Does choice of anesthesia during stage 1 sacral neuromodulation testing influence outcomes?

Staged sacral neuromodulation (SNM) testing has been shown to have a high rate of progression to permanent implantation for the management of voiding dysfunction. Stage 1 lead placement (SNM-I) can be performed under monitored anesthesia care (MAC) or general anesthesia (GA). MAC allows for interpretation of sensory and motor responses to optimize lead placement while GA only permits for motor assessment. However, patient discomfort and movement can make lead placement challenging during MAC. Herein we evaluate whether the anesthesia type impacts the progression rate to permanent implantation (SNM-II).

A retrospective chart review was performed for patients who underwent SNM-I in the operating room for wet overactive bladder between 2005 and 2023. Patients were divided into two groups based on the type of anesthesia used, MAC or GA. Clinical variables and progression to SNM-II were compared between cohorts. Progression to SNM-II was based on ≥50% symptomatic improvement during a 1-2 week trial period following SNM-I.

Of 121 patients included in the study, 95 (79%) underwent MAC and 26 (21%) GA for SNM-I. No difference in the progression rate to SNM-II was noted between groups (MAC, 68/95 patients, 72%; GA, 19/26, 73%; p = 0.39). We also found no difference when comparing the GA group to the 26 most recent MAC patients (MAC, 20/26 patients, 77%; GA, 19/26, 73%; p = 0.48).

Types of anesthesia for SNM-I did not affect rate of progression to SNM-II. The result lends support to the reliance on motor responses alone for lead placement during SNM-I.