To Trial or Not to Trial Before Spinal Cord Stimulation for Chronic Neuropathic Pain: The Patients' View From the TRIAL-STIM Randomized Controlled Trial

Real World Characterization of Chronic Pain, Success Rates and Implant Rates: Evidence from a Digital Health Platform of Patients Undergoing Spinal Cord Stimulation Evaluations

Spinal cord stimulation is an effective treatment for those experiencing chronic back and leg pain but requires a temporary evaluation period (SCSeval) before permanent implantation. We present real-world data from 7,000 patients who underwent SCSeval while utilizing a mobile digital health platform for education, feedback, and outcomes collection during their surgical journey. We analyzed preoperative patient demographics, characterized patient pain profiles using the patient-reported outcomes measurement information system-29 surveys, and calculated the rates of conversion from temporary to permanent spinal cord stimulation (SCS) implantation. Between August 1, 2021, and March 2, 2023, 7,000 patients (mean age 59.1, 59.6% female) underwent SCSeval procedures while utilizing a mobile application. Patients commonly experienced aching, sharp, stabbing, tingling, numb, and burning pain. Patients had tried multiple prior therapies and wanted to reduce their use of opioids and pain medications. Overall, 90.1% of the patients had a successful SCSeval, and 80.4% of those converted to permanent implant, with the highest rates among those who underwent SCSeval in a hospital setting. There was a significant improvement in all domains of pain as evaluated by pre and postoperative patient-reported outcomes measurement information system-29 surveys. This study supports the use of digital health technology as part of the SCS journey to improve the patient experience and allow for robust patient-reported outcomes collection. The overall rate of SCSeval to permanent SCS in our study of 72.4% was higher than national rates of 64%, suggesting that an app may allow clinicians to better quantify changes in chronic pain and provide more insight into choosing to implant SCS permanently. PERSPECTIVE: This article presents real-world evidence from a digital health platform for therapy education and outcomes collection from patients undergoing spinal cord stimulation evaluation procedures. Such tools could allow for better pain characterization and allow for more nuanced tracking of patient outcomes among those with chronic pain.

International Society for the Advancement of Spine Surgery Statement: Restorative Neurostimulation for Chronic Mechanical Low Back Pain Resulting From Neuromuscular Instability

This International Society for the Advancement of Spine Surgery statement has been generated to respond to growing requests for background, supporting literature and evidence, and proper coding for restorative neurostimulation for chronic low back pain. Chronic low back pain describes the diverse experience of a significant proportion of the population. Conservative management of these patients remains the predominant care pathway, but for many patients, symptom relief is poor. The application of new techniques in patients who have exhausted traditional care paradigms should be undertaken with a detailed understanding of the pathology being treated, the mechanisms involved, and the data supporting efficacy. This statement on restorative neurostimulation places this technology in the context of the current understanding of the etiology of mechanical low back pain and the currently available evidence for this technique. In an appropriately selected cohort with a specific subset of chronic low back pain symptoms, this technique may provide benefit to payers and patients.

Cost-utility Analysis of Evoke Closed-loop Spinal Cord Stimulation for Chronic Back and Leg Pain

OBJECTIVES

The effectiveness of Evoke closed-loop spinal cord stimulation (CL-SCS), a novel modality of neurostimulation, has been demonstrated in a randomized controlled trial (RCT). The objective of this cost-utility analysis was to develop a de novo economic model to estimate the cost-effectiveness of Evoke CL-SCS when compared with open-loop SCS (OL-SCS) for the management of chronic back and leg pain.

METHODS

A decision tree followed by a Markov model was used to estimate the costs and outcomes of Evoke CL-SCS versus OL-SCS over a 15-year time horizon from the UK National Health Service perspective. A "high-responder" health state was included to reflect improved levels of SCS pain reduction recently reported. Results are expressed as incremental cost per quality-adjusted life year (QALY). Deterministic and probabilistic sensitivity analysis (PSA) was conducted to assess uncertainty in the model inputs.

RESULTS

Evoke CL-SCS was estimated to be the dominant treatment strategy at ~5 years postimplant (ie, it generates more QALYs while cost saving compared with OL-SCS). Probabilistic sensitivity analysis showed that Evoke CL-SCS has a 92% likelihood of being cost-effective at a willingness to pay threshold of £20,000/QALY. Results were robust across a wide range of scenario and sensitivity analyses.

DISCUSSION

The results indicate a strong economic case for the use of Evoke CL-SCS in the management of chronic back and leg pain with or without prior spinal surgery with dominance observed at ~5 years.

The Invasive Management of Pain: Diagnosis and New Treatment Options

Both the diagnosis and treatment of pain are evolving, especially in interventional approaches. Diagnosis of low back pain combines old and new methodologies, in particular, it involves an expanded role for ultrasound. While low back pain is a common complaint, there are many etiologies to the condition which must be explored before a final diagnosis can be made and treatment planned. Tumors and infections are rarely involved in low back pain but should be ruled out in the initial phase itself since failing to address them early can have devastating consequences. Some invasive treatments seem promising in the management of low back pain. Treating musculoskeletal pain with regenerative medicine, such as platelet-rich plasma, holds great promise. Autologous blood products are safe and may help stimulate the body's own responses for regeneration. The so-called "orthobiologics" play a role in sports medicine and the treatment of musculoskeletal pain. Neuromodulation, especially spinal cord stimulation, is undergoing a renaissance with new waveforms, devices, and a greater albeit incomplete understanding of its mechanisms of action. Spinal cord stimulation is not a first-line therapy and not all patients or all back problems respond to this treatment. Nevertheless, the therapy can be safe, effective, and cost-effective with appropriate patient selection. Radiofrequency ablation of nerves in the form of neurotomy can be effective in reducing the pain of osteoarthritis. These procedures, including the newer cooled radiofrequency neurotomy, can restore function, reduce pain, and may potentially have an opioid-sparing effect. Technical expertise in nerve and anatomy is needed for the use of this technique. This review article aims to provide updated information on some invasive intervention techniques in pain management.

Evidence-based consensus guidelines on patient selection and trial stimulation for spinal cord stimulation therapy for chronic non-cancer pain

Spinal cord stimulation (SCS) has demonstrated effectiveness for neuropathic pain. Unfortunately, some patients report inadequate long-term pain relief. Patient selection is emphasized for this therapy; however, the prognostic capabilities and deployment strategies of existing selection techniques, including an SCS trial, have been questioned. After approval by the Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, a steering committee was formed to develop evidence-based guidelines for patient selection and the role of an SCS trial. Representatives of professional organizations with clinical expertize were invited to participate as committee members. A comprehensive literature review was carried out by the steering committee, and the results organized into narrative reports, which were circulated to all the committee members. Individual statements and recommendations within each of seven sections were formulated by the steering committee and circulated to members for voting. We used a modified Delphi method wherein drafts were circulated to each member in a blinded fashion for voting. Comments were incorporated in the subsequent revisions, which were recirculated for voting to achieve consensus. Seven sections with a total of 39 recommendations were approved with 100% consensus from all the members. Sections included definitions and terminology of SCS trial; benefits of SCS trial; screening for psychosocial characteristics; patient perceptions on SCS therapy and the use of trial; other patient predictors of SCS therapy; conduct of SCS trials; and evaluation of SCS trials including minimum criteria for success. Recommendations included that SCS trial should be performed before a definitive SCS implant except in anginal pain (grade B). All patients must be screened with an objective validated instrument for psychosocial factors, and this must include depression (grade B). Despite some limitations, a trial helps patient selection and provides patients with an opportunity to experience the therapy. These recommendations are expected to guide practicing physicians and other stakeholders and should not be mistaken as practice standards. Physicians should continue to make their best judgment based on individual patient considerations and preferences.

Spinal Cord Stimulation for Failed Back Surgery Syndrome: to Trial or Not to Trial?

Spinal cord stimulation (SCS) is a recommended therapy to treat failed back surgery syndrome (FBSS). A trial period is practised to enhance patient selection. However, its fundamental evidence is limited, especially concerning long-term benefit and therapy safety. We compared the long-term (5.3 ± 4.0 years) clinical outcome and therapy safety of a trialled and non-trialled implantation strategy, including multidimensional variables and pain intensity fluctuations over time. A multi-centre cohort analysis was performed in two comparable groups of FBSS patients. Regarding eligibility, patients had to be treated with SCS for at least three months. While the Trial group comprised patients who underwent an SCS implantation after a successful trial, the No-Trial group encompassed patients who underwent complete implantation within one session. The primary outcome measures were pain intensity scores and complications. The Trial and No-Trial groups consisted of 194 and 376 patients(N=570), respectively. A statistically but not clinically significant difference in pain intensity (p=0.003; effect=0.506 (0.172-0.839)) was found in favour of the Trial group. No interaction between a time dependency effect and pain intensity was noted. Whereas trialled SCS patients were more likely to cease opioid usage (p=0.003; OR=0.509 (0.326-0.792)), patients in the No-Trial group endured fewer infections (p=0.006; proportion difference=0.43 (0.007-0.083)). Although the clinical relevance of our findings should be proven in future studies, this long-term real-world data study indicates that patient-centered assessments on whether an SCS trial should be performed have to be investigated. According to the current ambiguous evidence, SCS trials should be considered on a case-by-case basis. PERSPECTIVE: The currently available comparative evidence, together with our results, remains ambiguous on which SCS implantation strategy might be deemed superior. An SCS trial should be considered on a case-by-case basis, for which further investigation of its clinical utility in certain patient populations or character traits is warranted.

Does a Screening Trial for Spinal Cord Stimulation in Patients With Chronic Pain of Neuropathic Origin Have Clinical Utility (TRIAL-STIM)? 36-Month Results From a Randomized Controlled Trial

BACKGROUND

Screening trials before full implantation of a spinal cord stimulation device are recommended by clinical guidelines and regulators, although there is limited evidence for their use. The TRIAL-STIM study showed that a screening trial strategy does not provide superior patient pain outcome at 6-month follow-up compared with not doing a screening trial and that it was not cost-effective.

OBJECTIVE

To report the long-term follow-up results of the TRIAL-STIM study.

METHODS

The primary outcome of this pragmatic randomized controlled trial was pain intensity as measured on a numerical rating scale (NRS) and secondary outcomes were the proportion of patients achieving at least 50% and 30% pain relief at 6 months, health-related quality of life, and complication rates.

RESULTS

Thirty patients allocated to the "Trial Group" (TG) and 36 patients allocated to the "No Trial Group" (NTG) completed outcome assessment at 36-month follow-up. Although there was a reduction in NRS pain and improvements in utility scores from baseline to 36 months in both groups, there was no difference in the primary outcome of pain intensity NRS between TG and NTG (adjusted mean difference: -0.60, 95% CI: -1.83 to 0.63), EuroQol-5 Dimension utility values (adjusted mean difference: -0.02, 95% CI: -0.13 to 0.10), or proportion of pain responders (33% TG vs 31% NTG). No differences were observed between the groups for the likelihood of spinal cord stimulation device explant or reporting an adverse advent up to 36-month follow-up.

CONCLUSION

The long-term results show no patient outcome benefit in undertaking an SCS screening trial.

Systematic Review and Network Meta-analysis of Neurostimulation for Painful Diabetic Neuropathy

BACKGROUND

Different waveforms of spinal cord stimulation (SCS) have now been evaluated for the management of painful diabetic neuropathy (PDN). However, no direct or indirect comparison between SCS waveforms has been performed to date.

PURPOSE

To conduct a systematic review and network meta-analysis to evaluate the effectiveness of SCS for PDN.

DATA SOURCES

MEDLINE, CENTRAL, Embase, and WikiStim were searched from inception until December 2021.

STUDY SELECTION

Randomized controlled trials (RCTs) of SCS for PDN were included.

DATA EXTRACTION

Pain intensity, proportion of patients achieving at least a 50% reduction in pain intensity, and health-related quality of life (HRQoL) data were extracted.

DATA SYNTHESIS

Significant reductions in pain intensity were observed for low-frequency SCS (LF-SCS) (mean difference [MD] -3.13 [95% CI -4.19 to -2.08], moderate certainty) and high-frequency SCS (HF-SCS) (MD -5.20 [95% CI -5.77 to -4.63], moderate certainty) compared with conventional medical management (CMM) alone. There was a significantly greater reduction in pain intensity on HF-SCS compared with LF-SCS (MD -2.07 [95% CI -3.26 to -0.87], moderate certainty). Significant differences were observed for LF-SCS and HF-SCS compared with CMM for the outcomes proportion of patients with at least 50% pain reduction and HRQoL (very low to moderate certainty). No significant differences were observed between LF-SCS and HF-SCS (very low to moderate certainty).

LIMITATIONS

Limited number of RCTs and no head-to-head RCTs conducted.

CONCLUSIONS

Our findings confirm the pain relief and HRQoL benefits of the addition of SCS to CMM for patients with PDN. However, in the absence of head-to-head RCT evidence, the relative benefits of HF-SCS compared with LF-SCS for patients with PDN remain uncertain.

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

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

Patient Selection for Spinal Cord Stimulation in Treatment of Pain: Sequential Decision-Making Model - A Narrative Review

Despite the well-known efficacy of spinal cord stimulation (SCS) in chronic pain management, patient selection in clinical practice remains challenging. The aim of this review is to provide an overview of the factors that can influence the process of patient selection for SCS treatment. A sequential decision-making model is presented within a tier system that operates in clinical practice. The first level incorporates the underlying disease as a primary indication for SCS, country-related reimbursement rules, and SCS screening-trial criteria in combination with underlying psychological factors as initial selection criteria in evaluating patient eligibility for SCS. The second tier is aligned with the individualized approach within precision pain medicine, whereby individual goals and expectations and the potential need for preoperative optimizations are emphasized. Additionally, this tier relies on results from prediction models to provide an estimate of the efficacy of SCS in the long term. In the third tier, selection bias, MRI compatibility, and ethical beliefs are included, together with recent technological innovations, superiority of specific stimulation paradigms, and new feedback systems that could indirectly influence the decision-making of the physician. Both patients and physicians should be aware of the different aspects that influence patient selection in relation to SCS for pain management to make an independent decision on whether or not to initiate a treatment trajectory with SCS.

Improved User Engagement and Assessment of Treatment Effectiveness in Patients Utilizing a Novel Digital Mobile Health Application During Spinal Cord Stimulation Screening Trials (Preprint)

Background

Patient outcomes and experience during a Spinal Cord Stimulation (SCS) screening trial can have a significant effect on whether to proceed with long-term, permanent implantation of an SCS device for the treatment of chronic pain. Enhancing the ability to track and assess patients during this initial trial evaluation offers the potential for improved understanding regarding the suitability of permanent device implantation as well as identification of the SCS-based neurostimulative modalities and parameters that may provide substantial analgesia in a patient-specific manner.

Objective

In this report, we aimed to describe a preliminary, real-world assessment of a new, real time tracking, smart, device-based digital app used by patients with chronic pain undergoing trial screening for SCS therapy.

Methods

This is a real-world, retrospective evaluation of 13,331 patients diagnosed with chronic pain who used the new “mySCS” mobile app during an SCS screening trial. The app design is health insurance portability and accountability act (HIPAA)-compliant and compatible with most commercially available smartphones (eg, Apple, iPhone, and Android). The app enables tracking of user-inputted health-related responses (ie, pain relief, activity level, and sleep quality) in addition to personal trial goals and a summary of overall experience during the SCS trial. A deidentified, aggregate analysis of user engagement, user-submitted responses, and overall trial success was conducted.

Results

When provided the opportunity, the percentage of users who engaged with the tracking app for ≥50% of the time during their trial was found to be 64.43% (n=8589). Among the 13,331 patients who used the app, 58.24% (n=7764) entered a trial goal. Most patients underwent SCS screening with a trial duration of at least 7 days (n=7739, 58.05%). Of those patients who undertook a 7-day SCS trial, 62.30% (n=3456) engaged the app for 4 days or more. In addition, among all who submitted descriptive responses using the app, health-related improvements were reported by 77.84% (n=10,377) of patients who reached day 3 of the screening phase assessment and by 83.04% (n=11,070) of those who reached trial completion. A trial success rate of 91% was determined for those who used the app (versus 85% success rate for nonusers).

Conclusions

Data from this initial, real-world examination of a mobile, digital-health–based tracking app (“mySCS”), as used during the SCS screening phase, demonstrate that substantial patient engagement can be achieved while also providing for the acquisition of more real time patient-outcome measures that may help facilitate improved SCS trial success.