Intraoperative Tips and Tricks for Successful Sacral Neuromodulation

Abstract

Sacral neuromodulation (SNM) is an effective, minimally invasive treatment for refractory overactive bladder, non-obstructive urinary retention, and fecal incontinence. Although the treatment is 80% successful, optimal outcomes over time are achieved only by applying precise surgical technique. In this review, we will present the surgical technique for optimal SNM documented in the literature, as well as provide tips for ideal placement based on the authors’ experience. The technique of SNM placement has greatly evolved over the last 10 years with the routine use of fluoroscopy as well as the introduction of the curved, tined lead. With these developments, surgeons have begun to pay more attention to motor thresholds needed to achieve anal bellows and toe flexion responses during staged lead implants. By achieving lower motor thresholds, ideally less than 2 mA, patients have a lower risk of future lead revision and may benefit from longer battery life and greater reprogramming options. Ideal lead placement for SNM includes superior medial entry into the S3 foramen, with a lateral curvature of the distal lead to follow the S3 nerve root. Specific fluoroscopic findings, along with low motor thresholds for anal bellows and toe flexion, confirm ideal lead placement. Surgeons should make every effort to achieve the ideal lead. In patients with inadequate response to therapy, the lead can be checked on x-ray for ideal characteristics, and a revision should be considered if there is room for improvement.