10 kHz spinal cord stimulation for the treatment of non-surgical refractory back pain: subanalysis of pooled data from two prospective studies

Potential Cost Savings with 60-day Peripheral Nerve Stimulation Treatment in Chronic Axial Low Back Pain

INTRODUCTION

Chronic axial low back pain (CLBP) that is not responsive to medication management or physical therapy often requires significant clinical intervention. Several interventional pain management options exist, including a 60-day peripheral nerve stimulation (PNS) treatment. This economic evaluation investigated the potential for projected cost savings associated with prioritizing 60-day PNS treatment relative to a 'standard of care' (SOC) approach (where patients do not have access to 60-day PNS).

METHODS

A decision tree (supervised machine learning) model tracked treatment progression across two hypothetical cohorts of US patients with CLBP in whom non-interventional options were ineffective (Cohort A: treatment starting with 60-day PNS followed by any additional interventional and surgical treatments versus Cohort B: standard of care interventional and surgical treatments without access to 60-day PNS). Treatment efficacy estimates were based on published success rates. Conditional on treatment failure, up to two additional interventions were considered within the 12-month time frame in both cohorts. SOC treatment options included epidural injection, radiofrequency ablation (RFA), basivertebral nerve ablation (BVNA), PNS permanent implant (PNS-PI), spinal cord stimulator (SCS) trial/implant, and spinal fusion surgery. Treatment choice probabilities in both cohort algorithms were based on clinician interviews. Costs were based on national Medicare reimbursement levels in the ambulatory surgery center (ASC) setting. Savings reflected the difference in projected costs between cohorts. A Monte Carlo simulation and sensitivity analyses were conducted to generate confidence intervals and identify important inputs.

RESULTS

The treatment algorithm which prioritized initial 60-day PNS treatment was projected to save $8056 (95% CI $6112-$9981) per patient during the first year of interventional treatment relative to the SOC approach.

CONCLUSIONS

Use of the 60-day PNS treatment as an initial interventional treatment in patients with CLBP may result in significant savings for Medicare. Projected savings may be even larger for commercial payers covering non-Medicare patients.

Network Meta-analysis and Economic Evaluation of Neurostimulation Interventions for Chronic Nonsurgical Refractory Back Pain

OBJECTIVES

Different types of spinal cord stimulation (SCS) have been evaluated for the management of chronic nonsurgical refractory back pain (NSRBP). A direct comparison between the different types of SCS or between closed-loop SCS with conventional medical management (CMM) for patients with NSRBP has not been previously conducted, and therefore, their relative effectiveness and cost-effectiveness remain unknown. The aim of this study was to perform a systematic review, network meta-analysis (NMA) and economic evaluation of closed-loop SCS compared with fixed-output SCS and CMM for patients with NSRBP.

METHODS

Databases were searched to September 8, 2023. Randomized controlled trials of SCS for NSRBP were included. The results of the studies were combined using fixed-effect NMA models. A cost-utility analysis was performed from the perspective of the UK National Health Service with results reported as incremental cost per quality-adjusted life-year (QALY).

RESULTS

Closed-loop SCS resulted in statistically and clinically significant reductions in pain intensity (mean difference [MD] 32.72 [95% CrI 15.69-49.78]) and improvements in secondary outcomes (Oswestry Disability Index [ODI] and health-related quality of life [HRQoL]) compared with fixed-output SCS at 6-month follow-up. Compared with CMM, both closed-loop and fixed-output SCS resulted in statistically and clinically significant reductions in pain intensity (closed-loop SCS vs. CMM MD 101.58 [95% CrI 83.73-119.48]; fixed-output SCS versus CMM MD 68.86 [95% CrI 63.43-74.31]) and improvements in secondary outcomes (ODI and HRQoL). Cost-utility analysis showed that closed-loop SCS dominates fixed-output SCS and CMM, and fixed-output SCS also dominates CMM.

DISCUSSION

Current evidence showed that closed-loop and fixed-output SCS provide more benefits and cost-savings compared with CMM for patients with NSRBP.

Electrical neuromodulation for the treatment of chronic pain: derivation of the intrinsic barriers, outcomes and considerations of the sustainability of implantable spinal cord stimulation therapies

INTRODUCTION

For over 60 years, spinal cord stimulation has endured as a therapy through innovation and novel developments. Current practice of neuromodulation requires proper patient selection, risk mitigation and use of innovation. However, there are tangible and intangible challenges in physiology, clinical science and within society.

AREAS COVERED

We provide a narrative discussion regarding novel topics in the field especially over the last decade. We highlight the challenges in the patient care setting including selection, as well as economic and socioeconomic challenges. Physician training challenges in neuromodulation is explored as well as other factors related to the use of neuromodulation such as novel indications and economics. We also discuss the concepts of technology and healthcare data.

EXPERT OPINION

Patient safety and durable outcomes are the mainstay goal for neuromodulation. Substantial work is needed to assimilate data for larger and more relevant studies reflecting a population. Big data and global interconnectivity efforts provide substantial opportunity to reinvent our scientific approach, data analysis and its management to maximize outcomes and minimize risk. As improvements in data analysis become the standard of innovation and physician training meets demand, we expect to see an expansion of novel indications and its use in broader cohorts.

Neuromodulation and Habituation: A Literature Review and Conceptional Analysis of Sustaining Therapeutic Efficacy and Mitigating Habituation

Spinal cord stimulation (SCS) is a therapeutic modality for the treatment of various chronic pain conditions that has rapidly evolved over the past 50 years. Unfortunately, over time, patients implanted with SCS undergo a habituation phenomenon leading to decreased pain relief. Consequently, the discovery of new stimulation waveforms and SCS applications has been shown to prolong efficacy and reduce explantation rates. This article explores various SCS waveforms, their applications, and proposes a graded approach to habituation mitigation. We suspect the neural habituation phenomenon parallels that seen in pharmacology. Consequently, we urge further exploration of the early introduction of these stimulation strategies to abate spinal cord stimulation habituation.

History and Future of Spinal Cord Stimulation

Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain refractory to medical management. An SCS system comprised one or more leads implanted in the epidural space, typically connected to an implantable pulse generator. This review discusses the history, indications, surgical technique, technological advances, and future directions of SCS.

Rates and Causes of Reoperations Following Spinal Cord Stimulation Within a 2-12 year Period

STUDY DESIGN

Retrospective study.

OBJECTIVE

Spinal cord stimulation has been mainly used for the management of postsurgical persistent neuropathic. The purpose of the study was to evaluate the rate and causes for reoperation following spinal cord stimulation, and to identify risk factors for reoperation.

METHODS

A retrospective study was conducted including patients who underwent surgical implantation of spinal cord stimulators within a 10-year period. The medical records of the included patients were reviewed for reoperations, demographics and certain clinical parameters. Demographics and clinical parameters were compared between patients with and without reoperations, and between patients with and without surgical site infections.

RESULTS

Overall, 1014 index procedures and 175 reoperations were performed within the study period. At least 1 reoperation was performed in 97 (9.5%) cases. The most common cause for revision was lead migration or lead misplacement (n = 31, 3.0%). In 31 (3.1%) cases the stimulator was removed due to no pain relief. Surgical site infection that required reoperation developed in 30 cases (2.9%). Younger age was associated with a need for reoperation (Odds Ratio [OR]: .97,95% Confidence Interval [CI]:0.95-.99, P = .005), while higher Body Mass index and diabetes were associated with development of infection (OR: 1.05, 95% CI: 1.00-1.11, P = .036 and OR: 2.42, 95% CI: 1.05-5.47, P = .033 respectively).

CONCLUSIONS

The results of this study indicate that certain measures could improve the overall reoperation rate after spinal cord stimulation, such as accurate positioning of the spinal cord stimulators and design of smaller generators. Moreover, preoperative optimization of patients could result in lower complication rate, lower reoperations rate, and subsequently better clinical outcomes.

Advances in Spinal Cord Stimulation

Neuromodulation, specifically spinal cord stimulation (SCS), has become a staple of chronic pain management for various conditions including failed back syndrome, chronic regional pain syndrome, refractory radiculopathy, and chronic post operative pain. Since its conceptualization, it has undergone several advances to increase safety and convenience for patients and implanting physicians. Current research and efforts are aimed towards novel programming modalities and modifications of existing hardware. Here we review the recent advances and future directions in spinal cord stimulation including a brief review of the history of SCS, SCS waveforms, new materials for SCS electrodes (including artificial skins, new materials, and injectable electrodes), closed loop systems, and neurorestorative devices.

Patient-Reported Satisfaction with Using a Rechargeable 10 kHz Spinal Cord Stimulation Device

Introduction

Chronic pain is a common clinical condition and is frequently treated with a variety of medications, but pharmacotherapy is oftentimes not the optimal long-term treatment option. Safe and effective long-term pain relief for trunk and limb pain is available using high-frequency spinal cord stimulation at 10 kHz (10 kHz SCS), which is delivered using a rechargeable implantable pulse generator (IPG). Although rechargeable devices have been shown to reduce patient risk and overall cost by eliminating the need for periodic surgeries to replace depleted non-rechargeable IPGs, there is little published evidence that rechargeable technology is practical and convenient for patients, especially in the context of 10 kHz SCS.

Objective

This analysis of real-world patients implanted with 10 kHz SCS devices was undertaken using patient data from an industry-maintained database to investigate whether there was a substantial burden associated with rechargeable SCS and the degree of patient satisfaction or dissatisfaction with 10 kHz SCS.

Results

This study included 10,391 men and women who were implanted with 10 kHz SCS devices to treat chronic pain of the trunk and/or limbs. They received stimulation for a median of 361 days (180-1550 days), and 65.48% had previous spine surgery. In this patient sample, most patients were satisfied with the efficacy of 10 kHz SCS, including 77% who would repeat the procedure and 71% who would recommend it to other patients with similar pain. In regards to IPG recharging, 70% were satisfied or very satisfied and 19% were neutral, and a majority of patients recharged their device daily for 30 to 60 minutes.

Conclusion

These results indicate most patients do not find IPG recharging inconvenient or burdensome. In addition, IPG recharging is not a barrier to the majority of patients benefitting from 10 kHz SCS for long-term pain relief.

Spinal Cord Stimulation Attenuates Neural Remodeling, Inflammation, and Fibrosis After Myocardial Infarction

OBJECTIVES

Spinal cord stimulation (SCS) is an established neuromodulation method that regulates the cardiac autonomic system. However, the biological mechanisms of the therapeutic effects of SCS after myocardial infarction (MI) remain unclear.

MATERIALS AND METHODS

Twenty-five rabbits were divided into five groups: SCS-MI (voltage: 0.5 v; pulse width: 0.2 ms; 50 Hz; ten minutes on and 30 minutes off; two weeks; n = 5), MI (n = 5), sham SCS-MI (voltage: 0 v; two weeks; n = 5), sham MI (n = 5), and blank control (n = 5) groups. MI was induced by permanent left anterior descending artery ligation. SCS-MI and sham SCS-MI rabbits received the corresponding interventions 24 hours after MI. Autonomic remodeling was evaluated using enzyme-linked immunosorbent assay and immunohistochemistry. Inflammation and myocardial fibrosis were assessed using immunohistochemistry, quantitative polymerase chain reaction, hematoxylin and eosin staining, Masson staining, and Western blot.

RESULTS

SCS improved the abnormal systemic autonomic activity. Cardiac norepinephrine decreased after MI (p < 0.01) and did not improve with SCS. Cardiac acetylcholine increased with SCS compared with the MI group (p < 0.05). However, no difference was observed between the MI and blank control groups. Growth-associated protein 43 (p < 0.001) and tyrosine hydroxylase (p < 0.001) increased whereas choline acetyltransferase (p < 0.05) decreased in the MI group compared with the blank control group. These changes were attenuated with SCS. SCS inhibited inflammation, decreased the ratio of phosphorylated-Erk to Erk (p < 0.001), and increased the ratio of phosphorylated-STAT3 to STAT3 (p < 0.001) compared with the MI group. Myocardial fibrosis was also attenuated by SCS.

CONCLUSIONS

SCS improved abnormal autonomic activity after MI, leading to reduced inflammation, reactivation of STAT3, and inhibition of Erk. Additionally, SCS attenuated myocardial fibrosis. Our results warrant future studies of biological mechanisms of the therapeutic effects of SCS after MI.

Spinal Cord High-Frequency Stimulation. The Current Experience and Future Directions

Spinal cord stimulation (SCS) is a neuromodulation technology that has emerged as a valid treatment for chronic intractable neuropathic pain. After conventional tonic SCS, new waveforms of stimulation, like high frequency (HF), have proved that they can provide safe and effective pain relief. In addition, SCS is now being utilized more broadly as a potential treatment for a range of indications, including motor disorders and spasticity. Our study presents a retrospective analysis of 20 patients with heterogenous aetiologies of neuropathic pain treated with HF stimulation, after a standardized protocol in a temporary trial. We observed a significant improvement in pain relief according to comparisons of numerical rating scale (NRS) scores before the procedure, after the clinical trial and at latest follow-up. Two unusual clinical cases were also reported, and the pertinent literature was discussed.

Spinal Cord Stimulation Meets Them All: An Effective Treatment for Different Pain Conditions. Our Experience and Literature Review

IntroductionSpinal Cord Stimulation (SCS) is an emerging minimally invasive technique which uses neuromodulation to manage different forms of intractable pain. SCS is a well-established option for the treatment of various pain conditions, and nowadays, indications are ever increasing.Materials and MethodsIn this study, we present our case series of 49 patients who underwent SCS at our Institution for the treatment of pain from different etiologies, and discuss our 10-year experience in SCS. For the purpose of this study, we also performed a systematic review of current indications and new perspectives in SCS.ResultsAmong our case series, patients were differentiated into two groups upon prior spinal surgery: patients who had undergone prior spinal surgery for back pain were defined as the "FBSS (failed back surgery syndrome) group," instead patient suffering from different types of pain but who had never undergone surgery were defined as the "naive group." As regards clinical response to SCS, 20 patients out of 36 (55.56%) were classified as responders in the FBSS group; in the "naïve" group, 10 patients out of 13 (76.92%) were classified as responders. Among the "not responders" group, several patients suffered from infections.Of the recent literature about SCS, 2124 records were screened and 37 studies were finally included in the qualitative synthesis for our systematic review.DiscussionIn case of FBSS, surgical revision is often associated with a high morbidity and corresponding low rates of success. Unfortunately, patients affected by chronic pain often become refractory to conservative treatments. Spinal Cord Stimulation (SCS) is nowadays considered as an effective therapy for several chronic and neuropathic pain conditions, such as failed back surgery syndrome. As regards the economic impact of SCS, implantation of an SCS system results in short-term costs increase, but the annual cumulative costs decrease during the following years after implantation, when compared to the costs of conventional management. Beyond the application for the treatment of FBSS, SCS has also been used for the treatment of other types of chronic non-oncological pain such as neuropathic pain and chronic back pain ineligible for surgical intervention. This evidence paved the way to establishing the potential role of SCS also for the treatment of oncological pain. However, the effectiveness and relative safety of SCS for cancer-related pain has not yet been adequately established.ConclusionsSpinal Cord Stimulation is a well-established treatment option in for FBSS. Beyond that, SCS has also been used for the treatment of "naive" patients, suffering from other types of chronic, both oncological and non-oncological, medical-refractory pain such as neuropathic pain and chronic back pain ineligible for surgical intervention.

Cross-Country Differences in Pain Medication Before and After Spinal Cord Stimulation: A Pooled Analysis of Individual Patient Data From Two Prospective Studies in the United Kingdom and Belgium

OBJECTIVES

Spinal cord stimulation (SCS) can reduce the need for opioids; however, the influence on the full spectrum of pain medication is less known. The aims of this study were to explore general prescription practices for patients scheduled for SCS, potential differences in prescriptions between Belgium and United Kingdom, and the influence of SCS on pain medication.

MATERIALS AND METHODS

Individual patient data from the TRIAL-STIM study in the United Kingdom and DISCOVER in Belgium were pooled. Medication use was collected before SCS and three months after SCS from 180 chronic pain patients. The Medication Quantification Scale III (MQS) was used to calculate a total score for medication use, as well as subscores for several classes. Differences in prescription practices between United Kingdom and Belgium were evaluated with two-sided Wilcoxon tests. To evaluate differences in medication use after three months of SCS between United Kingdom and Belgium, Tweedie-generalized linear models were calculated.

RESULTS

There was a statistically significant difference (-6.40 [95% CI from -3.40 to -9.10]) between the median total MQS score in United Kingdom and Belgium before SCS. Additionally, a significant difference was found for nonsteroidal anti-inflammatory drugs (NSAIDs) (-3.40 [95% CI -3.40 to -6.80]), neuropathic agents (-2.30 [95% CI -0.40 to -3.80]), and benzodiazepines (1.83e^-05 [95% CI 2.64^-05 to 7.45^-05]) between United Kingdom and Belgium, before SCS. Tweedie-generalized models revealed a statistically significant interaction between country and time for MQS, neuropathic agents, and opioids.

CONCLUSIONS

Our combined analysis revealed differences in prescription practice in patients scheduled for SCS implantation between Belgium and United Kingdom. NSAIDs and neuropathic mood agents are more frequently used in the United Kingdom, presumably due to easier access to repeat prescriptions and over the counter medications. After three months of SCS, a decrease in medication use is observed in both countries, with higher reductions in Belgium, presumably due to strict regulations concerning reimbursement criteria.

Retrospective Efficacy and Cost-Containment Assessment of 10 kHz Spinal Cord Stimulation (SCS) in Non-Surgical Refractory Back Pain Patients

Background

Non-surgical refractory back pain (NSRBP) is persistent, severe back pain that is not considered surgically correctable. Published studies have demonstrated clinically important long-term improvement in pain and functional capacity when 10kHz spinal cord stimulation (SCS) is used to treat NSRBP. This study examines if real-world patients in interventional pain practice obtain the same outcomes, and have any reduction in health care utilization (HCU) following 10kHz SCS implant.

Methods

We conducted a retrospective chart review of 105 patients from two clinical sites who underwent implantation of 10kHz SCS for NSRBP. The three most frequent diagnoses were lumbosacral radiculopathy, degenerative disc disease (DDD)/discogenic back pain and foraminal stenosis. The complete set of patient-level electronic data, including clinical outcomes, HCU, and at least 12 months (12M) follow-up were available in 90 subjects.

Results

The 90 analyzed patients were 63.9 years old (median 67) with an average of 10.2 years since back pain diagnosis. Reported pain on the Visual Analog Scale (VAS) decreased from 7.78±1.3 cm to 3.4±2.4 cm at 12M after SCS implant (p<0.001). Opioid usage (n = 65) decreased from 57.9±89.9 mg to 34.3±66.4 mg MSO4 equivalents (p = 0.004) at 12M. There were 46 patients on various doses of anticonvulsants, mostly gabapentin. The average dose decreased from 1847.91±973.6 mg at baseline to 1297.9±1184.6 mg at 12M after implant (p = 0.016). HCU was analyzed comparing the 12M before to the 12M after implant. Number of office visits decreased from 10.83±8.0 per year to 8.86±7.64 (p = 0.036), number of procedures to control chronic pain decreased from 2.2±1.9 to 0.6±1.2 (p<0.001). There was no significant change in number of imaging procedures, hospital admissions, or days spent in the hospital.

Conclusion

10kHz SCS warrants consideration as a therapeutic option for NSRBP patients and appears to provide a substantial reduction in HCU in the year following implant.

A Review of Functional Restoration From Spinal Cord Stimulation in Patients With Spinal Cord Injury

Traumatic spinal cord injury often leads to loss of sensory, motor, and autonomic function below the level of injury. Recent advancements in spinal cord electrical stimulation (SCS) for spinal cord injury have provided potential avenues for restoration of neurologic function in affected patients. This review aims to assess the efficacy of spinal cord stimulation, both epidural (eSCS) and transcutaneous (tSCS), on the return of function in individuals with chronic spinal cord injury. The current literature on human clinical eSCS and tSCS for spinal cord injury was reviewed. Seventy-one relevant studies were included for review, specifically examining changes in volitional movement, changes in muscle activity or spasticity, or return of cardiovascular pulmonary, or genitourinary autonomic function. The total participant sample comprised of 327 patients with spinal cord injury, each evaluated using different stimulation protocols, some for sensorimotor function and others for various autonomic functions. One hundred eight of 127 patients saw improvement in sensorimotor function, 51 of 70 patients saw improvement in autonomic genitourinary function, 32 of 32 patients saw improvement in autonomic pulmonary function, and 32 of 36 patients saw improvement in autonomic cardiovascular function. Although this review highlights SCS as a promising therapeutic neuromodulatory technique to improve rehabilitation in patients with SCI, further mechanistic studies and stimulus parameter optimization are necessary before clinical translation.

A case series of new radicular pain following the insertion of spinal cord stimulator

Purpose

Although spinal cord stimulation (SCS) is a safe procedure, equipment-related, biological and neurological complications have been observed in previous research, particularly case reports. No reports of new neuropathic pain in the absence of neurological deficit or positive MRI findings have been described. We detail three cases of new-onset radicular pain in the L5/S1 dermatome following insertion of SCS.

Methods

This was a retrospective case series of three patients. Details of clinical background, indications for SCS and events occurring during insertion and further management were recorded.

Results

All three cases were technically difficult and required multiple epidural entry levels, with repeated passage of the electrode into and within the epidural space. All cases involved accessing epidural space T12/L1 and L1/L2. A possible explanation for the new-onset radicular pain could concern oedema to the conus medullaris, resulting from repeated passage of the electrode at the T12/L1 level. Alternative explanations could be direct trauma to transiting nerve roots, neuroplastic changes resulting in peripheral and central sensitisation and immune-mediated nerve injury.

Conclusion

MRI imaging should be analysed prior to the SCS procedure to identify the level of the conus medullaris, with the aim of avoiding repeated passage of electrodes at that level. Unintended neurological adverse events should be discussed with patients during the consent process. Careful patient selection and psychological screening may also help identify patients who may be unlikely to respond to SCS therapy. Further reporting of new radiculopathic pain following SCS insertion is required to strengthen understanding of its potential causes.

Treatment of nonsurgical refractory back pain with high-frequency spinal cord stimulation at 10 kHz: 12-month results of a pragmatic, multicenter, randomized controlled trial

OBJECTIVE

Spinal cord stimulation (SCS) at 10 kHz (10-kHz SCS) is a safe and effective therapy for treatment of chronic low-back pain. However, it is unclear from existing evidence whether these findings can be generalized to patients with chronic back pain that is refractory to conventional medical management (CMM) and who have no history of spine surgery and are not acceptable candidates for spine surgery. The authors have termed this condition "nonsurgical refractory back pain" (NSRBP) and conducted a multicenter, randomized controlled trial to compare CMM with and without 10-kHz SCS in this population.

METHODS

Patients with NSRBP, as defined above and with a spine surgeon consultation required for confirmation, were randomized 1:1 to patients undergoing CMM with and without 10-kHz SCS. CMM included nonsurgical treatment for back pain, according to physicians' best practices and clinical guidelines. Primary and secondary endpoints included the responder rate (≥ 50% pain relief), disability (Oswestry Disability Index [ODI]), global impression of change, quality of life (EQ-5D-5L), and change in daily opioid use and were analyzed 3 and 6 months after randomization. The protocol allowed for an optional crossover at 6 months for both arms, with observational follow-up over 12 months.

RESULTS

In total, 159 patients were randomized; 76 received CMM, and 69 (83.1%) of the 83 patients who were assigned to the 10-kHz SCS group received a permanent implant. At the 3-month follow-up, 80.9% of patients who received stimulation and 1.3% of those who received CMM were found to be study responders (primary outcome, ≥ 50% pain relief; p < 0.001). There was also a significant difference between the treatment groups in all secondary outcomes at 6 months (p < 0.001). In the 10-kHz SCS arm, outcomes were sustained, including a mean 10-cm visual analog scale score of 2.1 ± 2.3 and 2.1 ± 2.2 and mean ODI score of 24.1 ± 16.1 and 24.0 ± 17.0 at 6 and 12 months, respectively (p = 0.9). In the CMM arm, 74.7% (56/75) of patients met the criteria for crossover and received an implant. The crossover arm obtained a 78.2% responder rate 6 months postimplantation. Five serious adverse events occurred (procedure-related, of 125 total permanent implants), all of which resolved without sequelae.

CONCLUSIONS

The study results, which included follow-up over 12 months, provide important insights into the durability of 10-kHz SCS therapy with respect to chronic refractory back pain, physical function, quality of life, and opioid use, informing the current clinical practice for pain management in patients with NSRBP.

Dural Puncture During Spinal Cord Stimulator Lead Insertion: Analysis of Practice Patterns

Background

Spinal cord stimulation (SCS) is an important modality for intractable pain not amenable to less conservative measures. During percutaneous SCS lead insertion, a critical step is safe access to the epidural space, which can be complicated by a dural puncture.

Objectives

In this review, we present and analyze the practices patterns in the event of a dural puncture during a SCS trial or implantation.

Methods

We conducted a survey of the practice patterns regarding spinal cord stimulation therapy. The survey was administered to members of the Spine Intervention Society and American Society of Regional Anesthesia specifically inquiring decision making in case of inadvertent dural puncture during spinal cord stimulator lead insertion.

Results

A maximum of 193 responded to a question regarding dural punctures while performing a SCS trial and 180 responded to a question regarding dural punctures while performing a SCS implantation. If performing a SCS trial and a dural puncture occurs, a majority of physicians chose to continue the procedure at a different level (56.99%), followed by abandoning the procedure (27.98%), continuing at the same level (10.36%), or choosing another option (4.66%). Similarly, if performing a permanent implantation and a dural puncture occurs, most physicians chose to continue the procedure at a different level (61.67%), followed by abandoning the procedure (21.67%), continuing at the same level (10.56%), or choosing another option (6.11%).

Conclusions

Whereas the goals of the procedure would support abandoning the trial but continuing with the permanent in case of inadvertent dural puncture, we found that decision choices were minimally influenced by whether the dural puncture occurred during the trial or the permanent implant. The majority chose to continue with the procedure at a different level while close to a quarter chose to abandon the procedure. This article sets a time stamp in practice patterns from March 20, 2020 to June 26, 2020. These results are based on contemporary SCS practices as demonstrated by this cohort, rendering the options of abandoning or continuing after dural puncture as reasonable methods. Though more data is needed to provide a consensus, providers can now see how others manage dural punctures during SCS procedures.

Non-Spinal Neuromodulation of the Lumbar Medial Branch Nerve for Chronic Axial Low Back Pain: A Narrative Review

Chronic low back pain remains highly prevalent, costly, and the leading cause of disability worldwide. Symptoms are complex and treatment involves an interdisciplinary approach. Due to diverse anatomical etiologies, treatment outcomes with interventional options are highly variable. A novel approach to treating chronic axial low back pain entails the use of peripheral nerve stimulation to the lumbar medial branch nerve, and this review examines the clinical data of the two different, commercially available, non-spinal neuromodulation systems. This review provides the clinician a succinct narrative that presents up-to-date data objectively. Our review found ten clinical studies, including one report of two cases, six prospective studies, and three randomized clinical trials published to date. Currently, there are different proposed mechanisms of action to address chronic axial low back pain with different implantation techniques. Evidence suggests that peripheral nerve stimulation of the lumbar medial branch nerve may be effective in improving pain and function in patients with chronic axial low back pain symptoms at short and long term follow up, with good safety profiles. Further long-term data is needed to consider this intervention earlier in the pain treatment algorithm, but initial data are promising.

Contralateral and Lateral Views: Analysis of the Technical Aspects of Spinal Cord Stimulator Lead Insertion

Background

Spinal cord stimulation (SCS) is an established treatment modality for neuropathic pain. The critical part of this technique is safe access to the epidural space for lead placement. There have been innovations in radiological views, improving access to the epidural space.

Objectives

This study analyzes the adoption of these technical advantages in daily practice

Methods

We conducted a survey of members in the Spine Intervention Society and American Society of Regional Anesthesia in regard to the practice patterns in SCS therapy. Here we present our findings regarding the use of contralateral oblique (CLO) and lateral views as well direct upper thoracic or cervicothoracic access for SCS lead insertion

Results

A total of 195 unique responses were received between March 20, 2020 and June 26, 2020. Forty-five percent of respondents “always used” the lateral view technique while 15% “always used” CLO view for SCS lead insertion. Overall, sixty-five percent of respondents used the CLO view with varying frequency. Cervical and upper thoracic approach for cervical SCS lead placement is always or often used by 66.8% of the respondents.

Conclusions

A depth view (CLO or lateral) is always used by only 45 - 60% of the respondents and CLO view has been rapidly adopted in clinical practice for SCS lead insertion. Direct cervicothoracic and upper thoracic is the preferred approach for cervical lead placement by the majority.

10 kHz Spinal Cord Stimulation for the Treatment of Non-Surgical Refractory Back Pain: A Case Report

Back pain is one of the most common healthcare burdens in the United States and is the number one cause of disability worldwide. Treatment options for back pain usually emphasizes conservative modalities such as reassurance, education, physical therapy, cognitive behavioral therapy, medication management, and interventional pain procedures. Spinal cord stimulation (SCS) is a minimally invasive and reversible therapy used to treat various pain syndromes. The primary indications for SCS therapy are failed back surgery syndrome and complex regional pain syndrome. However, recent advances in therapy have expanded the use of SCS for a variety of chronic pain conditions including nonsurgical back pain and radiculopathy. We present the case of a patient with low back and lumbar radicular pain complaints that were not responsive to traditional conservative and interventional options who was successfully treated with 10 kHz spinal cord stimulation.

The Role of Spinal Cord Stimulation in Reducing Opioid Use in the Setting of Chronic Neuropathic Pain: A Systematic Review

OBJECTIVE

The aim was to examine research on the impact of spinal cord stimulation (SCS) on the reduction of preimplantation opioid dose and what preimplantation opioid dose is associated with a reduction or discontinuation of opioid use postimplantation.

METHODS

Systematic review of literature from PubMed, Web of Science, and Ovid Medline search of "opioid" and "pain" and "spinal cord stimulator." Inclusion criteria included original research providing data on SCS preimplantation opioid dosing and 12 months postimplantation opioid dosing or that correlated specific preimplantation opioid dose or opioid dose cutoff with significantly increased likelihood of opioid use discontinuation at 12 months postimplantation.

RESULTS

Systematic review of the literature yielded 17 studies providing data on pre-SCS and post-SCS implantation dose and 4 providing data on the preimplantation opioid dose that significantly increased likelihood of opioid use discontinuation at 12 months postimplantation. Data from included studies indicated that SCS is an effective tool in reducing opioid dose from preimplantation levels at 12 months postimplantation. Data preliminarily supports the assertion that initiation of SCS at a preimplantation opioid dose of ≤20 to ≤42.5 morphine milligram equivalents increases the likelihood of postimplantation elimination of opioid use.

DISCUSSION

SCS is an effective treatment for many types of chronic pain and can reduce or eliminate chronic opioid use. Preimplantation opioid dose may impact discontinuation of opioid use postimplantation and the effectiveness of SCS in the relief of chronic pain. More research is needed to support and strengthen clinical recommendations for initiation of SCS use at lower daily opioid dose.

Ethical Considerations in the Implantation of Neuromodulatory Devices

OBJECTIVES

Neuromodulatory devices are increasingly used by neurosurgeons to manage a variety of chronic conditions. Given their potential benefits, it is imperative to create clear ethical guidelines for the use of these devices. We present a tiered ethical framework for neurosurgeon recommendations for the use of neuromodulatory devices.

MATERIALS AND METHODS

We conducted a literature review to identify factors neurosurgeons should consider when choosing to offer a neuromodulatory device to a patient.

RESULTS

Neurosurgeons must weigh reductions in debilitating symptoms, improved functionality, and preserved quality of life against risks for intraoperative complications and adverse events due to stimulation or the device itself. Neurosurgeons must also evaluate whether patients and families will maintain responsibility for the management of neuromodulatory devices. Consideration of these factors should occur on an axis of resource allocation, ranging from provision of neuromodulatory devices to those with greatest potential benefit in resource-limited settings to provision of neuromodulatory devices to all patients with indications in contexts without resource limitations. Neurosurgeons must also take action to promote device effectiveness throughout the duration of care.

CONCLUSIONS

Weighing risks and benefits of providing neuromodulatory devices and assessing ability to remain responsible for the devices on the level of the individual patient indicate which patients are most likely to achieve benefit from these devices. Consideration of these factors on an axis of resource allocation will allow for optimal provision of neuromodulatory devices to patients in settings of varied resources. Neurosurgeons play a primary role in promoting the effectiveness of these devices.

Health-Care Utilization and Outcomes with 10 kHz Spinal Cord Stimulation for Chronic Refractory Pain

Background

Chronic pain is a common condition associated with decreased quality of life and increased health-care costs. Opioid analgesics are routinely used to treat chronic pain despite limited evidence of long-term efficacy. Spinal cord stimulation at a frequency of 10 kilohertz (10kHz-SCS) has been shown to be effective for treating chronic pain.

Objective

This study was conducted to evaluate the effects of 10kHz-SCS on patients’ pain intensity, volume of pain interventions, and opioid intake in a real-world setting.

Study Design

This study was a retrospective review of patient data.

Setting

The study was conducted at a single, community-based clinic.

Methods

Outcomes including pain relief, quality of life, opioid intake, and rate of health-care usage were evaluated using data from patients who were implanted with a 10kHz-SCS device to treat chronic pain. These outcomes were then compared for the pre- and post-implant periods.

Results

A total of 47 patients with a mean follow-up duration of 15.6 ± 6.2 months were included in this analysis. Mean pain relief was 73 ± 22% and 89% were responders at the final follow-up visit. The rate of medical interventions fell from 3.48±3.05 per year before starting 10kHz-SCS to 0.49±1.16 per year afterward (P < 0.001). Of 30 patients with available opioid consumption data, 89% maintained or decreased their intake after implant.

Conclusion

Retrospective data from a single center, with minimal exclusion criteria shows clinically significant pain relief with 10kHz-SCS, accompanied by significant indirect benefits including stable or reduced opioid use and reduced interventional procedures.

Percutaneous Spinal Cord Stimulation Lead Placement Under Deep Sedation and General Anesthesia

INTRODUCTION

Spinal cord stimulation (SCS) is a commonly utilized therapy for the treatment of neuropathic pain conditions. The Neurostimulation Appropriateness Consensus Committee (NACC) has recommended that the placement of percutaneous SCS leads be performed in an awake patient capable of providing feedback. It is not currently known how commonly this recommendation is adhered to by physicians in clinical practice. This article presents the findings of a survey designed to answer this important question.

METHODS

We conducted a survey of the active membership of the American Society of Regional Anesthesia and Pain Medicine (ASRA) and the Spine Intervention Society (SIS) regarding practice patterns with SCS therapy. We analyzed the percent of respondents who indicated that they use deep sedation and general anesthesia during SCS placement as well as any reported complications.

RESULTS

Many practitioners frequently utilize deep sedation as well as general anesthesia when performing SCS implants. Our findings demonstrate that 77% of physicians reported that they utilize deep sedation for permanent SCS implants at times, and 45% of physicians reported the use of general anesthesia for 10 kHz implants. Additionally, 94% of physicians reported that they have never had a complication related to the use of general anesthesia for a spinal cord stimulator placement.

CONCLUSIONS

This survey provides initial data on SCS practices among a large cohort of clinicians who utilize SCS. SCS lead placement under deep sedation and general anesthesia appears to be common practice for many physicians who perform implants. This survey should stimulate further research on this topic, given that the current safety guidelines and the rate of physicians reporting the use of deep sedation and general anesthesia for spinal cord stimulator placement remain at odds.

Updates on the Role of Spinal Cord Stimulation in the Management of Non-Surgical Chronic Lower Back Pain

Studies have shown that spinal cord stimulation (SCS) therapy is effective in the management of chronic low back pain. It plays a role by minimizing the intensity of chronic pain, improving the quality of life index, reducing the intake of narcotic analgesics, and increasing the functional improvement in the working environment. However, spinal cord stimulation therapy is not universal because of the complications in the procedure itself, the invasive nature of the treatment, and cost-effectiveness. Therefore, the proper selection of the patients is necessary to get the maximum benefit from the treatment. The study's main objective is to determine the role of spinal cord stimulation in treating non-surgical patients with chronic low back pain. The article will review the mechanism, outcomes, efficacy, predisposing factors in the success and failure of the treatment and indications, contraindications, and selection of patients undergoing spinal cord stimulation therapy. A manual search of the literature was done using databases like Google Scholar and PubMed using the keywords: spinal cord, stimulation, chronic, and low back pain. A total of 37 articles were included in the study after considering the inclusion and exclusion criteria. Spinal cord stimulation therapy effectively treats refractory lower back pain, considering the technology and mechanism of action. The authors conclude that spinal cord stimulation therapy can be used to manage chronic low back pain, other neuropathic pain, and ischemic pain when other standard treatment methods have failed and the pain persisted for more than six months.

Antibiotics for Spinal Cord Stimulation Trials and Implants: A Survey Analysis of Practice Patterns

Background

Spinal cord stimulation (SCS) is an established treatment modality for neuropathic pain. Published guidelines exist to aid physicians in proper antibiotic use during and after spinal cord stimulation trials and implants. In this brief review, we present and analyze the current antibiotic practice patterns of clinicians.

Methods

The study protocol was reviewed and granted an exemption by an Institutional Review Board. The survey queried practice parameters in regards to spinal cord stimulation therapy. The American Society of Regional Anesthesia and Pain Medicine (ASRA) and Society of Interventional Spine (SIS) distributed the survey to their active members by emails with a web link to the survey.

Results

Our results indicate that 82% and 69% of physicians do not utilize nasal swabs for methicillin-sensitive Staphylococcus aureus (MSSA) or methicillin-resistant Staphylococcus aureus (MRSA), respectively, prior to SCS trial and implantation. During trials, 47% providers administer a single dose of antibiotics, 35% administer antibiotics for the duration of the trial, and 17% do not administer antibiotics. During implantation, 44% of physicians administer a single dose during the procedure, 11% administer antibiotics up to 24 hours, 24% administer antibiotics between 3-5 days, 14% administer antibiotics for more than 5 days, and 4% do not administer antibiotics.

Conclusions

Our study suggests a portion of pain physicians do not adhere to the Neuromodulation Appropriateness Consensus Committee (NACC) guidelines in regards to antibiotic administration for SCS trial and implantation. Further analysis and surveys would allow insight into common practices. More information and education would be beneficial to optimize peri-procedure antibiotic use to reduce infection risk and decrease antimicrobial resistance.

Effectiveness of high dose spinal cord stimulation for non-surgical intractable lumbar radiculopathy - HIDENS Study

OBJECTIVES

Spinal cord stimulation (SCS) is being increasingly used in non-surgical intractable low back pain. This study was designed to evaluate the efficacy of high-dose (HD) SCS utilizing sub-perception stimulation with higher frequency and pulse width in non-surgical predominant low-back pain population at 12 months.

MATERIALS AND METHODS

A total of 20 patients were recruited (280 screened between March 2017 and July 2018) to undergo percutaneous fluoroscopic-guided SCS (Medtronic 8 contact standard leads and Restore^R IPG), with T8 and T9 midline anatomical parallel placement. Sixteen patients completed 12 months follow-up (500 Hz frequency, 500 μs pulse width, and 25% pulse density). Differences in patients' clinical outcome (NRS back, NRS leg, ODI, PGIC, and PSQ) and medication usage (MQS) at 1, 3, and 12 months from the baseline were assessed using non-parametric Wilcoxon paired test.

RESULTS

The mean NRS scores for back pain (baseline 7.53) improved significantly at 1, 3, and 12 months; 2.78 (p < 0.001), 4.45 (p = 0.002), and 3.85 (p = 0.002), respectively. The mean NRS score for leg pain (baseline 6.09) improved significantly at 1 and 3 months; 1.86 (p < 0.001) and 3.13 (p = 0.010), respectively. Mean NRS for leg pain at 12 months was 3.85 (p = 0.057). ODI and sleep demonstrated significant improvement as there was consistent improvement in medication particularly opioid usage (MQS) at 12 months.

CONCLUSIONS

This study demonstrates that anatomical placement of leads with sub-perception HD stimulation could provide effective pain relief in patients who are not candidates for spinal surgery.

Systematic Literature Review of Spinal Cord Stimulation in Patients With Chronic Back Pain Without Prior Spine Surgery

OBJECTIVE

Low back pain is the leading cause of disability worldwide and one of the most common reasons for seeking healthcare. Despite numerous care strategies, patients with low back pain continue to exhibit poor outcomes. Spinal cord stimulation (SCS) is an evidence-based therapeutic modality for patients with failed back surgery syndrome. For patients without a surgical lesion or history, minimally invasive interventions that provide long-term reduction of chronic back pain are needed. Therefore, we conducted a systematic review of the evidence on SCS therapy in patients with chronic back pain who have not undergone spinal surgery.

MATERIALS AND METHODS

A systematic literature search was performed to identify studies reporting outcomes for SCS in chronic back pain patients (with or without secondary radicular leg pain) without prior surgery using date limits from database inception to February 2021. Study results were analyzed and described qualitatively.

RESULTS

A total of ten primary studies (16 publications) were included. The included studies consistently demonstrated favorable outcomes in terms of pain reduction and functional improvement following SCS therapy. Improvements also occurred in quality of life scores; however, not all studies reported statistically significant findings. Additionally, the studies reported that SCS resulted in high patient satisfaction, reductions in opioid use, and an acceptable safety profile, although these data were more limited.

CONCLUSION

Findings suggest that SCS is a promising, safe, minimally invasive, and reversible alternative option for managing chronic back pain in patients who have not undergone spinal surgery.

High-frequency 10 kHz Spinal Cord Stimulation for Chronic Back and Leg Pain: Cost-consequence and Cost-effectiveness Analyses

OBJECTIVES

There is good evidence that spinal cord stimulation (SCS) is effective for reducing chronic back and leg pain (CBLP). SENZA randomized controlled trial showed high-frequency (10 kHz) stimulation (10 kHz-SCS) is clinically superior to traditional low-frequency SCS (LF-SCS).Undertake cost-consequence and cost-effectiveness analysis of 10 kHz-SCS compared with LF-SCS.

METHODS

A probabilistic decision tree and Markov decision analytic model was used to synthesize data on CBLP outcomes and costs over a 15-year time horizon from a UK National Health Service perspective using data from the SENZA randomized controlled trial and other publications. Results are expressed as incremental cost per quality-adjusted life year (QALY) in 2016 Pounds Sterling.

RESULTS

10 kHz-SCS is cost-saving and cost-effective compared with LF-SCS, with mean cost-savings of £7170 (95% confidence interval: £6767-£7573) and £3552 (95% confidence interval: £3313-£3792) per patient compared with nonrechargeable and rechargeable LF-SCS devices, respectively. 10 kHz-SCS has a 95% likelihood of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY. Our findings were robust across a wide range of sensitivity analyses.

CONCLUSIONS

There is a strong economic case for choosing 10 kHz-SCS over LF-SCS for CBLP. Furthermore, 10 kHz-SCS has clinical advantages not captured in our analysis, including shorter, and more predictable procedure times.

Ten kHz spinal cord stimulation for the treatment of chronic peripheral polyneuropathy: 12-Month results from prospective open-label pilot study

BACKGROUND

The goal of this study was to demonstrate that the paresthesia-independent 10 kHz spinal cord stimulation (SCS) can provide long-term pain relief in patients with peripheral polyneuropathy (PPN). Clinically diagnosed subjects with PPN refractory to conventional medical management were enrolled in this prospective, multicenter study between November 2015 and August 2016, after institutional review board approval and patient informed consent were obtained.

METHODS

Subjects underwent trial stimulation utilizing 2 epidural leads, and if successful, were implanted with a permanent 10 kHz SCS system and followed up for 12 months post-implant. Outcome measures included adverse events, pain, neurological assessments, disability, function, quality of life, pain interference, sleep, satisfaction, and global impression of change. Data are presented as descriptive statistics. Permanent implant population results are reported as mean ± standard error.

RESULTS

Twenty-one of the 26 trialed subjects had a successful trial and 18 received a permanent implant. All subjects had the leads placed anatomically without the need for paresthesia. Subjects experienced significant and sustained pain relief (at least 65% at all timepoints) whereas physicians noted improvements in neurological function. Significant improvements in disability, function, sleep, sensory, and affective dimensions of pain were reported at all timepoints. All adverse events were resolved without sequelae.

CONCLUSION

Findings from this study suggest that 10 kHz SCS may provide sustained pain relief and disability improvements in patients suffering from PPN.

Management of Chronic and Neuropathic Pain with 10 kHz Spinal Cord Stimulation Technology: Summary of Findings from Preclinical and Clinical Studies

Since the inception of spinal cord stimulation (SCS) in 1967, the technology has evolved dramatically with important advancements in waveforms and frequencies. One such advancement is Nevro’s Senza^® SCS System for HF10, which received Food and Drug and Administration (FDA) approval in 2015. Low-frequency SCS works by activating large-diameter Aβ fibers in the lateral discriminatory pathway (pain location, intensity, quality) at the dorsal column (DC), creating paresthesia-based stimulation at lower-frequencies (30–120 Hz), high-amplitude (3.5–8.5 mA), and longer-duration/pulse-width (100–500 μs). In contrast, high-frequency 10 kHz SCS works with a proposed different mechanism of action that is paresthesia-free with programming at a frequency of 10,000 Hz, low amplitude (1–5 mA), and short-duration/pulse-width (30 μS). This stimulation pattern selectively activates inhibitory interneurons in the dorsal horn (DH) at low stimulation intensities, which do not activate the dorsal column fibers. This ostensibly leads to suppression of hyperexcitable wide dynamic range neurons (WDR), which are sensitized and hyperactive in chronic pain states. It has also been reported to act on the medial pathway (drives attention and pain perception), in addition to the lateral pathways. Other theories include a reversible depolarization blockade, desynchronization of neural signals, membrane integration, glial–neuronal interaction, and induced temporal summation. The body of clinical evidence regarding 10 kHz SCS treatment for chronic back pain and neuropathic pain continues to grow. There is high-quality evidence supporting its use in patients with persistent back and radicular pain, particularly after spinal surgery. High-frequency 10 kHz SCS studies have demonstrated robust statistically and clinically significant superiority in pain control, compared to paresthesia-based SCS, supported by level I clinical evidence. Yet, as the field continues to grow with the technological advancements of multiple waveforms and programming stimulation algorithms, we encourage further research to focus on the ability to modulate pain with precision and efficacy, as the field of neuromodulation continues to adapt to the modern healthcare era.

Amelioration of lower limb pain and foot drop with 10 kHz spinal cord stimulation: A case series

There are limited treatment options for patients with foot drop and associated lower back and/or leg pain. We present a case series of three patients who received permanent implantation of 10 kHz spinal cord stimulation (10 kHz SCS) devices. Following treatment, all patients reported sustained improvements in lower back and leg pain, foot mechanics and function which resulted in increased mobility and cessation of opioid use for pain management. Patients were followed up for approximately four years. Treatment with 10 kHz SCS may be a promising alternative to other interventional procedures commonly used for these patients.

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.

One-Year Results of Prospective Research Study Using 10 kHz Spinal Cord Stimulation in Persistent Nonoperated Low Back Pain of Neuropathic Origin: Maiden Back Study

PURPOSE

Spinal cord stimulation (SCS) is a recommended treatment for chronic neuropathic pain. Persistent nonoperative low back pain of neuropathic origin has profound negative impacts on patient's lives. This prospective, open label, research study aimed to explore the use of SCS in patients with associated features of central sensitisation such as allodynia and hyperalgesia.

MATERIALS AND METHODS

Twenty-one patients with back pain and hyperalgesia or allodynia who had not had prior spinal surgery underwent a SCS trial followed by full implantation. SCS comprised administering electrical impulses epidurally at a frequency of 10 kHz and pulse width of 30 μsec. Patients attended follow-up visits after 6 and 12 months of SCS. Repeated measure ANOVAs/Friedman tests explored change after 6 and 12 months of 10 kHz SCS. Independent sample t-tests/Mann-Whitney U tests examined differences in response after 12 months of 10 kHz SCS.

RESULTS

Back and leg pain, quality of life (QoL), pain-related disability, and morphine equivalence significantly improved compared with baseline following 6 and 12 months of 10 kHz SCS. There were no increases in the consumption of opioids, amitriptyline, gabapentin or pregabalin in any patient. After 12 months of treatment, 52% encountered ≥50% improvement in back pain, 44% achieved remission (0-3 cm back pain VAS), 40% reported ODI scores between 0 and 40 and 60% experienced a reduction of at least 10 ODI points. Patients reporting ≥10-point improvement in ODI had significantly longer pain history durations and experienced significantly greater improvements in back pain, leg pain and QoL than those reporting <10-point improvement in ODI.

CONCLUSION

The 10 kHz SCS improved back and leg pain, QoL, pain-related disability and medication consumption in patients with nonoperative back pain of neuropathic origin. With further research incorporating a sham control arm, the efficacy of 10 kHz SCS in this patient cohort will become more established.

Spinal Cord Stimulation to Treat Low Back Pain in Patients With and Without Previous Spine Surgery

OBJECTIVES

Little is known about the effects of spinal cord stimulation (SCS) on chronic low back pain (CLBP) patients with no history of previous spine surgery. Using our prospectively collected database, we evaluate improvements in patients with and without previous spine surgery one-year post SCS implantation.

MATERIALS AND METHODS

Subjects completed outcome metrics pre-operatively and one-year post-implantation including Numeric Rating Scale (NRS), McGill Pain Questionnaire (MPQ), Oswestry Disability Index (ODI), Beck's Depression Inventory (BDI), and Pain Catastrophizing Scale (PCS).

RESULTS

We enrolled 134 patients; 82 patients had previous spine surgery and 52 patients did not. At one-year post-SCS implantation, patients with previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, MPQ affective, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.03, p = 0.01, p = 0.02, p < 0.001, p = 0.05, p < 0.001, p = 0.017, respectively). Likewise, patients without previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.008, p < 0.001, p < 0.001, respectively). Patients without previous spine surgery showed greater improvements for average pain PCS helplessness (p = 0.01).

CONCLUSIONS

Patients with and without previous spine surgery showed similar improvements in pain intensity, pain quality, feelings of rumination and magnification, functional disability, and depression severity. SCS can improve CLBP regardless of whether patients have had previous spine surgery.

Retrospective Assessment of Salvage to 10 kHz Spinal Cord Stimulation (SCS) in Patients Who Failed Traditional SCS Therapy: RESCUE Study

Background and Objectives

A randomized clinical trial demonstrated that 10 kHz SCS (10kHz-SCS) therapy is superior to traditional low-frequency SCS (LF-SCS) at 12- and 24-month clinical follow-ups and led to Food and Drug Administration (FDA) approval of the therapy. The results of the study led our practices to trial 10kHz-SCS in patients who had not maintained pain relief with LF-SCS therapy. Here, we report a large set of data from two clinical sites to assess if 10kHz-SCS is an effective salvage modality when LF-SCS fails.

Methods

We conducted a retrospective chart review of 120 patients across two clinical sites who had LF-SCS implants and were salvaged with 10kHz-SCS.

Results

Data were analyzed from 105 patients between 28 and 90 years old (median 60) with chronic pain for 13.6 years. The mean duration of LF-SCS therapy was 4.66±3.9 years. The average Visual Analog Scale (VAS) decreased from 8.30±1.4 (median of 8) cm to 3.32±2.0 (median of 3) cm at 12 months and 3.36±2.0 (median of 3) cm at the most recent clinic visit (p<0.001) following salvage therapy. Pain relief of 50% or more was obtained in 85 out of 105 (81%) patients. Opioid usage decreased from 60.3±77.1 mg to 32.1±44.0 mg MSO4 equivalents (p = 0.001) at 12 months after salvage therapy.

Conclusion

Eighty-one percent of patient cases reviewed, where LF-SCS had failed, achieved >50% pain relief with 10kHz-SCS, and almost all exhibited some clinical improvement. Therefore, 10kHz-SCS should be considered an appropriate option to rescue failed LF-SCS.

Explant rates of electrical neuromodulation devices in 1177 patients in a single center over an 11-year period

Introduction

The publication of explant rates has established risk factors and a definitive objective outcome of failure for spinal cord stimulation (SCS) treating neuropathic pain. We present a UK study analyzing explants of electrical neuromodulation devices for different conditions over 11 years in a single center specializing in neuromodulation.

Methods

A retrospective analysis was performed using a departmental database between 2008 and 2019. Explants were analyzed according to condition, mode of stimulation and other demographics using logistic regression and Kaplan-Meier graphs with log-rank (Mantel-Cox) test.

Results

Out of a total of 1177 patients, the explant rate was 17.8% at 5 years and 25.2% at 10 years. Loss of efficacy was the most frequent reason for explant 119/181 (65%). Multivariant regression analysis indicated patients with back pain without prior surgery had a reduced risk of explant (p=0.03). Patients with SCS systems that had 10 kHz, options of multiple waveforms, and rechargeable batteries also had a decreased risk of explant (p<0.001). None of these findings were confirmed when comparing Kaplan-Meier graphs, however. Contrary to other studies, we found gender and age were not independent variables for explant.

Conclusion

These data contribute to a growing list of explant data in the scientific literature and give indications of what factors contribute to long-term utilization of electrical neuromodulation devices.

10 kHz spinal cord stimulation for the treatment of chronic back and/or leg pain: Summary of clinical studies

Chronic pain has a major impact on sufferers and their families. The associated health care costs are substantial. In the context of increasing prevalence, effective treatment options are ever more important. 10 kHz spinal cord stimulation has been shown to effectively provide pain relief, aid in opioid reduction, and improve quality of life in patients with chronic intractable pain. The present review aims to summarize the clinical evidence related to the use of 10 kHz SCS in chronic back and/or leg pain. We searched the PubMed database between 2009 and 2 June 2020 for articles reporting clinical studies that included at least 10 human subjects permanently treated with a 10 kHz SCS system (Senza^® system) for chronic back and/or leg pain for a minimum of 3 months. A randomized controlled trial (SENZA-RCT), as well as several prospective and retrospective studies, reported clinical outcomes in subjects with chronic back and leg pain treated with 10 kHz SCS. A high proportion of subjects (60%–80%) reported long-term response to therapy. Pain relief was provided without paresthesia. Other studies showed promising pain relief outcomes in subjects with back pain ineligible for spinal surgery, neuropathic limb pain, and in those with previously failed traditional low-frequency SCS. Most studies reported improved quality of life metrics and/or reduced opioid intake. Level 1 evidence has already been established for the use of 10 kHz SCS in treating chronic back and leg pain, corroborated by real-world, clinical experience. Exploratory studies also show the potential of the therapy in other refractory pain syndromes, although larger studies are desired to validate their findings. Overall, the literature suggests that 10 kHz SCS provides long-term pain relief in a high proportion of patients, along with improved quality of life and reduced opioid consumption.

10-kHz Spinal Cord Stimulation for Chronic Postsurgical Pain: Results From a 12-Month Prospective, Multicenter Study

Background

Chronic postsurgical pain (CPSP) can be caused by peripheral nerve injury (PNI) resulting from surgical procedures and has a significant neuropathic component. This prospective, single‐arm study was conducted to document the effectiveness of 10‐kHz spinal cord stimulation (10‐kHz SCS) as a treatment for patients with CPSP.

Methods

Subjects with CPSP who were refractory to conventional medical interventions and reported pain scores of ≥5 cm on a 10‐cm VAS underwent trial stimulations lasting up to 14 days. Epidural leads were implanted at locations appropriate for the primary area of pain, and trials resulting in ≥40% pain relief were considered successful. Subjects with successful trials underwent implantation with a permanent 10‐kHz SCS system and were followed for 12 months after implantation.

Results

Of the 34 subjects who underwent trial stimulation, 1 was withdrawn early and 29 (87.9%) had a successful trial and received a permanent implant. After 12 months of treatment, the mean VAS score decreased by 6.5 cm, the response rate was 88.0% (22/25), and 18 subjects (62.1%) were remitters with VAS scores sustained at ≤3.0 cm. Scores for all components of the short‐form McGill Pain Questionnaire 2 were significantly reduced, including affective descriptors of pain. Pain catastrophizing and vigilance, patient function, physical and mental well‐being, and sleep quality all improved over the course of the study. No neurologic deficits reported in the study.

Conclusions

10‐kHz SCS is effective and tolerated in patients with CPSP, and further study of its clinical application in this population is warranted.