Effectiveness of Sacral Neuromodulation in Low Anterior Resection Syndrome

Prospective Randomized Cross-over Trial to Assess the Effectiveness of Sacral Neuromodulation in Low Anterior Resection Syndrome. SANLARS Trial (SAcral Neuromodulation for Low Anterior Resection Syndrome)

Low anterior resection syndrome (LARS) is a complex disorder suffered by patients who undergo rectal resection mainly due to rectal cancer. It is characterized by fecal incontinence, fragmented defecation, constipation, defecatory urgency among others, which induce an impairment in quality of life.

LARS treatment armamentarium is scarce and with no long-term relief, being a difficult challenge for surgeons. There is evidence showing that sacral neuromodulation (SNM) improves patients' symptoms and quality of life. However, no prospective randomized studies have supported this improvement.

This is a prospective randomized cross-over study which evaluates the effectiveness of SNM in LARS, specifically analyzing intestinal, urinary, sexual symptoms as well as quality of life.

Inclusion Criteria:

• Patients who have had an anterior rectal resection with sphincter preservation by any approach, with or without preoperative radiotherapy.
• Patients with symptomatology of major anterior resection syndrome (>29 points on LARS score) including fecal incontinence, defecatory urgency, fecal fragmentation.
• Period greater than one year since the last definitive surgery (rectal resection or ileostomy closure).
• Period longer than one year in cases in which any other type of therapy has been performed for the anterior resection syndrome (for example: biofeedback, posterior tibial stimulation, physiotherapy, etc).

Exclusion Criteria:

• Patients who refuse to sign informed consent or are unable to understand the study.
• Patients with progression of the oncological disease.
• Patients in initial stage IV (metastatic).
• Patients with inflammatory bowel disease.
• Patients with known irritable bowel prior to rectal surgery.
• Patients who have undergone resection of other intestinal segments.
• Patients with systemic neurological diseases with involvement of long pathways or spinal cord injury.