How to avoid trivial mistakes during IPG replacement in patients treated with DBS for movement disorders: technical note from 13-years experience

Preliminary Experience with a Four-Lead Implantable Pulse Generator for Deep Brain Stimulation

BACKGROUND

Implantable pulse generators (IPGs) store energy and deliver electrical impulses for deep brain stimulation (DBS) to treat neurological and psychiatric disorders. IPGs have evolved over time to meet the demands of expanding clinical indications and more nuanced therapeutic approaches.

OBJECTIVES

The aim of this study was to examine the workflow of the first 4-lead IPG for DBS in patients with complex disease.

METHOD

The engineering capabilities, clinical use cases, and surgical technique are described in a cohort of 12 patients with epilepsy, essential tremor, Parkinson's disease, mixed tremor, and Tourette's syndrome with comorbid obsessive-compulsive disorder between July 2021 and July 2022.

RESULTS

This system is a rechargeable 32-channel, 4-port system with independent current control that can be connected to 8 contact linear or directionally segmented leads. The system is ideal for patients with mixed disease or those with multiple severe symptoms amenable to >2 lead implantations. A multidisciplinary team including neurologists, radiologists, and neurosurgeons is necessary to safely plan the procedure. There were no serious intraoperative or postoperative adverse events. One patient required revision surgery for bowstringing.

CONCLUSIONS

This new 4-lead IPG represents an important new tool for DBS surgery with the ability to expand lead implantation paradigms for patients with complex disease.

A multicenter, open-label, controlled trial on acceptance, convenience, and complications of rechargeable internal pulse generators for deep brain stimulation: the Multi Recharge Trial

OBJECTIVE

Rechargeable neurostimulators for deep brain stimulation have been available since 2008, promising longer battery life and fewer replacement surgeries compared to non-rechargeable systems. Long-term data on how recharging affects movement disorder patients are sparse. This is the first multicenter, patient-focused, industry-independent study on rechargeable neurostimulators.

METHODS

Four neurosurgical centers sent a questionnaire to all adult movement disorder patients with a rechargeable neurostimulator implanted at the time of the trial. The primary endpoint was the convenience of the recharging process rated on an ordinal scale from "very hard" (1) to "very easy" (5). Secondary endpoints were charge burden (time spent per week on recharging), user confidence, and complication rates. Endpoints were compared for several subgroups.

RESULTS

Datasets of 195 movement disorder patients (66.1% of sent questionnaires) with Parkinson's disease (PD), tremor, or dystonia were returned and included in the analysis. Patients had a mean age of 61.3 years and the device was implanted for a mean of 40.3 months. The overall convenience of recharging was rated as "easy" (4). The mean charge burden was 122 min/wk and showed a positive correlation with duration of therapy; 93.8% of users felt confident recharging the device. The rate of surgical revisions was 4.1%, and the infection rate was 2.1%. Failed recharges occurred in 8.7% of patients, and 3.6% of patients experienced an interruption of therapy because of a failed recharge. Convenience ratings by PD patients were significantly worse than ratings by dystonia patients. Caregivers recharged the device for the patient in 12.3% of cases. Patients who switched from a non-rechargeable to a rechargeable neurostimulator found recharging to be significantly less convenient at a higher charge burden than did patients whose primary implant was rechargeable. Age did not have a significant impact on any endpoint.

CONCLUSIONS

Overall, patients with movement disorders rated recharging as easy, with low complication rates and acceptable charge burden.

Neurological Worsening After Implantable Pulse Generator Replacement

BACKGROUND

Most of the implantable pulse generators (IPGs) in deep brain stimulation (DBS) used to date are non-rechargeable requiring regular replacements. IPG replacement is a minor surgical procedure, but adverse events including neurological worsening have been reported. In this study, we determine the possibility of neurological worsening after IPG replacement in Parkinson's disease (PD) cases on chronic DBS therapy (CDT) and its electrophysiological basis along with the therapeutic interventions used to alleviate them.

METHODS

This study is a retrospective chart review of PD cases on CDT followed at London Movement Disorders Centre from January 2010 to December 2016. Included cases were those who underwent one or more IPG replacement.

RESULTS

A total of 45 PD cases on CDT underwent 62 IPG replacements involving 121 channels. Neurological worsening was observed in 16 (35.5%) cases following 17 (27.4%) IPG replacements, all following dual-channel IPG replacements. Tremor (41.2%), speech (35.3%), and gait (23.5%) worsened most commonly. Deviation from the pre-replacement parameters including voltage and impedance resulting in change in total electrical energy delivered (TEED) was the most common electrophysiological correlate, observed in 82.4% (14/17) IPGs having neurological worsening. This included switched laterality in a dual-channel IPG. Neurological worsening in the remaining 17.6% cases was hardware-related.

CONCLUSION

Neurological worsening followed 27.4% of IPG replacements in PD cases on CDT with approximately 82.4% of these being avoidable by carefully monitoring stimulation parameters to match pre-replacement TEED values.

Is capsulectomy a feasible and useful measure in internal pulse generator replacement procedures? A technical note on the use of the PEAK PlasmaBlade(TM)

BACKGROUND

Implantable pulse generator (IPG) replacement is considered a simple procedure, but in case of extension cable damage or IPG pocket infection, it can dramatically affect a patient's quality of life. Higher risk of infection has been reported after IPG replacement procedures rather than after primary deep brain stimulation lead implantation, and some authors suggested that the IPG pocket capsule could play a pivotal role in causing it. In this technical note we present a capsulectomy technique adopted in IPG replacement procedures.

METHODS

Between July and October 2015, we carried out ten outpatient IPG replacement procedures at the chest and abdomen under local anesthesia for battery depletion using the PEAK PlasmaBlade(TM). All patients were followed for at least 2 months to rule out any hardware malfunction and infection.

RESULTS

All ten procedures were uneventful. No extension cable damage occurred. No IPG pocket infection occurred, also not in the follow-up. Mean surgical time was 30 min.

CONCLUSIONS

Complete capsulectomy is not feasible with basic surgical instruments, and the PEAK PlasmaBlade(TM) pencil appears to be a helpful tool in carrying out the procedure.