Bilateral sacral spinal nerve stimulation for fecal incontinence after low anterior rectum resection

Background and aims: The somatomotor innervation pattern has been shown to differ in patients undergoing percutaneous nerve evaluation for sacral nerve stimulation. In some patients bilateral stimulation might improve clinical outcome; however, only single-channel pulse generators have until now been available. We report a patient with fecal incontinence after surgery for rectal carcinoma in whom a dual-channel, individually programmable, pulse generator permitted implantation of neurostimulation electrodes bilaterally. Patients and methods: Intractable fecal incontinence developed in a 48-year-old man who underwent low anterior rectum resection, owing mainly to reduced internal anal sphincter function. The morphology of the anal sphincter was without defect. Based on the findings of unilateral and bilateral temporary sacral nerve stimulation the patient underwent placement of foramen electrodes on S4 bilaterally. Both electrodes were connected to a dual-channel impulse generator for permanent low-frequency stimulation. Results: The percentage of incontinent bowel movements decreased during unilateral test stimulation from 37% to 11%, during bilateral test stimulation to 4%, and with chronic bilateral stimulation to 0%. The Wexner continence score improved from 17 preoperatively to 2, and quality of life (ASCRS score) was notably enhanced. Anorectal manometry revealed improved striated anal sphincter function; the internal anal sphincter remained unaffected. Conclusion: Sacral nerve stimulation can effectively treat incontinence after rectal resection, and bilateral stimulation can improve the therapeutic effect.