenic bladder and has been claimed to be useful for neurogenic bowel. The purposes of this study were to analyze the clinical response of bowel function to the sacral anterior root stimulator and to evaluate physiologic factors that could determine its efficacy.

Eighteen consecutive patients with spinal cord injury and an implanted sacral anterior root stimulator were evaluated. Clinical assessment, colonic transit time, and anorectal manometry were performed. Patients were evaluated before implantation of the sacral anterior root stimulator and clinically reevaluated after 12 months.

Fewer patients required laxatives after implantation of the sacral anterior root stimulator. The mean number of methods used to evacuate was reduced from 2.1 to 1.5 (P < 0.05). Bowel movement frequency was higher (P < 0.05). Time devoted to defecation was reduced, although no statistical significance was achieved. Fecal incontinence did not change, but constipation was reduced (P < 0.05). Most patients reported being more satisfied with bowel function after implantation of the sacral anterior root stimulator. No correlation was found between objective and subjective responses to the sacral anterior root stimulator and manometric or colonic transit times before implantation.

The sacral anterior root stimulator improves bowel function, and patient satisfaction with this treatment is high. Further studies are needed to evaluate the characteristics of stimulation parameters to achieve better results.