Review of Sacral Neuromodulation for Management of Constipation

Background. Sacral neuromodulation (SN) is an emerging treatment for constipation. This review evaluates the mechanism of action, techniques, efficacy, and adverse effects of SN in the management of constipation. Methods. Electronic searches for studies describing the use of SN were performed in PubMed, MEDLINE and Embase. Abstracts were reviewed and full text copies of all relevant articles obtained. Results. Fifty-nine results were obtained on the initial searches. Ten studies discussed the results of SN in patients with constipation. A total of 225 temporary neuromodulations and 125 permanent implants were performed. Bowel diaries showed improvement in assessment criteria in more than 50% of patients on temporary neuromodulation and the results were maintained in approximately 90% of patients who underwent permanent implantation over medium to long-term follow-up. The rate of adverse effects was high, but the majority of them were related to electrode position. Improvements in transit studies and anorectal physiology after neuromodulation were noted in some studies. The recognized limitations included a lack of randomized studies and an inability to perform meta-analysis. Conclusion. Sacral neuromodulation may be an effective treatment in selected patients with constipation and should be a part of the management repertoire. Improvement in defecatory frequency with temporary wire placement is a good predictor of subsequent response following permanent implant. Further research into predictive factors for success would improve patient selection.