Abstract: PD54-02
Sources of Funding: none

Introduction

Sacral neuromodulation (SNS) is an effective therapy; however, these devices are not approved to undergo magnetic resonance imaging (MRI) of sites other than the brain. Therefore, when non-brain MRIs are required, devices are often removed prior to imaging. We assessed the frequency of device removal for MRI and the subsequent clinical course of these patients.

Methods

A retrospective review of all SNS procedures in the urology department at a tertiary care center from 2010-2015 was performed and explants identified. Cases explanted for MRI were analyzed to collect demographics, clinical characteristics, and post-removal management. Descriptive statistics were calculated and presented as mean(standard deviation) or median[interquartile range] as appropriate.

Results

A total of 90 patients underwent SNS device removal, with 21(23%) occurring for MRI, of which all devices were implanted in 2012 or before. At explant, patients were 95%(N=20) female, 66[52-72] years of age, and had a 29.6[23.8-34.6] kg/m2 body mass index. Suboptimal symptom control from SNS was noted in 7(33%) patients prior to explantation and 4 patients in the cohort (19%) had Multiple Sclerosis. _x000D_ _x000D_ Of those explanted, 24% required MRI for neurologic and 57% for orthopedic concerns. The remaining MRI indications included abdominal masses (10%), genitourinary disease (5%), surveillance for prior spinal cord malignancy (5%), and cardiac disease (5%). Only 16 (76%) patients explanted ultimately underwent MRI, a median of 13[3-16] days after device removal. MRI results actively impacted clinical management in half of the imaged patients, with no pharmacologic interventions, but instead surgical evaluation (5), physical therapy/rehabilitation (1), an outpatient procedure (1), and a headache diary (1) being recommended. Only 10%(N=2) of explanted patients underwent device replacement, while 7 patients resumed medical therapy, 3 utilized intermittent self-catheterization or an indwelling catheter, 2 patients pursued Botulinum toxin, 1 sought care with a local urologist, and 1 underwent cystectomy and ileal conduit urinary diversion. Of the remainder, 1 is deceased and 4 were lost to follow-up. _x000D_

Conclusions

In patients receiving SNS therapy, device removal for MRI is a rare event, most commonly due to orthopedic and neurologic pathologies. About half of the MRIs performed impacted clinical management. As SNS replacement was rare in this cohort, research is needed on the safety of various MRI types with SNS devices in vivo.

Funding

none