Pudendal nerve stimulation for bowel dysfunction in complete cauda equina syndrome.

Abstract

Pudendal nerve stimulation (PNS) aims to maximize afferent or efferent stimulation from the sacral plexus. We hypothesized this may be a promising new treatment for patients with bowel dysfunction in complete cauda equina syndrome (CES). Thirteen patients with complete CES [8 constipation predominant (group 1) and 5 incontinence predominant (group 2)] had a 3-week trial of PNS. Patients who showed a 50% or more improvement in symptoms during the trial phase proceeded to permanent neurostimulator implantation. Five (63%) of the 8 patients in group 1 showed a 50% or more improvement in bowel symptoms during the trial phase and were permanently implanted. The mean Cleveland Clinic constipation score, sense of incomplete evacuation (%), and straining during defecation (%) improved from 17 ± 3.2 to 10 ± 4.5, 94 ± 18% to 30 ± 35%, and 81 ± 23% to 44 ± 38%, respectively. All 5 patients in group 2 showed a 50% or more reduction in incontinent episodes during the trial phase. The mean St Mark's score, ability to defer defecation, and the number of incontinent episodes per week improved from 18 ± 1.0 to 3.8 ± 2.5, 2.2 ± 1.8 to 11 ± 5.5 minutes, and 9.4 ± 10.7 to 0.4 ± 0.5 episodes, respectively, per week. During a median follow-up of 12 (10-22) months of permanent implantation, one patient lost efficacy at 6 months due to lead migration and another required removal and reimplantation of the neurostimulator due to wound infection. PNS is an effective treatment in the short term for bowel dysfunction in some patients with complete CES.