Vagus nerve stimulation after lead revision

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Vagus nerve stimulation (VNS) has demonstrated benefit in patients with medically intractable partial epilepsy. As in other therapies with mechanical devices, hardware failure occurs, most notably within the VNS lead, requiring replacement. However, the spiral-designed lead electrodes wrapped around the vagus nerve are often encased in dense scar tissue hampering dissection and removal. The objective in this study was to characterize VNS lead failure and lead revision surgery and to examine VNS efficacy after placement of a new electrode on the previously used segment of vagus nerve.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors reviewed all VNS lead revisions performed between October 2001 and August 2011 at the University of Iowa Hospitals and Clinics. Twenty-four patients underwent 25 lead revisions. In all cases, the helical electrodes were removed, and a new lead was placed on the previously used segment of vagus nerve. All inpatient and outpatient records of the 25 lead revisions were retrospectively reviewed.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Four cases were second lead revisions, and 21 cases were first lead revisions. The average time to any revision was 5 years (range 1.8–11.1 years), with essentially no difference between a first and second lead revision. The most common reason for a revision was intrinsic lead failure resulting in high impedance (64%), and the most common symptom was increased seizure frequency (72%). The average duration of surgery for the initial implantation in the 15 patients whose VNS system was initially implanted at the authors' institution was much shorter (94 minutes) than the average duration of lead revision surgery (173 minutes). However, there was a significant trend toward shorter surgical times as more revision surgeries were performed. Sixteen of the 25 cases of lead revision were followed up for more than 3 months. In 15 of these 16 cases, the revision was as effective as the previous VNS lead. In most of these cases, both the severity and frequency of seizures were decreased to levels similar to those following the previous implantation procedure. Only 1 complication occurred, and there were no postoperative infections.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Lead revision surgery involving the placement of a new electrode at the previously used segment of vagus nerve is effective at decreasing the seizure burden to an extent similar to that obtained following the initial VNS implantation. Even with multiple lead revisions, patients can obtain VNS efficacy similar to that following the initial lead implantation. There is a learning curve with revision surgery, and overall the duration of surgery is longer than for the initial implantation. Note, however, that complications and infection are rare.</jats:p></jats:sec>

Adjunctive vagus nerve stimulation for treatment-resistant bipolar disorder: managing device failure or the end of battery life

“…Eight of 10 seizure patients undergoing lead revisions because of device failure felt a return of their response similar to that before lead failure. Dlouhy et al 10 described 15/16 patients undergoing lead revisions followed for 3 months who returned to the previous level of seizure control.…”

Vagus nerve stimulation: Surgical technique of implantation and revision and related morbidity

“…Surgery for complete removal or revision and replacement of the device is to be considered in case of device malfunction, failure of VNS therapy, intolerable side effects, or because of patient's' specific request “to get rid of all foreign material” or “to become as before.”…”

“…Failure of the VNS device is not rare, since it accounts for 4–16.8% of cases and surgery for revision of VNS accounts for about one‐half of cases . In 2012, Dlohuy and colleagues reporting on the causes of malfunction in 25 cases of lead revision, found intrinsic microlesions in 64%, a visible fracture in 12%, a short circuit in 8%, and electrode coil dislocation in 4%. The two most recent series of surgical revisions for VNS malfunction and infection with the longest follow‐up have been reported by Couch and Revesz in 2016 after 14 and 25 years of follow‐up.…”

“…The surgical techniques of lead revision and replacement described in the literature include sharp and blunt dissection of helical electrodes and replacement, or blunt dissection combined with ultrasharp low‐voltage cautery dissection . There are many reports in the literature concerning outcomes and complications in surgery for complete vagus nerve stimulator lead revision . The most used technique is blunt and sharp dissection of the nerve to remove the helical electrodes .…”

Bioinspired Design of Peripheral Nerve Devices

“…77,98 Such situations require lead revision surgery, during which the patient is subject to a longer surgical procedure and old leads are often left attached to the nerve, necessitating identification of another location for the new lead. 77,96,99 Adverse factors associated with stimulator implantation are partially counteracted by increased familiarity with device implantation, removal, and reimplantation surgery, including strides in microsurgical technique; these advances have resulted in better preservation of nerve structure and function. 96,100−102 A particularly interesting advance was the implantation of a vagus nerve stimulator with the assistance of a robotic surgical system, which holds the potential to enhance surgical dexterity in anatomically inaccessible regions.…”