Differential Target Multiplexed Spinal Cord Stimulation: A UK Cost-Effectiveness Analysis.

OBJECTIVES: The aim of this economic analysis was to evaluate the cost-effectiveness of differential target multiplexed spinal cord stimulation (DTM-SCS) for treating chronic intractable low back pain, compared with conventional spinal cord stimulation (C-SCS) and conservative medical management (CMM), by updating and expanding the inputs for a previously published cross-industry model. MATERIALS AND METHODS: This model comprised a 12-month decision-tree phase followed by a long-term Markov model. Costs and outcomes were calculated from a UK National Health Service perspective, over a base-case horizon of 15 years and up to a maximum of 40 years. All model inputs were derived from published literature or other deidentified sources and updated to reflect recent clinical trials and costs. Deterministic and one-way sensitivity analyses were performed to calculate costs and quality-adjusted life-years (QALYs) across the 15-year time horizon and to explore the impact of individual parameter variability on the cost-effectiveness results. Probabilistic sensitivity analysis was undertaken to explore the impact of joint parameter uncertainty on the results. RESULTS: DTM-SCS was the most cost-effective option from a payer perspective. Compared with CMM alone, DTM-SCS was associated with an incremental cost-effectiveness ratio (ICER) of £6101 per QALY gained (incremental net benefit [INB] = £21,281). The INB for C-SCS compared with CMM was lower than for DTM-SCS, at £8551. For the comparison of DTM-SCS and C-SCS, an ICER of £897 per QALY gained was calculated, with a 99.5% probability of cost-effectiveness at a £20,000 per QALY threshold. CONCLUSIONS: Among patients with low back pain treated over a 15-year follow-up period, DTM-SCS and C-SCS are cost-effective compared with CMM, from both payer and societal perspectives. DTM-SCS is associated with a lower ICER than that of C-SCS. Wider uptake of DTM-SCS in the UK health care system is warranted to manage chronic low back pain.

Defining Short- and Long-Term Programming Requirements in Patients Treated With 10-kHz Spinal Cord Stimulation.

OBJECTIVES: High-frequency spinal cord stimulation (10-kHz SCS) has been shown to be an effective treatment for refractory low back pain and neck pain with and without limb pain in clinical trial and real-world studies. However, limited information is available in the literature on the type and frequency of programming parameters required to optimize pain relief. MATERIALS AND METHODS: Retrospective trial and postimplant clinical and system device data were analyzed from consecutive patients with neck pain and low back pain, with and without limb pain, from a single clinical site, including both thoracic and cervical lead placement. Best bipole, stimulation parameters, and outcomes, including pain relief, change in opioid medication use, sleep, and daily function, were analyzed. RESULTS: Of the 92 patients in the trial, 70 received a permanent implant. Of these, the mean duration of follow-up was 1.8 ± 1.3 years. Pain relief of ≥50% at the last follow-up was achieved by 64% of patients implanted; in addition, 65% reduced their opioid medication use; 65% reported improved sleep, and 71% reported improved function. There was some consistency between the "best" bipole at trial and permanent implant, with 82% of patients within one bipole location, including 54% of permanent implants who were using the same best bipole as at trial. After permanent implant, device reprogramming was minimal, with ≤one reprogramming change per patient per quarter required to maintain pain outcomes. CONCLUSIONS: In the study, 10-kHz SCS was an effective therapy for treating chronic pain, whereby a high responder rate (≥50% pain relief) was achieved with short time to pain relief in trial and maintained with limited device programming after permanent implant. The data presented here provide insight into the programming required during the trial and implant stages to obtain and maintain therapeutic efficacy.

Prevalence of Staphylococcus aureus Colonization in Spinal Cord Stimulator Surgical Procedures.

OBJECTIVES: To determine the prevalence of Staphylococcus aureus (S aureus) colonization for spinal cord stimulation (SCS) surgical patients and to identify specific at-risk patient populations. MATERIALS AND METHODS: Following Institutional Review Board approval, a retrospective review identified 232 SCS surgical patients. Preoperative Saureus nasal swab results were reviewed. Preoperative characteristics that included age at the time of procedure, body mass index, and medical comorbidities including, but not limited to, diabetes, smoking, obesity, and a history of surgical site infections were identified for each patient. The Clopper-Pearson method was used to calculate 95% CIs for proportions, and Fisher exact tests were used to estimate odds ratios (95% CI) for patient characteristics. RESULTS: The 232 SCS surgical patients who were identified underwent 396 unique neuromodulation procedures, with 100% screened for methicillin-resistant Saureus (MRSA) and 98.3% screened for methicillin-sensitive Saureus (MSSA). Overall, 23.3% (n = 54/232, 95% CI: 18.0%-29.3%) of patients were preoperatively colonized with Saureus, according to the following classification: 4.3% (n = 10/232, 95% CI: 2.1%-7.8%) were positive for MRSA and 20.2% (n = 46/228, 95% CI: 15.2%-26.0%) were positive for MSSA. Two patients were colonized with both MRSA and MSSA. Furthermore, 95.7% (n = 44/46, 95% CI: 85.2%-99.5%) of patients that were MSSA colonized were MRSA negative. Analysis of independent patient characteristics revealed anxiety and hypothyroidism as the only conditions associated with significantly increased odds of MRSA and MSSA colonization, respectively. CONCLUSIONS: Staphylococcusaureus colonization was present in >20% of SCS patients, with MSSA carriage occurring at a rate nearly five times that of MRSA. MRSA screening alone would not have identified >90% of Saureus-colonized patients with only MSSA carrier status. Therefore, consideration should be given to preoperative screening for both MRSA and MSSA. Since limited patient characteristics were associated with greater risk for Saureus colonization, all patient populations should be screened.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group.

BACKGROUND: The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial. METHODS: In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4-5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement. RESULTS: Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation. CONCLUSIONS: Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group.

BACKGROUND: The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial. METHODS: In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4-5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement. RESULTS: Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation. CONCLUSIONS: Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

The Use of Contrast Agents in Interventional Pain Procedures: A Multispecialty and Multisociety Practice Advisory on Nephrogenic Systemic Fibrosis, Gadolinium Deposition in the Brain, Encephalopathy After Unintentional Intrathecal Gadolinium Injection, and Hypersensitivity Reactions.

This Practice Advisory presents a comprehensive and evidence-based set of position statements and recommendations for the use of contrast media in interventional pain procedures. The advisory was established by an international panel of experts under the auspices of 11 multinational and multispecialty organizations based on a comprehensive review of the literature up to December 31, 2019. The advisory discusses the risks of using gadolinium-based contrast agents. These include nephrogenic systemic fibrosis, gadolinium brain deposition/retention, and encephalopathy and death after an unintentional intrathecal gadolinium injection. The advisory provides recommendations on the selection of a specific gadolinium-based contrast agent in patients with renal insufficiency, those who had multiple gadolinium-enhanced magnetic resonance imaging examinations, and in cases of paraspinal injections. Additionally, recommendations are made for patients who have a history of mild, moderate, or severe hypersensitivity reactions to contrast medium.

Current Perspectives on Neurostimulation for the Management of Chronic Low Back Pain: A Narrative Review.

Neurostimulation techniques for the treatment of chronic low back pain (LBP) have been rapidly evolving; however, questions remain as to which modalities provide the most efficacious and durable treatment for intractable axial symptoms. Modalities of spinal cord stimulation, such as traditional low-frequency paresthesia based, high-density or high dose (HD), burst, 10-kHz high-frequency therapy, closed-loop, and differential target multiplexed, have been limitedly studied to determine their efficacy for the treatment of axial LBP. In addition, stimulation methods that target regions other than the spinal cord, such as medial branch nerve stimulation of the multifidus muscles and the dorsal root ganglion may also be viable treatment options. Here, current scientific evidence behind neurostimulation techniques have been reviewed with a focus on the management of chronic axial LBP.

Long-Term Efficacy of a Novel Spinal Cord Stimulation Clinical Workflow Using Kilohertz Stimulation: Twelve-Month Results From the Vectors Study.

BACKGROUND AND OBJECTIVES: Multiple variables play a role in spinal cord stimulation (SCS) treatment outcomes, including patient anatomy, pain pattern, lead location, stimulation parameters, and so on. A wide range of stimulation parameters are considered safe and on-label, and as a result a growing number of new frequencies and frequency-combinations are being incorporated into standard practice. A standardized approach to therapy delivery may provide more consistent outcomes for more patients. The Vectors study evaluated whether there is significant sustained improvement in pain and functional outcomes when therapy is delivered using a standardized approach. MATERIALS AND METHODS: Vectors, a post-market, single-arm study evaluated the safety and efficacy of SCS with an implantable neurostimulator starting with 1 kHz stimulation, targeting the T9-T10 disc space following paresthesia mapping. Subjects with chronic intractable low back and leg pain (visual analogue scale [VAS] ≥ 50 mm) were enrolled. The primary endpoint was change in overall pain (VAS) at the three-month visit compared to baseline. Subjects were followed through 12 months. Secondary endpoints included changes in low back and leg pain, quality of life (European Quality of Life - Five Dimensions, EQ-5D-5L), disability (Oswestry Disability Index, ODI), individual subject goals, and subject satisfaction. RESULTS: There was a significant reduction in overall pain (VAS; 45.4 mm) through the three-month visit, which was sustained through 12 months. At 12 months, 79% of subjects had ≥50% improvement in at least one pain domain (overall, lowback or leg) with 85% of subjects reporting therapy satisfaction. There was a decrease in disability and an improvement in quality of life with 70% of subjects achieving a personal activity goal by the three-month visit. CONCLUSIONS: Long-term pain relief and improvement in quality of life and function were achieved when following a standardized workflow. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03345472.

The Technological Impact of COVID-19 on the Future of Education and Health Care Delivery.

BACKGROUND: The unexpected COVID-19 crisis has disrupted medical education and patient care in unprecedented ways. Despite the challenges, the health-care system and patients have been both creative and resilient in finding robust "temporary" solutions to these challenges. It is not clear if some of these COVID-era transitional steps will be preserved in the future of medical education and telemedicine. OBJECTIVES: The goal of this commentary is to address the sometimes substantial changes in medical education, continuing medical education (CME) activities, residency and fellowship programs, specialty society meetings, and telemedicine, and to consider the value of some of these profound shifts to "business as usual" in the health-care sector. METHODS: This is a commentary is based on the limited available literature, online information, and the front-line experiences of the authors. RESULTS: COVID-19 has clearly changed residency and fellowship programs by limiting the amount of hands-on time physicians could spend with patients. Accreditation Council for Graduate Medicine Education has endorsed certain policy changes to promote greater flexibility in programs but still rigorously upholds specific standards. Technological interventions such as telemedicine visits with patients, virtual meetings with colleagues, and online interviews have been introduced, and many trainees are "techno-omnivores" who are comfortable using a variety of technology platforms and techniques. Webinars and e-learning are gaining traction now, and their use, practicality, and cost-effectiveness may make them important in the post-COVID era. CME activities have migrated increasingly to virtual events and online programs, a trend that may also continue due to its practicality and cost-effectiveness. While many medical meetings of specialty societies have been postponed or cancelled altogether, technology allows for virtual meetings that may offer versatility and time-saving opportunities for busy clinicians. It may be that future medical meetings embrace a hybrid approach of blending digital with face-to-face experience. Telemedicine was already in place prior to the COVID-19 crisis but barriers are rapidly coming down to its widespread use and patients seem to embrace this, even as health-care systems navigate the complicated issues of cybersecurity and patient privacy. Regulatory guidance may be needed to develop safe, secure, and patient-friendly telehealth applications. Telemedicine has affected the prescribing of controlled substances in which online counseling, informed consent, and follow-up must be done in a virtual setting. For example, pill counts can be done in a video call and patients can still get questions answered about their pain therapy, although it is likely that after the crisis, prescribing controlled substances may revert to face-to-face visits. LIMITATIONS: The health-care system finds itself in a very fluid situation at the time this was written and changes are still occurring and being assessed. CONCLUSIONS: Many of the technological changes imposed so abruptly on the health-care system by the COVID-19 pandemic may be positive and it may be beneficial that some of these transitions be preserved or modified as we move forward. Clinicians must be objective in assessing these changes and retaining those changes that clearly improve health-care education and patient care as we enter the COVID era.

A Systematic Literature Review of Dorsal Root Ganglion Neurostimulation for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of dorsal root ganglion (DRG) stimulation for pain. DESIGN: Grade the evidence for DRG stimulation. METHODS: An international, interdisciplinary work group conducted a literature search for DRG stimulation. Abstracts were reviewed to select studies for grading. General inclusion criteria were prospective trials (randomized controlled trials and observational studies) that were not part of a larger or previously reported group. Excluded studies were retrospective, too small, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: DRG stimulation has Level II evidence (moderate) based upon one high-quality pivotal randomized controlled trial and two lower-quality studies. CONCLUSIONS: Moderate-level evidence supports DRG stimulation for treating chronic focal neuropathic pain and complex regional pain syndrome.

Guideline summary review: an evidence-based clinical guideline for the diagnosis and treatment of low back pain.

BACKGROUND CONTEXT: The North American Spine Society's (NASS) Evidence Based Clinical Guideline for the Diagnosis and Treatment of Low Back Pain features evidence-based recommendations for diagnosing and treating adult patients with nonspecific low back pain. The guideline is intended to reflect contemporary treatment concepts for nonspecific low back pain as reflected in the highest quality clinical literature available on this subject as of February 2016. PURPOSE: The purpose of the guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for adult patients with nonspecific low back pain. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition. STUDY DESIGN: This is a guideline summary review. METHODS: This guideline is the product of the Low Back Pain Work Group of NASS' Evidence-Based Clinical Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members utilized NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guideline was submitted to an internal and external peer review process and ultimately approved by the NASS Board of Directors. RESULTS: Eighty-two clinical questions were addressed, and the answers are summarized in this article. The respective recommendations were graded according to the levels of evidence of the supporting literature. CONCLUSIONS: The evidence-based clinical guideline has been created using techniques of evidence-based medicine and best available evidence to aid practitioners in the diagnosis and treatment of adult patients with nonspecific low back pain. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flowchart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx.

A Systematic Literature Review of Spine Neurostimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of spinal cord stimulation (SCS) for pain. DESIGN: Grade the evidence for SCS. METHODS: An international, interdisciplinary work group conducted literature searches, reviewed abstracts, and selected studies for grading. Inclusion/exclusion criteria included randomized controlled trials (RCTs) of patients with intractable pain of greater than one year's duration. Full studies were graded by two independent reviewers. Excluded studies were retrospective, had small numbers of subjects, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: SCS has Level 1 evidence (strong) for axial back/lumbar radiculopathy or neuralgia (five high-quality RCTs) and complex regional pain syndrome (one high-quality RCT). CONCLUSIONS: High-level evidence supports SCS for treating chronic pain and complex regional pain syndrome. For patients with failed back surgery syndrome, SCS was more effective than reoperation or medical management. New stimulation waveforms and frequencies may provide a greater likelihood of pain relief compared with conventional SCS for patients with axial back pain, with or without radicular pain.

Implementation of the North American Neuromodulation Society Mentorship Program: Recommendations and Survey Results of Participants.

INTRODUCTION: Despite Accredited Counsel of Graduate Medical Education (ACGME) guidance and criteria, there remains variability in training both within each specialty and across the specialties involved in the delivery of neuromodulation. NANS advocates for the efficacious and safe the implementation of neuromodulation and therefore an educational mentoring program with a defined educational platform is needed. MATERIALS AND METHODS: This is a structured, patient centered, and evidence-based approach mentorship program performed more than one year. Mentor/Mentee pairs started in 2015 and data collected were more than a five-year period. RESULTS: There was a 70%-86% response rate on each survey administered. All except one respondent reported that the mentorship program met their previously declared expectations. All the respondents self-reported at least a moderate increase in their knowledge in the field of neuromodulation while 54% of the respondents felt their knowledge in the field to have greatly increased. Most respondents reported an increase in the number of spinal cord stimulator trials and permanent implants performed after the mentorship program. The self-reporting of mentees competencies at the conclusion of the program was statistically significant for higher competency scores in all areas assessed. CONCLUSIONS: The NANs mentorship program met expectations and implementation goals by improving neuromodulation education including covering patient care, delivery, and training topics. The mentoring program provides a structured framework for extending formal physician neuromodulation education outside of direct fellowship training.

Spinal Cord Stimulation Infection Rate and Incremental Annual Expenditures: Results From a United States Payer Database.

OBJECTIVES: Surgical site infections (SSIs) result in significant negative clinical and economic outcomes. The objective of this study is to estimate annual health expenditures associated with spinal cord stimulation (SCS)-related infections. MATERIALS AND METHODS: Data from the Truven MarketScan® databases were used to identify patients with an SCS implant (2009-2014) and a continuous health plan enrollment for at least 12-months before and after implant (index date). Annual expenditures were estimated for patients with a device-related infection vs. those without infection since index date. A generalized linear model estimated annual expenditures attributable to device-related infection. Multivariable expenditure models were conducted separately for patients in initial and replacement groups, controlling for demographics, comorbidities, and clinical characteristics. RESULTS: The study included 6615 patients. Multivariable expenditure models revealed that patients with infection have higher annual expenditures than patients without infection. Estimated incremental annual healthcare expenditures for patients with an infection were $59,716 (95% CI: $48,965-$69,480) for initial implanted patients and $64,833 (95% CI: $37,377-$86,519) for replacement patients. Only 26% of patients who were explanted for infection underwent a reimplant. CONCLUSIONS: These results show the substantial expenditure burden associated with an SCS-related infection. Management of SCS-related infection is important from both clinical and economic standpoints. The economic and clinical data presented here reinforce the need for additional research and strategies for healthcare providers to minimize SCS infections. Future economic research is needed to further define the specific economic cost drivers associated with the extensive expenditure burden.