Removal of sacral neuromodulation quadripolar tined-lead using a straight stylet: description of a surgical technique

Background Up to 7.5% of tined-lead removals in patients having sacral neuromodulation (SNM) therapy are associated with a lead breakage. It is still unclear what adverse effects can be caused by unretrieved fragments. The aim of our study was to describe the lead removal technique we have been using for the last 2 years in our centre. Methods We retrospectively enrolled patients who had lead removal between January 2018 and January 2020 using our standardized technique. The novelty of the technique is in the use of the straight stylet, which is available in the quadripolar tined-lead kit. The stylet gives the electrode greater stiffness, reducing interactions with surrounding tissues and probability of damage or breakage during removal. Results In 59 patients (42 women, mean age 57.2 years [range 40–79 years]) the lead was removed using our standardized technique. In 44 of 59 patients, the tined-lead was removed within 2 months from the SNM-test, due to lack of beneficial effects. In 15 patients the electrode was removed because of failure of definitive implantation. Meantime from definitive implantable pulse generator (IPG) implantation to lead removal was 67.9 months. We recorded only 1 case of lead-breakage during removal: a female patient with a non-tined lead fixed on sacral bone, placed 18 years previously using an open technique. Conclusions Lead breakage during removal is not uncommon and adverse effects of retained fragments may occur. Our technique has been safely used for the last 2 years in our centre, with no episodes of lead breakage or retained fragments, except for one non-tined electrode.

Effect of defibrillation on the performance of an implantable vagus nerve stimulation system

Background Vagus Nerve Stimulation (VNS) delivers Autonomic Regulation Therapy (ART) for heart failure (HF), and has been associated with improvement in cardiac function and heart failure symptoms. VNS is delivered using an implantable pulse generator (IPG) and lead with electrodes placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on the VNS system. Methods DF testing was conducted on three ART IPGs (LivaNova USA, Inc.) according to international standard ISO14708-1, which evaluated whether DF had any permanent effects on the system. Each IPG was connected to a defibrillation pulse generator and subjected to a series of high-energy pulses. Results The specified series of pulses were successfully delivered to each of the three devices. All three IPGs passed factory electrical tests, and interrogation confirmed that software and data were unchanged from the pre-programmed values. No shifts in parameters or failures were observed. Conclusions Implantable VNS systems were tested for immunity to defibrillation, and were found to be unaffected by a series of high-energy defibrillation pulses. These results suggest that this VNS system can be used safely and continue to function after patients have been defibrillated.

Unexpected extrusion of the implantable pulse generator of the spinal cord stimulator - A case report -

Background: Despite significant technological advances in the implantable pulse generator (IPG), complications can still occur. We report a case that unexpected extrusion of the IPG of spinal cord stimulation (SCS) was promptly identified and successfully removed without any complications. Case: After a car accident 4 years ago, a 55-year-old man who was diagnosed with complex local pain syndrome in his right leg. The SCS was inserted with 2 leads, with the IPG being implanted in the right lower abdomen region. Four years later, he developed extrusion of the IPG from his abdominal region. This unexpected extrusion may have been related to pressure necrosis caused by continued compression of pocket site where a belt was frequently tied. The IPG and the leads were successfully removed without infection occurring. Conclusions: To prevent unexpected extrusion of IPG, it is necessary to consider in advance whether the pocket site is pressed against the belt.

Peripheral Nerve Stimulation of the Occipital Nerve to Treat Postherpetic Neuralgia

Background: Herpes zoster infection and subsequent postherpetic neuralgia can cause chronic neuropathic pain. Patients who do not respond well to pharmacotherapy require therapeutic options that are typically more invasive; our goal was to minimize invasiveness. Case Presentation: We present a case of intractable postherpetic neuralgia refractory to conservative pharmacological treatment and multiple occipital nerve blocks, which was successfully treated using peripheral occipital nerve stimulation (ONS) with an external implantable pulse generator (IPG). Conclusion: For interventionalists, one of the technical difficulties during ONS placement involves tunneling leads through the high-risk and difficult anatomy of the posterior neck. Further complicating placement and increasing patient discomfort are the long leads required for internal IPG implantation. The most commonly cited complication is lead migration or lead breakage. This difficulty can be attenuated by using an external IPG, such as was used in this case. An external IPG makes the ONS procedure significantly less invasive and reduces trauma and discomfort for the patient. Key words: Peripheral nerve stimulation (PNS), occipital nerve, postherpetic neuralgia (PHN), occipital nerve stimulation (ONS), implantable pulse generator (IPG), external IPG