Spinal Cord Stimulation Implantation Research Articles

PO184 / #771 RETROGRADE INSERTION OF PADDLE LEADS FOR SPINAL CORD STIMULATION: E-POSTER VIEWING

Previous spine surgeries or areas of severe spinal stenosis in the vicinity of intended implantation of spinal cord stimulation (SCS) trial and/or permanent leads can pose challenges with associated increased procedural risks. One potential alternative is retrograde (caudal) insertion of a trial or permanent paddle lead by performing laminotomies above the targeted levels. The literature remains limited in the description of this technique with only handful of anecdotal case reports. Herein, the authors present a case series of retrograde insertion of paddle implants for SCS.

PO190 / #516 SPINAL CORD STIMULATOR IMPLANTATION IN PATIENT WITH HEMOPHILIA A: A CASE REPORT: E-POSTER VIEWING

Spinal cord stimulation (SCS) has shown to be a safe and effective treatment in chronic pain management of neuropathic pain conditions, including Complex regional pain syndrome (CRPS). Even though there are rarely reports of epidural bleeding or hematoma caused by the implantation of SCS, SCS is classified as a high-risk procedure for bleeding, especially in patients with bleeding disorders. Hemophilia A is an blood coagulation disorder resulting from deficiency of coagulation factor VIII, and these patients need adequate laboratory support, careful hemostasis planning before invasive intervention.

PO209 / #931 SLEEP QUALITY FOLLOWING SPINAL CORD STIMULATION FOR CHRONIC PAIN: INTERIM ANALYSIS: E-POSTER VIEWING

Difficulty initiating or maintaining sleep or overall poor sleep quality may occur in isolation or in combination with one another, leading to sleep disorders which are thought to occur in 30% of the general population and as much as 90% of chronic pain sufferers (Bjurstrom et al., 2021; Bjurstrom & Irwin, 2016; Finan et al., 2013; Roth, 2007). Central sensitization (CS) and sleep disturbances in people with chronic pain are closely linked. Spinal cord stimulation (SCS) appears improve an individual’s ability to sleep but the quality and pattern of improvement of sleep has not been examined. The objective is to (i) prospectively evaluate the quality and pattern of sleep following implantation of SCS using validated sleep questionnaires and to (ii) evaluate the inclusion sleep quality as a measurable outcome.

Spinal Cord Stimulation in Special Populations: Best Practices from the American Society of Pain and Neuroscience to Improve Safety and Efficacy.

Chronic bleeding disorders, allergy to implants, and chronic infections are all complicating factors when considering neuromodulation therapies. The American Society of Pain and Neuroscience (ASPN) determined a need for clinical guidance in these special patient populations that have increased risk of complications, in order to ensure patient safety and optimal outcomes with device implantation. The purpose of this publication was to review the published literature and explore the unique clinical challenges encountered among several special patient populations with relation to spinal cord stimulation. The executive board of the ASPN appointed a diverse group of well-established physicians to develop best practice guidelines regarding spinal cord stimulation implantation in these special populations. The physicians used the United States Preventive Services Task Force (USPSTF) structured guidelines for grading and level of certainty to make evidence-based recommendations about clinical practice. Where sufficient evidence was lacking to justify a USPSTF ranking, the physicians queried experts in neuromodulation and achieved consensus. These best practices and interventional guideline found the evidence for the use of neuromodulation in specialized patient populations to be relatively modest.

Combining Awake Anesthesia with Minimal Invasive Surgery Optimizes Intraoperative Surgical Spinal Cord Stimulation Lead Placement.

Spinal cord stimulation (SCS) is an effective and validated treatment to address chronic refractory neuropathic pain in persistent spinal pain syndrome-type 2 (PSPS-T2) patients. Surgical SCS lead placement is traditionally performed under general anesthesia due to its invasiveness. In parallel, recent works have suggested that awake anesthesia (AA), consisting of target controlled intra-venous anesthesia (TCIVA), could be an interesting tool to optimize lead anatomical placement using patient intra-operative feedback. We hypothesized that combining AA with minimal invasive surgery (MIS) could improve SCS outcomes. The goal of this study was to evaluate SCS lead performance (defined by the area of pain adequately covered by paraesthesia generated via SCS), using an intraoperative objective quantitative mapping tool, and secondarily, to assess pain relief, functional improvement and change in quality of life with a composite score. We analyzed data from a prospective multicenter study (ESTIMET) to compare the outcomes of 115 patients implanted with MIS under AA (MISAA group) or general anesthesia (MISGA group), or by laminectomy under general anesthesia (LGA group). All in all, awake surgery appears to show significantly better performance than general anesthesia in terms of patient pain coverage (65% vs. 34–62%), pain surface (50–76% vs. 50–61%) and pain intensity (65% vs. 35–40%), as well as improved secondary outcomes (quality of life, functional disability and depression). One step further, our results suggest that MISAA combined with intra-operative hypnosis could potentialize patient intraoperative cooperation and could be proposed as a personalized package offered to PSPS-T2 patients eligible for SCS implantation in highly dedicated neuromodulation centers.

Screening trials of spinal cord stimulation for neuropathic pain in England-A budget impact analysis.

Screening trials of spinal cord stimulation (SCS) prior to full implantation of a device are recommended by expert guidelines and international regulators. The current study sought to estimate the budget impact of a screening trial of SCS and the costs or savings of discontinuing the use of a screening trial. A budget impact analysis was performed considering a study population that reflects the size and characteristics of a patient population with neuropathic pain in England eligible for SCS. The perspective adopted was that of the NHS with a 5-year time horizon. The base case analysis indicate that a no screening trial strategy would result in cost-savings to the NHS England of £400,000–£500,000 per year. Sensitivity analyses were conducted to evaluate different scenarios. If ≥5% of the eligible neuropathic pain population received a SCS device, cost-savings would be >£2.5 million/year. In contrast, at the lowest assumed cost of a screening trial (£1,950/patient), a screening trial prior to SCS implantation would be cost-saving. The proportion of patients having an unsuccessful screening trial would have to be ≥14.4% for current practice of a screening trial to be cost-saving. The findings from this budget impact analysis support the results of a recent UK multicenter randomized controlled trial (TRIAL-STIM) of a policy for the discontinuation of compulsory SCS screening trials, namely that such a policy would result in considerable cost-savings to healthcare systems.

Lead and Pulse Generator Migration After Spinal Cord Stimulation Implantation: Insights From an Analysis of 7322 Patients

ObjectivesLead migration (LM) after spinal cord stimulation (SCS) implantation surgery is the most common device-related complication. Our study of lead and implantable pulse generator (IPG) migration using a large administrative claims data base aims to understand rates, risk factors, and outcomes after SCS implantation. Materials and MethodsThis retrospective cohort study used the IBM® MarketScan® (Armonk, NY) Commercial and Medicare Supplemental Databases from 2016 to 2018. Adult patients who underwent SCS surgical procedures with at least 90 days of follow-up were identified using Current Procedural Terminology (CPT®) codes. Patients with LM and IPG migration after SCS surgery were identified using the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10 CM) codes. Patients who underwent revision surgery after SCS implantation were identified using the CPT codes and ICD-10 CM codes. In addition, patient characteristics associated with LM or IPG migration, the temporal relationship of migration diagnosis, and revision surgery were evaluated in the cohort. Continuous outcomes were compared between groups using the two-sample Student t-test. The Fisher exact test was used to compare categorical outcomes between groups. ResultsA total of 7322 patients (64.4% percutaneous SCS) underwent SCS surgery during the study period. A total of 141 patients (1.9%) had LM or IPG migration. Of those, 116 patients (1.6%) had LM only; 18 patients (0.2%) had IPG migration; and seven patients (0.1%) had LM and IPG migration. The mean duration for migration diagnosis after initial SCS implantation was 168 (±163.1) days. The mean duration to revision surgery after the migration diagnosis was 12.3 (±35.2) days only. Most patients with migration (105, 74.5%) underwent revision surgery. Only younger age (p = 0.02) was associated with migration in this study. ConclusionsLM and pulse generator migration that required revision surgery occurred in a small proportion of patients who underwent SCS surgical procedures.

Exceptional Cases of Spinal Cord Stimulation for the Treatment of Refractory Cancer-Related Pain

ObjectivesCancer pain has traditionally been managed with opioids, adjuvant medications, and interventions including injections, neural blockade, and intrathecal pump (ITP). Spinal cord stimulation (SCS), although increasingly used for conditions such as failed back surgery syndrome and complex regional pain syndrome, is not currently recommended for cancer pain. However, patients with cancer-related pain have demonstrated benefit with SCS. We sought to better characterize these patients and the benefit of SCS in exceptional cases of refractory pain secondary to progression of disease or evolving treatment-related complications. Materials and MethodsThis was a single-center, retrospective case series at a tertiary cancer center. Adults ≥18 years old with active cancer and evolving pain secondary to disease progression or treatment, whose symptoms were refractory to systemic opioids, and who underwent SCS trial followed by percutaneous implantation between 2016 and 2021 were included. Descriptive statistics included mean, SD, median, and interquartile range (IQR). ResultsEight patients met the inclusion criteria. The average age at SCS trial was 60.0 (SD: ±11.6) years, and 50% were men. Compared with baseline, the median (IQR) change in pain score by numeric rating scale (NRS) after trial was −3 (2). At an average of 14 days after implant, the median (IQR) change in NRS and daily oral morphine equivalents were −2 (3.5) and −126 mg (1095 mg), respectively. At a median of 63 days after implant, the corresponding values were −3 (0.75) and −96 mg (711 mg). There was no significant change in adjuvant therapies after SCS implantation at follow-up. Six patients were discharged within two days after implantation. Two patients were readmitted for pain control within the follow-up period. ConclusionsIn patients with cancer-related pain, SCS may significantly relieve pain, reduce systemic daily opioid consumption, and potentially decrease hospital length of stay and readmission for pain control. It may be appropriate to consider an SCS trial before ITP in select cases of cancer-related pain.

Spinal cord stimulation therapy for patients with Parkinson’s disease and gait problems (STEP-PD): study protocol for an exploratory, double-blind, randomised, placebo-controlled feasibility trial

IntroductionGait difficulties are common in Parkinson’s disease (PD) and cause significant disability. These symptoms are often resistant to treatment. Spinal cord stimulation (SCS) has been found to improve gait, including...

Is Workers' Compensation Setting a Predictor for Spinal Cord Stimulation Failure?

Predictors of spinal cord stimulation (SCS) therapies' success remain elusive but the workers' compensation setting (WCS) has lower rates for success than non-WCS cohorts.1,2 The objective of this observational study was to compare the outcomes of SCS trials and implants in WCS versus no compensation setting (NCS).

How Was It for You?: Patients’ Perception of Long-Term Outcomes of Spinal Cord Stimulation

Spinal Cord Stimulation (SCS) is often used for treating refractory neuropathic pain.1 Though validated instruments are used to collect data on pain and related domains in patients who receive SCS implants,2 there is little information on patients’ perception of the impact of SCS. This study was conducted with the goal of ascertaining outcomes of SCS as relevant to patients.

Treatment of end-stage peripheral artery disease by neuromodulation.

Neuromodulation is a therapeutic option to improve limb salvage in end-stage peripheral arterial disease (PAD), but there is no consensus on its indication for spinal cord stimulation (SCS) in PAD patients. The aim of this study was to present the outcome of end-stage PAD patients treated with SCS. This study is a retrospective analysis based on a local prospective registry. Neuromodulation was performed if there was: 1) no revascularisation option, 2) no septicemia, 3) and Rutherford stage 4-6. The primary endpoint of the study was limb salvage. Secondary endpoints were reduction in pain or simply pain reduction pain (assessed using a visual anlog scale/VAS) and improvement in walking distance. Limb salvage was reached in 30/34 patients (88%). Patients reported a significant reduction in pain on the 10-point VAS scale from baseline (median = 7.5, IQR = 7-8) to follow-up at 2 years (median = 0, IQR 0-2.75), p < 0.001. Walking distance also improved from preoperative (median = 50 m, IQR = 20-50 m) to follow-up at 2 years (median = 150 m, IQR 50-272 m), p < 0.001. SCS implantation in patients with end-stage PAD can enable limb salvage in a high percentage of cases and increase mobility due to pain reduction. The role of microcirculation in these improvements needs to be investigated in further studies.

Does Fibromyalgia Affect the Outcomes of Spinal Cord Stimulation: An 11-Year, Multicenter, Retrospective Matched Cohort Study

BackgroundFibromyalgia is a prevalent disorder manifesting with widespread musculoskeletal pain and central sensitization, as well as fatigue, sleep issues, psychologic distress, and poor quality of life. Patients with fibromyalgia also may be diagnosed with other painful conditions amenable to treatment with spinal cord stimulation (SCS), although it is unclear how these patients respond to SCS compared with patients without fibromyalgia. Materials and MethodsWe performed an 11-year, multicenter, retrospective matched cohort study comparing SCS-treated patients with fibromyalgia and those without fibromyalgia. The primary outcome was comparison in mean calculated percentage pain relief between cohorts at six months after SCS implantation. Secondary outcomes included comparison of patient satisfaction between six and 12 months after SCS implantation, and percentage of patients reporting opioid intake and neuropathic medication intake at six months and 12 months after SCS implantation. Adjusted regression analysis was performed to make comparisons while adjusting for age, sex, body mass index, Charlson comorbidity index, preoperative opioid intake, and preoperative neuropathic medication intake. ResultsOf 90 patients with fibromyalgia who underwent SCS trial, 18 patients (20%) failed their SCS trial and did not proceed toward implantation. Sixty-eight patients with fibromyalgia were matched to 141 patients in the control cohort based on age, sex, Charlson comorbidity index, and the American Society of Anesthesiologists physical status score. At six months after SCS implantation, there was no statistical difference in calculated percentage change in pain intensity between the fibromyalgia cohort (46.6 ± 29.0) and the control cohort (50.9 ± 32.8; β, −18.4; 95% CI, −44.3 to 7.6; p = 0.157). At baseline, a greater percentage of patients in the fibromyalgia cohort reported preoperative opioid intake (51.5% vs 22.7%, p < 0.001) and preoperative neuropathic medication intake (67.6% vs 15.6%, p < 0.001). However, there was no difference between cohorts in the percentage of patients taking opioid or neuropathic medications at six months and 12 months after SCS implantation. Similarly, there was no difference between cohorts in the percentage of patients reporting satisfaction between six and 12 months. ConclusionPatients with fibromyalgia who received a diagnosis approved for treatment with SCS may expect similar post–SCS-implantation pain relief, overall satisfaction, and analgesic use rate to those of patients without fibromyalgia.

ID:16253 NACC Infection Control Recommendations and NANS Members Practice Patterns

Surgical site infections (SSI) are the second most common healthcare-related infections with high annual cost (10 billion US$). However, SSI rates have not significantly declined despite more than a decade of infection control recommendations by both Centers for Disease Control & Prevention (CDC) and Surgical Care Improvement Project (SCIP). Particularly, SSI rates after spinal cord stimulator (SCS) implantation range from 1 to 10%, with large studies reporting rates of 3.4 to 4.6%. In 2017, Neuromodulation appropriateness consensus committee (NACC) under auspices of International Neuromodulation Society, published evidence-based recommendations for infection prevention and management during SCS implantation. We conducted a survey of North American Neuromodulation Society (NANS) members to evaluate their knowledge and adherence to these guidelines and if knowledge and adherence varied by members’ practice setting.

Preoperative hemoglobin A1c and perioperative blood glucose in patients with diabetes mellitus undergoing spinal cord stimulation surgery: A literature review of surgical site infection risk.

The aim of our study was to review the surgical literature regarding the relationship between hemoglobin A1c (HbA1c), diagnosis of diabetes mellitus (DM), and risk of postoperative surgical site infection (SSI). A librarian-assisted literature search was performed with two goals: (1) identify surgical publications related to SSI and HbA1c values, and (2) identify publications reporting infection risk with DM in spinal cord stimulation (SCS), intrathecal drug delivery systems (IDDS), and cardiovascular implantable electronic device (CIED) implantation surgeries. Published guidelines on perioperative management of DM are reviewed. We identified 30 studies reporting SSI and HbA1c values. The literature review indicated that for many surgical procedures, elevated HbA1c is not correlated to rate of SSI. We identified 16 studies reporting infection rates within DM cohorts following SCS, IDDS, and CIED implantation surgeries. The data reviewed did not indicate DM as an independent risk factor for SSI. Preoperative HbA1c levels in patients with a history of DM is not a singularly sufficient tool to estimate risk of perioperative infection in SCS implantation surgery. Published guidelines on perioperative management of DM do not suggest a specific HbA1c above which surgery should be delayed; intentional perioperative glycemic control is recommended.

Preoperative Thoracic Spine Magnetic Resonance Imaging for Spinal Cord Stimulation: Should Such a Recommendation Be an Absolute Requirement?

ObjectiveCurrent published guidelines recommend advanced imaging, specifically, thoracic magnetic resonance imaging (MRI), prior to implantation of epidural paddle spinal cord stimulator (SCS) leads. Preoperative imaging may affect surgical approach to minimize risk of complications. We aimed to assess the impact of preoperative thoracic MRI on surgical planning in a large series of surgical paddle SCS lead placements in a real-world setting. Materials and MethodsThis is a retrospective study of a prospectively maintained data base of 160 patients treated by SCS with awake thoracic surgical paddle lead placement in a single academic functional neurosurgery center from 2013 to 2021. All patients had a thoracic MRI prior to implantation. Abnormal MRI findings were reviewed to determine their potential impact on the safety of surgical paddle lead placement. A minor impact was defined as anatomical areas to avoid with paddle lead placement. Major impacts included significant deviations from standard approach to electrode placement. ResultsNone of the 160 patients had signs or symptoms referable to thoracic spine pathology prior to lead implant. Sixty-seven had abnormal thoracic MRI findings, and 36 had abnormal MRI findings that impacted surgical planning. Thirty-one patients had MRI findings with minor impact. Five patients (more than 3%) had findings with major impact. ConclusionsThis is the largest case series assessing the impact of preoperative thoracic MRI on surgical planning for patients undergoing paddle SCS placement. Twenty-two percent of patients had MRI findings that impacted surgical planning with 3% requiring additional surgical decompression for safe paddle lead placement. Without advanced imaging to inform surgical planning, unnecessary risk may have been placed on these patients. Although such imaging has been recommended by consensus committees in published guidelines, our study is the first to present a large institutional experience of real-world data that demonstrates its importance.

ID:16396 Advancements in Wound Dressings for Neuromodulation

Lead migration, breakage, generator site pain, and surgical site infection (SSI) are common potential risks associated with spinal cord stimulator (SCS) trial and implantation.1 In recent years, numerous wound dressing optimization techniques have been proposed to reduce these complications; however, many haven’t been utilized in neuromodulation. Our goal is to present wound dressing optimization approaches that minimize loss of therapeutic effect due to lead migration/explant and avert the serious consequences associated with SSIs.

ID:16381 To Explant or Not to Explant: Differentiating Between IPG Pocket Hematoma and Infection

Infection is a known complication of spinal cord stimulator (SCS) implantation and has an estimated incidence of 2.4 to 3.1%. Most present as pocket infections and the feared complication of epidural abscess is rare. However, there is a paucity of data in the literature regarding the incidence of IPG pocket hematomas which share signs and symptoms with infection. While early detection of infection is based on physical examination, laboratory values, and imaging, these can all have significant overlap with IPG hematomas.

Preoperative evaluation of coagulation status in neuromodulation patients.

The incidence of hemorrhage in patients who undergo deep brain stimulation (DBS) and spinal cord stimulation (SCS) is between 0.5% and 2.5%. Coagulation status is one of the factors that can predispose patients to the development of these complications. As a routine part of preoperative assessment, the authors obtain prothrombin time (PT), partial thromboplastin time (PTT), and platelet count. However, insurers often cover only PT/PTT laboratory tests if the patient is receiving warfarin/heparin. The authors aimed to examine their experience with abnormal coagulation parameters in patients who underwent neuromodulation. Patients who underwent neuromodulation (SCS, DBS, or intrathecal pump implantation) over a 9-year period and had preoperative laboratory values available were included. The authors determined abnormal values on the basis of a clinical protocol utilized at their practice, which combined the normal ranges of the laboratory tests and clinical relevance. This protocol had cutoff values of 12 seconds and 39 seconds for PT and PTT, respectively, and < 120,000 platelets/μl. The authors identified risk factors for these abnormalities and described interventions. Of the 1767 patients who met the inclusion criteria, 136 had abnormal preoperative laboratory values. Five of these 136 patients had values that were misclassified as abnormal because they were within the normal ranges at the outside facility where they were tested. Fifty-one patients had laboratory values outside the ranges of our protocol, but the surgeons reviewed and approved these patients without further intervention. Of the remaining 80 patients, 8 had known coagulopathies and 24 were receiving warfarin/heparin. The remaining 48 patients were receiving other anticoagulant/antiplatelet medications. These included apixaban/rivaroxaban/dabigatran anticoagulants (n = 22; mean ± SD PT 13.7 ± 2.5 seconds) and aspirin/clopidogrel/other antiplatelet medications (n = 26; mean ± SD PT 14.4 ± 5.8 seconds). Eight new coagulopathies were identified and further investigated with hematological analysis. New anticoagulants and antiplatelet medications are not monitored with PT/PTT, but they affect coagulation status and laboratory values. Although platelet function tests aid in a subset of medications, it is more difficult to assess the coagulation status of patients receiving novel anticoagulants. PT/PTT may provide value preoperatively.

Feasibility of Spinal Cord Stimulation in Patients With Refractory Angina Pectoris and a Cardiac Implanted Electronic Device

ObjectivesFive to 10% of patients with stable coronary artery disease have refractory angina pectoris (RAP). These patients are restricted in performing daily activities due to angina pectoris. Spinal cord stimulation is a last resort treatment option. A number of this patient population also has an indication for a cardiac implanted electronic device (CIED) (pacemaker or implantable cardiac defibrillator). Manufacturers of spinal cord stimulators have stated a warning that interference can occur between the spinal cord stimulator and the CIED. Consequently, only a limited number of patients with RAP and a CIED have received a spinal cord stimulator. The aim of this retrospective cohort study is to determine whether spinal cord stimulation can be safely used in patients with RAP and a CIED. Materials and MethodsAll patients with RAP referred to our center were screened and included if 1) the patient received a spinal cord stimulator as treatment for RAP and if 2) the patient received a CIED either prior to or after spinal cord stimulator implantation. A transcutaneous electrical nerve stimulation (TENS) treadmill test was used as a screening tool to determine whether the patient was eligible for implantation of a spinal cord stimulator. Interference between the spinal cord stimulator and CIED was checked 1) after TENS treadmill test, 2) during implantation of spinal cord stimulator or CIED, 3) during mode switches of the SCS, and 4) during regular out patient follow-up. ResultsIn total, 22 patients had both a spinal cord stimulator and a CIED with an average follow-up duration of 44.5 months. No interference between the spinal cord stimulator and CIED was found. ConclusionSpinal cord stimulation can be safely applied in patients with a CIED provided that the CIED is checked for interference during implantation, if mode switches of the SCS occurred and once yearly after implantation according to routine follow-up.