Sacral Nerve Stimulation in Treating Low Anterior Resection Syndrome or Fecal Incontinence in Patients With Locally Advanced Rectal Cancer or Other Pelvic Cancer, the RESTORE Study

PRIMARY OBJECTIVES: I. To investigate the efficacy of sacral nerve stimulator placement in patients with fecal incontinence (FI) or low anterior resection syndrome (LARS) who have previously undergone chemoradiation treatment (XRT) and/or a restorative partial or complete proctectomy with colorectal or coloanal anastomosis for cancer treatment as per standard of care (restorative surgery cohort). II. To evaluate the feasibility of sacral nerve stimulator placement in patients with fecal incontinence (FI) or other defecatory dysfunction who have received pelvic radiation treatment without undergoing rectal or other pelvic surgery as per standard of cancer care (radiation only cohort). SECONDARY OBJECTIVES: I. To evaluate the effectiveness of sacral nerve stimulation (SNS) as measured by validated questionnaires in patients with FI or LARS within both patient cohorts. II. To evaluate pelvic floor and sphincter physiology using anorectal manometry (ARM) before and after SNS in patients with FI or LARS within both patient cohorts. III. To assess potential impact of SNS on urinary incontinence measuring a post-void urinary bladder residual and validated urinary symptom questionnaires in both patient cohorts. IV. To assess efficacy of SNS on long-term bowel dysfunction at 1 and 3 years post battery implantation as measured by validated questionnaires for both patient cohorts. OUTLINE: Patients undergo scheduled, elective surgery for placement of the sacral nerve stimulator with external battery pack. After 2 weeks, patients undergo implantation of a subcutaneous internal battery or removal of the leads if the sacral nerve stimulator is working but does not improve symptoms. If the sacral nerve stimulator is not working, it is repositioned and patients return 2 weeks later for implantation of external battery or removal of leads. After completion of study, patients are followed up at 1 month, 1 year, and 3 years.