A Case Series Review of Spinal Cord Stimulation Migration Rates With a Novel Fixation Device

Combined cervical and thoracic spinal cord stimulation for chronic pain: A systematic literature review

OBJECTIVES

Spinal cord stimulation (SCS) is conventionally placed at either cervical or thoracic spinal regions to treat chronic pain. However, for patients with multiarea pain, concomitant cervical and thoracic SCS (ctSCS) may be necessary to provide sufficient coverage. It remains unknown whether ctSCS is effective and safe. Thus, we aimed to survey the existing literature and assess the efficacy and safety of ctSCS.

METHODS

A systematic review of the literature was performed according to the 2020 PRISMA guidelines to investigate pain, functional, and safety outcomes related to ctSCS. Articles between 1990 and 2022 available through PubMed, Web of Science, Scopus, and Cochrane Library databases were included if they assessed these outcomes in the context of ctSCS. Data extracted from articles included study type, number of ctSCS implantations, stimulation parameters, indications for implantation, complications, and frequency. The Newcastle-Ottawa scale was used to assess risk of bias.

RESULTS

Three primary studies met our inclusion criteria. Overall, ctSCS was effective in providing analgesia. Pain severity was captured with patient-reported pain scales and changes in analgesic requirements. Various metrics were used to quantify quality of life and functional outcomes. Failed back surgery syndrome was the most common indication for ctSCS implantation. Implanted pulse generator pocket pain was the most common postoperative adverse event.

CONCLUSIONS

Despite the limited evidence available, ctSCS seems to be effective and generally well tolerated. The dearth of relevant primary literature illustrates a knowledge gap, and future studies are needed to better clarify the efficacy and safety profile of this SCS variant.

Migration of Epidural Leads During Spinal Cord Stimulator Trials

Objective

Lead migration is the most commonly reported complication of spinal cord stimulation (SCS) procedures and lead migration during trials of SCS can compromise both the success of the trial as well as the efficacy of subsequent implantation. Our objective was to examine the incidence and degree of intra-trial SCS lead migration and our hypothesis was that there would be a higher rate of significant radiographic lead migration during SCS trial than what has been previously published for permanently implanted leads.

Materials and Methods

We retrospectively assessed the radiographic location of SCS leads on final fluoroscopic imaging at the time of trial lead placement compared to thoracic radiographs obtained at the end of the SCS trial to quantify the rate and degree of migration during the trial. Thirty-five patients were included in the study with 69 leads assessed for radiographic degree of migration. The majority of patients were trialed utilizing paresthesia-free systems (57%) and the most common indication was for post-laminectomy syndrome (57%).

Results

In our series of 35 patients, on average there was 28 mm or 1.17 vertebral body levels of migration. No statistically significant correlation was found between fixation technique, physician experience, device manufacturer, patient age, sex, height or BMI and likelihood of significant radiographic migration.

Conclusion

In our study, lead migration appears to be a more significant occurrence during SCS trial than previously reported. Intra-trial migration presents a significant challenge for clinical care and examination of risk factors for migration and techniques for prevention are warranted.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations for Surgical Technique for Spinal Cord Stimulation

INTRODUCTION

The field of neurostimulation for the treatment of chronic pain is a rapidly developing area of medicine. Although neurostimulation therapies have advanced significantly as a result of technologic improvements, surgical planning, device placement, and postoperative care are of equal importance to optimize outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for these often-overlooked areas of neurostimulation practice.

MATERIALS AND METHODS

Authors were chosen based on their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from the last NACC publication in 2017 to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on evidence strength and consensus when evidence was scant.

RESULTS

This NACC project provides guidance on preoperative assessment, intraoperative techniques, and postoperative management in the form of consensus points with supportive evidence. These results are based on grade of evidence, strength of consensus, and expert opinion.

CONCLUSIONS

The NACC has given guidance for a surgical plan that encompasses the patient journey from the planning stage through the surgical experience and postoperative care. The overall recommendations are designed to improve efficacy and the safety of patients undergoing these neuromodulation procedures and are intended to apply throughout the international community.

Spinal cord stimulation programming: a crash course

The aim of this comprehensive review is to provide an instructional guide for providers regarding the parameters and programming of spinal cord stimulation (SCS) devices. Knowing these fundamentals will aid in providing superior pain relief to patients. SCS has four programmable parameters: contact (electrode) selection, amplitude, pulse width, and frequency. Each parameter needs to be accounted for when assessing which program works for which patient. Traditional open-loop systems allow for different "programs," or combinations of these four parameters, to be pre-set by the provider and medical device representative. These allow for flexibility in the type of stimulation delivered to the patient depending on activity. Patients are also given control over programs and changing the amplitudes of these programs. However, some open-loop systems place the burden of toggling between programs to manage pain control on patients, though this tends to be less in subparesthesia programs. Newer closed-loop systems make it possible for stimulation settings to automatically adjust in response to accelerometry and evoked compound action potential feedback, and therefore have the potential to streamline the patient experience. This article provides practitioners with the basic knowledge of SCS parameters and programming systems. Understanding their use is essential to providing optimal pain relief to patients.

Percutaneously Inserted Unilateral Lead Migration Salvaged with a Paddle Electrode

INTRODUCTION

Lead migration has been regarded as a frequent complication after percutaneous spinal cord stimulation (SCS). Thus far, repeated reinsertion of leads or replacement of paddle electrodes after removing percutaneous leads has been performed, but a salvage surgical technique using the remaining electrode has not been reported. Here, we describe a case in which unilateral lead migration was successfully treated with the insertion of a paddle electrode.

CASE SUMMARY

A 44-year-old male paraplegic patient with chronic neuropathic pain in the right leg and low back for 7 years underwent a percutaneous spinal cord stimulation procedure 5 times over 2 years because of repeated unilateral lead migration. The left lead underwent repeated migration and was difficult to reinsert due to epidural adhesion. After confirming the position and stimulation area of the remaining lead, we decided to insert another paddle electrode beside the remaining lead. We performed a T10 laminotomy and inserted a paddle electrode on the right side, using it in combination with the previous left lead. After surgery, the patient was satisfied with a wide coverage area.

DISCUSSION

We recommend salvage additional paddle electrode insertion rather than removing both leads during revision SCS. This surgical method increases the possibility of covering the dorsal column (DC) of the spinal cord, is cost effective, and decreases the possibility of failing to cover dorsal column using the paddle electrode during open surgery because the remaining lead's position and stimulation area guide the insertion of the additional paddle lead.

Percutaneous adjustment method for transversely migrated spinal cord stimulation leads: a technical report

Lead migration is the most common complication of spinal cord stimulation (SCS). However, the only corrective method for lead migration is revision surgery, which may cause additional complications. Here, we describe a new technique for adjusting a transversely migrated SCS lead. The medical records of four patients diagnosed with complex regional pain syndrome (n = 3) or failed back surgery syndrome (n = 1) who underwent implantation of percutaneous leads for SCS were retrospectively reviewed. Transverse lead migration was diagnosed radiographically after patients reported recurrence of pain or numbness in treated sites. The guide wire from the SCS implant kit was bent and inserted into the target epidural space using a 14-gauge Tuohy needle. When the guide wire contacted the migrated SCS lead, they were advanced to the correct location under C-arm guidance. After re-adjustment of the SCS lead, good coverage of the electrical stimulation was confirmed. Patients were followed for 9-19 months and they reported satisfactory pain relief and good electrical coverage after adjusting the SCS lead. Here, we describe a new technique for adjusting a transversely migrated SCS lead using a percutaneous epidural approach as a simple, safe, and cost-effective alternative to revision surgery.

The appropriate use of neurostimulation: avoidance and treatment of complications of neurostimulation therapies for the treatment of chronic pain. Neuromodulation Appropriateness Consensus Committee

INTRODUCTION

The International Neuromodulation Society (INS) has determined that there is a need for guidance regarding safety and risk reduction for implantable neurostimulation devices. The INS convened an international committee of experts in the field to explore the evidence and clinical experience regarding safety, risks, and steps to risk reduction to improve outcomes.

METHODS

The Neuromodulation Appropriateness Consensus Committee (NACC) reviewed the world literature in English by searching MEDLINE, PubMed, and Google Scholar to evaluate the evidence for ways to reduce risks of neurostimulation therapies. This evidence, obtained from the relevant literature, and clinical experience obtained from the convened consensus panel were used to make final recommendations on improving safety and reducing risks.

RESULTS

The NACC determined that the ability to reduce risk associated with the use of neurostimulation devices is a valuable goal and possible with best practice. The NACC has recommended several practice modifications that will lead to improved care. The NACC also sets out the minimum training standards necessary to become an implanting physician.

CONCLUSIONS

The NACC has identified the possibility of improving patient care and safety through practice modification. We recommend that all implanting physicians review this guidance and consider adapting their practice accordingly.

A Novel Nonanchoring Technique for Implantation of Paddle Leads in the Cervical Spine Under Conscious Sedation

OBJECTIVES

Spinal cord stimulation (SCS) revision surgery remains common, with a negative impact on cost-effectiveness and outcomes. The primary goal of this report was to retrospectively study the need for revision surgery in a cohort of complex regional pain syndrome type I (CRPS-1) patients with newly implanted cervical surgical paddle leads, focusing on a method of implantation to reduce the need for revision surgery.

METHODS

Fifteen patients underwent implantation of paddle SCS leads in the cervical spine with cervical laminotomies under conscious sedation for CRPS-1 from 2008 to 2012. Electrodes were not anchored and 11 of the electrodes were three-column paddle leads. A disinterested third party performed initial chart reviews, supplemented by subsequent telephone interviews. The need for revision surgery was the endpoint. A single surgeon performed all implants with a consistent method.

RESULTS

There were no paddle electrode lead revisions required for suboptimal lead placement, fracture, migration, or infection at a median follow-up period of 22 months.

CONCLUSIONS

This study is the first to report on: 1) cervical electrode implantation with no anchoring; and 2) cervical paddle lead implantation (including three-column paddles) performed under conscious sedation. The specific method of nonanchoring of the paddle implants under conscious sedation may have contributed to low electrode lead revision rates.