Initially, the tined leads used in this procedure were not compatible with magnetic resonance imaging (MRI), which restricted their use in patients requiring an MRI. When these patients with older SNS would undergo MRI scanning it could result in adverse effects such as thermal heating, tissue damage, pain, fracture of the lead, and permanent damage to the neurostimulator. In these specific patient cohorts who needed MRI, the option of SNS implantation for management of their OAB/ FI was not made available, or alternatively, if an MRI scan was required, the removal of the device was performed.
Due to the growing utilization of MRI for diagnostic purposes, there was a demand for an MRI-compatible SNS. Two companies, Axonic and Medtronic, developed SNS that are compatible with MRI technology. Both received approval from the Food and Drug Administration in 2019 and 2020 respectively, and they have since been implemented in clinical practice.
No multi-institutional data was available about the outcomes of the newer MRI-compatible Interstim.
We conducted a retrospective study in five high volume institutions to assess the efficacy and safety of the MRI-compatible InterStim™ SNS. The study included patients from UPMC Williamsport, the University of Minnesota, Advocate Lutheran General Hospital, the University of Wisconsin-Madison, and Ascension Providence Hospital- Southfield MI. The efficacy of the treatment was assessed by evaluating the frequency of symptoms before and after the treatment. The study included 73 patients. The average duration of follow-up was 6.62 ± 3.5 months (mean ± standard deviation). 93.2% of patient reported significant improvement in their symptoms.
Complications were noted in 7 patients, accounting for 9.6% of the total. These complications included nerve pain, hematoma, infection, lead fracture, and bleeding; however, only three patients (4.1%) of the total, had their implants removed for different reasons.
Our study demonstrates encouraging findings of high effectiveness, and favorable patient outcomes, with a new MRI compatible InterStim™ device.
This study was presented at ASCRS Annual Conference 2021 and at FIOD - Fecal Incontinence and Obstructed Defecation International Pelvic Floor Disorders Conference in Rome, Italy, Sept 2022 as the best oral presentation. It was recently published in general of Radiology and is listed for free access and download.
Written by:
- Maryam Aleissa, MD, Colorectal Surgery, Ascension Providence Hospital, Southfield MI
- Binit Katuwal, MD, Department of Surgery, Ascension Providence Hospital, Michigan State University College of Human Medicine, Southfield, MI
- Jasneet S. Bhullar, MD, General and Colorectal Surgery, Ascension Providence Hospital, Michigan State University College of Human Medicine, Southfield, MI