Randomized Placebo-Controlled Trial of 60-Day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain, and Improved Function After Knee Replacement.

OBJECTIVES: Total knee arthroplasty (TKA) is an effective surgery for end-stage knee osteoarthritis, but chronic postoperative pain and reduced function affect up to 20% of patients who undergo such surgery. There are limited treatment options, but percutaneous peripheral nerve stimulation (PNS) is a promising nonopioid treatment option for chronic, persistent postoperative pain. The objective of the present study was to evaluate the effect of a 60-day percutaneous PNS treatment in a multicenter, randomized, double-blind, placebo-controlled trial for treating persistent postoperative pain after TKA. MATERIALS AND METHODS: Patients with postoperative pain after knee replacement were screened for this postmarket, institutional review board-approved, prospectively registered (NCT04341948) trial. Subjects were randomized to receive either active PNS or placebo (sham) stimulation. Subjects and a designated evaluator were blinded to group assignments. Subjects in both groups underwent ultrasound-guided placement of percutaneous fine-wire coiled leads targeting the femoral and sciatic nerves on the leg with postoperative pain. Leads were indwelling for eight weeks, and the primary efficacy outcome compared the proportion of subjects in each group reporting ≥50% reduction in average pain relative to baseline during weeks five to eight. Functional outcomes (6-minute walk test; 6MWT and Western Ontario and McMaster Universities Osteoarthritis Index) and quality of life (Patient Global Impression of Change) also were evaluated at end of treatment (EOT). RESULTS: A greater proportion of subjects in the PNS groups (60%; 12/20) than in the placebo (sham) group (24%; 5/21) responded with ≥50% pain relief relative to baseline (p = 0.028) during the primary endpoint (weeks 5-8). Subjects in the PNS group also walked a significantly greater distance at EOT than did those in the placebo (sham) group (6MWT; +47% vs -9% change from baseline; p = 0.048, n = 18 vs n = 20 completed the test, respectively). Prospective follow-up to 12 months is ongoing. CONCLUSIONS: This study provides evidence that percutaneous PNS decreases persistent pain, which leads to improved functional outcomes after TKA at EOT.

Educational Curriculum for Peripheral Nerve Stimulation Developed by the North American Neuromodulation Society.

BACKGROUND: Peripheral nerve stimulation (PNS) is an effective neuromodulation therapy for chronic neuropathic and nociceptive pain. Although the total number of PNS implantations has increased over the last decade, no curriculum exists to guide training and learning of this therapy. The goal of the North American Neuromodulation Society (NANS) education committee is to develop a series of competency-based curriculums for neuromodulation therapies. The PNS curriculum is the latest part of such series, following the curriculums for spinal cord stimulation and intrathecal drug delivery system. MATERIALS AND METHODS: A multidisciplinary task force (anesthesiology, physical medicine and rehabilitation, neurosurgery, preventive medicine and public health, and neurology) was created by the educational committee of NANS to develop a PNS curriculum in accordance with the Accreditation Council for Graduate Medical Education (ACGME) milestones. The curriculum was created based on the best available evidence and expert knowledge (from our task force members) of available PNS systems. The final PNS curriculum was approved by the NANS board. RESULTS: A PNS curriculum was developed by the task force. Milestones included professionalism, practice-based learning, interpersonal communication, medical knowledge, systems-based practice, procedural skills, and patient care. Each milestone was defined into three categories: early learner, advanced learner, and practitioner. CONCLUSIONS: This manuscript provides a PNS training curriculum developed by a multidisciplinary task force of the NANS educational committee in accordance with the milestones described by ACGME for basic learners, advanced learners, and practitioners. This curriculum will help provide a structured training and evaluation process for obtaining proficiency in PNS treatment(s).

Pulse Dosing of 10-kHz Paresthesia-Independent Spinal Cord Stimulation Provides the Same Efficacy with Substantial Reduction of Device Recharge Time.

OBJECTIVE: This study was designed to assess whether using pulse dosing (PD) (regularly cycled intermittent stimulation) of high-frequency 10-kHz spinal cord stimulation (10-kHz SCS) can reduce device recharge time while maintaining efficacy in patients with chronic intractable back pain with or without leg pain. DESIGN: Prospective, multicenter, observational study. METHODS: Patients successfully using 10-kHz SCS at 100%ON (i.e., continuously with no PD) for >3 months were consecutively enrolled. After a 1-week baseline period of documenting their pain twice daily on a 0-10 numerical rating scale (NRS) using 100%ON of their "favorite" program, all subjects were reprogrammed to 14%PD for 10-14 days. If subjects preferred 14%PD to 100%ON, they were programmed to 3%PD; otherwise, they were programmed to 50%PD. Subjects used this next program for another 10-14 days. Subjects then entered a 3-month observational period during which they were requested to use but not limited to their most preferred %PD program. Toward the end of 3 months, subjects completed a 7-day NRS diary and indicated a final %PD program preference. Study endpoints included %PD preference, mean diary NRS by %PD, and daily minutes and patterns of charging. RESULTS: Of 31 subjects completing the study, 81% preferred less than 100%ON. Among the subjects, 39% preferred 3%PD, 32% preferred 14%PD, 10% preferred 50%PD, and 19% preferred 100%ON. Average daily charge durations were 8.3 ± 3.1 minutes for 3%PD, 13.9 ± 4.9 minutes for 14%PD, 26.2 ± 7.4 minutes for 50%PD, and 43.8 ± 10.9 minutes for 100%ON. Regression modeling suggested that pain relief was weighted as more than twice as influential as charging in preference for reduced %PD. CONCLUSIONS: This prospective study suggests that 10-kHz SCS therapy with PD may be successfully used in a large majority of 10-kHz SCS responders, maintaining efficacy while reducing device charging time by nearly two thirds.

Diagnosis of Sacroiliac Joint Pain: Predictive Value of Three Diagnostic Clinical Tests.

INTRODUCTION: To date, there have been no acceptable and accurate diagnostic criteria or standards of care for the management of sacroiliac joint (SIJ) pain. Several studies have yielded different contributions of clinical presentation, history, and physical examination in the diagnosis of SIJ pain. Our goal in this study was to assess the sensitivity and specificity of the diagnostic clinical tests and their predictive value in accurately diagnosing SIJ pain. METHODOLOGY: Upon enrolling 200 eligible patients with SIJ pain as their primary diagnosis, they were re-evaluated and their verbal rating scale (VRS) pain scores and demographic data were obtained. Thereafter, three SIJ diagnostic tests were performed: the thigh thrust test, the Patrick test, and a modified version of the Gaenslen test that is referred to as the Mekhail test. Subsequently, the patients were taken to the procedure room to undergo SIJ injection, for which a confirmative result was ≥50% pain relief. The physicians performing the procedure were blinded of the results of the 3 tests performed. Results from the 3 tests were incorporated with the procedure results, from which we drew statistical and medical conclusions determining their predictive value and degree of aid to physicians in diagnosing SIJ pain. RESULTS: We found that the cumulative effect of adding simultaneous tests increased the sensitivity of the testing but decreased the specificity, which generates a powerful screening tool. The combination of the Patrick and Mekhail tests demonstrated the best accuracy, with 94% sensitivity, 17% specificity, 81% positive predictive value, and 44% negative predictive value. The Patrick test was better than other tests for differentiating patients with SIJ pain from those with non-SIJ pain. No combination yielded both significant sensitivity and specificity. Generally, the overall predictive value of any of the tests on their own or their combination did not vary significantly from the predictive value of baseline demographics, including pre-injection pain score and pain referral diagram. CONCLUSION: In conclusion, our study results were similar to those of previous investigators who found that physical examination plays a limited role in diagnosing SIJ pain. Specifically, we found that the clinical tests and/or their combinations added no significant predictive capacity compared to patients' baseline characteristics in predicting the response to diagnostic SIJ injection, albeit the combination of the Mekhail and Patrick tests yielded high sensitivity (94%), making them viable for consecutive screening, possibly reducing the unnecessary costs of diagnostic SIJ injection procedures.

Cooled radiofrequency ablation provides extended clinical utility in the management of knee osteoarthritis: 12-month results from a prospective, multi-center, randomized, cross-over trial comparing cooled radiofrequency ablation to a single hyaluronic acid injection.

BACKGROUND: Safe and effective non-surgical treatments are an important part of the knee osteoarthritis (OA) treatment algorithm. Cooled radiofrequency ablation (CRFA) and hyaluronic acid (HA) injections are two commonly used modalities to manage symptoms associated with knee OA. METHODS: A prospective 1:1 randomized study was conducted in 177 patients comparing CRFA to HA injection with follow-ups at 1, 3, 6 and 12 months. HA subjects with unsatisfactory outcomes at 6-months were allowed to crossover and receive CRFA. Knee pain (numeric rating scale = NRS), WOMAC Index (pain, stiffness and physical function), overall quality of life (global perceived effect = GPE, EQ-5D-5 L), and adverse events were measured. RESULTS: At 12-months, 65.2% of subjects in the CRFA cohort reported ≥50% pain relief from baseline. Mean NRS pain score was 2.8 ± 2.4 at 12 months (baseline 6.9 ± 0.8). Subjects in the CRFA cohort saw a 46.2% improvement in total WOMAC score at the 12-month timepoint. 64.5% of subjects in the crossover cohort reported ≥50% pain relief from baseline, with a mean NRS pain score of 3.0 ± 2.4 at 12 months (baseline 7.0 ± 1.0). After receiving CRFA, subjects in the crossover cohort had a 27.5% improvement in total WOMAC score. All subjects receiving CRFA reported significant improvement in quality of life. There were no serious adverse events related to either procedure and overall adverse event profiles were similar. CONCLUSION: A majority of subjects treated with CRFA demonstrated sustained knee pain relief for at least 12-months. Additionally, CRFA provided significant pain relief for HA subjects who crossed over 6 months after treatment. TRIAL REGISTRATION: This trial was registered on ClinicalTrials.gov, NCT03381248. Registered 27 December 2017.

Development of an Educational Curriculum for Spinal Cord Stimulation.

BACKGROUND: Spinal cord stimulators (SCSs) are used for treating chronic pain. The number of SCSs implanted each year is on the increase. The North American Neuromodulation Society (NANS) education committee aimed to develop a SCS curriculum as a tool to guide physicians at different training levels, based on the most recent evidence. MATERIAL AND METHODS: A multidisciplinary (anesthesiology, physical medicine, neurosurgery, and neurology), taskforce representing the education committee of the NANS met to develop a SCS curriculum following the Accreditation Council for Graduate Medical Education (ACGME) milestones. The task force used the best available evidence and knowledge to develop the curriculum. Once developed, the SCS curriculum was then approved by the NANS board. RESULTS: The task force developed a SCS training curriculum. Milestones included patient care and procedural skills, system-based practice, medical knowledge, interpersonal communication, practice based learning and professionalism. Each milestone was defined for three categories, early learner, advanced learner, and practitioner. CONCLUSION: A multidisciplinary task force of the NANS education committee developed a SCS training curriculum that defines ACGME milestones for basic learners, advanced learners, and practitioners.

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.

Longevity and cost of implantable intrathecal drug delivery systems for chronic pain management: a retrospective analysis of 365 patients.

OBJECTIVES: Intrathecal drug delivery systems represent an important component of interventional strategies for refractory chronic pain syndromes. Continuous intrathecal administration of opioids results in higher subarachnoid drug concentrations, improved pain scores, and less frequent side effects when compared with systemic opioid administration. Substantial costs arise at the time of surgical implantation and at revision for battery depletion or treatment of a complication. Despite current widespread use, the real-world longevity and cost of implanted intrathecal pumps (ITP) has not been fully quantified. MATERIALS AND METHODS: Patients with an ITP implanted at Cleveland Clinic Pain Management Center between January 1998 and December 2012 were included. ITP longevity was calculated as the time between implant and explant for depletion of the system's battery. Using the 2013 fee schedule of the Centers for Medicare & Medicaid Services, the daily cost of having a functioning ITP was calculated. The costs of office visits for pump refills and the cost of intrathecal medications were not included, nor were the possible savings due to decreased utilization of alternate medical services. RESULTS: Three hundred sixty-five patients had 559 pumps implanted. Postlaminectomy syndrome was the most common indication (40%). The median system longevity for all pumps was 5.4 years (97.5% confidence interval: [5.0, 5.8]), including pumps extracted prematurely, as well as those that reached the elective replacement interval. The median ITP longevity was 5.9 years (95% confidence interval: [5.6, 6.1]) for pumps explanted for end of battery life. The median system cost per day was $10.46. The median cost per day of pumps explanted for end of battery life was $9.26, versus $44.59 for pumps explanted prematurely due to complications. CONCLUSIONS: Overall, the cohort experienced an increased incidence of pump-related complications and a device longevity that was within the range of the manufacturer's anticipated lifespan. Increasing the lifespan of the ITP and improving patient selection have the potential to significantly improve the cost-effectiveness of intrathecal therapy.

Continuous transversus abdominis plane block catheter analgesia for postoperative pain control in renal transplant.

PURPOSE: Continuous transversus abdominis plane (TAP) block using a catheter has proven its usefulness in reducing opioid requirements and pain scores after lower abdominal surgery. However, there are no reports of its successful use after renal transplant. We tested the hypothesis that continuous TAP block would retrospectively reduce opioid requirement, nausea score and hospital stay after renal transplant surgery. METHODS: In a retrospective study, we reviewed the data from 63 adult renal transplant recipients-31 with patient-controlled TAP analgesia with standing orders for intravenous as well as oral opioids as needed and 32 with intravenous patient-controlled analgesia. The TAP catheter was inserted preoperatively using an ultrasound-guided technique. Infusion of ropivacaine 0.2 % at 8 ml basal, 12 ml bolus and a lockout interval of 60 min were maintained for 48 h postoperatively. The primary outcome was total morphine-equivalent dose during the 48-h postoperative period. Secondary outcomes were pain and nausea scores for the 48-h postoperative period. RESULTS: The mean 48-h postoperative morphine-equivalent doses [95 % confidence interval] for patient-controlled intravenous analgesia and TAP catheter were 197 [111, 349] and 50 [28, 90], respectively, which were significantly different (P = 0.002). The mean 48-h average verbal response pain scores were 2.94 [2.39, 3.50] and 2.49 [1.93, 3.06], respectively, which were not significantly different (P = 0.26). The mean nausea scores were 0.66 [0.46, 0.87] and 0.60 [0.40, 0.81], respectively, which were not significantly different (P = 0.69). There was no difference regarding hospital stay. CONCLUSION: The use of continuous TAP analgesia for postoperative analgesia after renal transplant was effective in reducing the morphine-equivalent requirements.

Factors that might impact intrathecal drug delivery (IDD) dose escalation: a longitudinal study.

BACKGROUND: Intrathecal drug delivery (IDD) system with implantable pumps has been used to treat cancer-related pain as well as noncancer-related chronic pain. Opioids, including morphine and hydromorphone, are the most commonly used intrathecal (IT) agents. Although technology, techniques, and knowledge of IDD have improved, dose escalation occurs relatively rapidly in noncancer pain. METHODS: Retrospective chart review of IDD pump patients, implanted for a minimum of 2 years, was designed to investigate possible existing predictors that might impact IDD dose escalation, such as patient's demographic risk factors, duration of the treatment, and diagnosis of the patient's pain correlates with increase in medication requirement. Primary outcome was defined as the annual percent escalation in daily opioid dosage, and secondary outcome was the average annual percent reduction in VRS pain scores. RESULTS: Median dosage escalation was 17% per year for patients with neuropathic pain compared with 12% per year for patients with other pain modalities. Mean opioid dosage increased 30.4% more rapidly for patients with neuropathic pain than for other pain modalities. The adjusted difference in means was 28.8% (P = 0.001). None of the secondary exposures were statistically significant after the Bonferroni adjustment. No association was found between pain modality and annual percent change in VRS pain score. CONCLUSION: Annual increases in daily opioid dosage were higher among patients with neuropathic pain than among patients with other modalities; we also found no evidence of difference in annual pain reduction.

Primary 3-Month Outcomes of a Double-Blind Randomized Prospective Study (The QUEST Study) Assessing Effectiveness and Safety of Novel High-Frequency Electric Nerve Block System for Treatment of Post-Amputation Pain.

Purpose: This multicenter, randomized, double-blinded, active sham-controlled pivotal study was designed to assess the efficacy and safety of high-frequency nerve block treatment for chronic post-amputation and phantom limb pain. Patients and Methods: QUEST enrolled 180 unilateral lower-limb amputees with severe post-amputation pain, 170 of whom were implanted with the Altius device, were randomized 1:1 to active-sham or treatment groups and reached the primary endpoint. Responders were those subjects who received ≥50% pain relief 30 min after treatment in ≥50% of their self-initiated treatment sessions within the 3-month randomized period. Differences between the active treatment and sham control groups as well as numerous secondary outcomes were determined. Results: At 30-min, (primary outcome), 24.7% of the treatment group were responders compared to 7.1% of the control group (p=0.002). At 120-minutes following treatment, responder rates were 46.8% in the Treatment group and 22.2% in the Control group (p=0.001). Improvement in Brief Pain Inventory interference score of 2.3 ± 0.29 was significantly greater in treatment group than the 1.3 ± 0.26-point change in the Control group (p = 0.01). Opioid usage, although not significantly different, trended towards a greater reduction in the treatment group than in the control group. The incidence of adverse events did not differ significantly between the treatment and control groups. Conclusion: The primary outcomes of the study were met, and the majority of Treatment patients experienced a substantial improvement in PAP (regardless of meeting the study definition of a responder). The significant in PAP was associated with significantly improved QOL metrics, and a trend towards reduced opioid utilization compared to Control. These data indicate that Altius treatment represents a significant therapeutic advancement for lower-limb amputees suffering from chronic PAP.

Ultrasound-guided transversus abdominis plane catheter for chronic abdominal pain.

BACKGROUND AND OBJECTIVES: Neural blockade of the thoracolumbar nerves supplying the anterior abdominal wall through transversus abdominis plane (TAP) has been investigated for different applications mainly for the acute pain management following abdominal surgical procedures. The role of this block for chronic pain syndromes is still to be discovered, and its value in chronic abdominal pain needs to be studied. We are presenting new application of the TAP technique for management of chronic abdominal pain syndrome using the continuous infusion. CASE REPORT: We present a case of an 18-year-old girl who underwent an uneventful laparoscopic cholecystectomy. Postoperatively, patient complained of chronic pain at the site of the surgery. All diagnostic and imaging studies were negative for a surgical or a medical cause. Multiple interventions including epidural blocks, transcutaneous electrical neural stimulation, and celiac plexus blocks had failed to relieve the pain. After discussion with the patient about the diagnostic nature of the procedure and the likelihood of recurrence of pain, TAP block was performed on the right side with significant improvement of pain for about 24 hours. The degree of pain relief experienced by the patient was very dramatic, which encouraged us to proceed with an indwelling TAP catheter to allow for continuous infusion of a local anesthetic. The patient was sent home with the continuous infusion through a TAP catheter for 2 weeks. From the day of catheter insertion and up to 9 months of follow-up, patient had marked improvement of her pain level as well as her functional status and ability to perform her daily activities, after which our acute pain team stopped following the patient. CONCLUSION: A successful TAP block confirmed the peripheral (somatic) source of the abdominal pain and provided temporary analgesia after which an indwelling catheter was inserted, which provided prolonged pain relief.

Pain Education and Knowledge (PEAK) Consensus Guidelines for Neuromodulation: A Proposal for Standardization in Fellowship and Training Programs.

The need to be competent in neuromodulation is and should be a prerequisite prior to completing a fellowship in interventional pain medicine. Unfortunately, many programs lack acceptable candidates for these advanced therapies, and fellows may not receive adequate exposure to neuromodulation procedures. The American Society of Pain and Neuroscience (ASPN) desires to create a consensus of experts to set a minimum standard of competence for neurostimulation procedures, including spinal cord stimulation (SCS), dorsal root ganglion stimulation (DRG-S), and peripheral nerve stimulation (PNS). The executive board of ASPN accepted nominations for colleagues with excellence in the subject matter of neuromodulation and physician education. This diverse group used peer-reviewed literature and, based on grading of evidence and expert opinion, developed critical consensus guides for training that all accredited fellowship programs should adopt. For each consensus point, transparency and recusal were used to eliminate bias, and an author was nominated for evidence grading oversight and bias control. Pain Education and Knowledge (PEAK) Consensus Guidelines for Neuromodulation sets a standard for neuromodulation training in pain fellowship training programs. The consensus panel has determined several recommendations to improve care in the United States for patients undergoing neuromodulation. As neuromodulation training in the United States has evolved dramatically, these therapies have become ubiquitous in pain medicine. Unfortunately, fellowship programs and the Accreditation Council for Graduate Medical Education (ACGME) pain program requirements have not progressed training to match the demands of modern advancements. PEAK sets a new standard for fellowship training and presents thirteen practice areas vital for physician competence in neuromodulation.

Long-term efficacy of high-frequency (10 kHz) spinal cord stimulation for the treatment of painful diabetic neuropathy: 24-Month results of a randomized controlled trial.

AIMS: To evaluate the long-term efficacy of high-frequency (10 kHz) spinal cord stimulation (SCS) for treating refractory painful diabetic neuropathy (PDN). METHODS: The SENZA-PDN study was a prospective, multicenter, randomized controlled trial that compared conventional medical management (CMM) alone with 10 kHz SCS plus CMM (10 kHz SCS+CMM) in 216 patients with refractory PDN. After 6 months, participants with insufficient pain relief could cross over to the other treatment. In total, 142 patients with a 10 kHz SCS system were followed for 24 months, including 84 initial 10 kHz SCS+CMM recipients and 58 crossovers from CMM alone. Assessments included pain intensity, health-related quality of life (HRQoL), sleep, and neurological function. Investigators assessed neurological function via sensory, reflex, and motor tests. They identified a clinically meaningful improvement relative to the baseline assessment if there was a significant persistent improvement in neurological function that impacted the participant's well-being and was attributable to a neurological finding. RESULTS: At 24 months, 10 kHz SCS reduced pain by a mean of 79.9% compared to baseline, with 90.1% of participants experiencing ≥50% pain relief. Participants had significantly improved HRQoL and sleep, and 65.7% demonstrated clinically meaningful neurological improvement. Five (3.2%) SCS systems were explanted due to infection. CONCLUSIONS: Over 24 months, 10 kHz SCS provided durable pain relief and significant improvements in HRQoL and sleep. Furthermore, the majority of participants demonstrated neurological improvement. These long-term data support 10 kHz SCS as a safe and highly effective therapy for PDN. TRIAL REGISTRATION: ClincalTrials.gov Identifier, NCT03228420.

Novel Technologies in Interventional Pain Management.

This article comprehensively covers 3 major novel technologies and techniques in the management of chronic lower back pain. The first 2 procedures, percutaneous interspinous spacer implantation, and minimally invasive lumbar decompression have shown significant impact in the management of lumbar spinal stenosis (LSS), especially in patients who are not great surgical candidates or are otherwise not amenable to open spinal surgery. The wealth of data for these procedures continues to increase, with up to 4 to 6-year follow-up data recently being made available. A novel solution for vertebrogenic back pain is also discussed as follow-up data emphasizes the safety and sustainability of the procedure. This article also establishes a framework for evaluating novel technologies in interventional pain management.

Telemedicine Implementation in Pain Medicine: A Survey Evaluation of Pain Medicine Practices in Spring 2020.

BACKGROUND: The COVID-19 pandemic resulted in a novel challenge for healthcare delivery and implementation in the United States (US) in 2020 and beyond. Telemedicine arose as a significant and effective medium for safe and efficacious physician-patient interactions. Prior to the COVID-19 pandemic, telemedicine while available, had infrequently been utilized in pain medicine practices due to difficulties with reimbursement, the learning curve associated with new technology usage, and the need for new logistical systems in place to implement telemedicine effectively. Given the unique constraints on the healthcare system during the COVID-19 pandemic, the ubiquitous utilization of telemedicine among pain medicine physicians increased, giving insight into potential future roles for the technology beyond the pandemic. OBJECTIVES: To survey and understand the state of implementation of telemedicine into pain medicine practices across practice settings and geographical areas; to identify potential barriers to the implementation of telemedicine in pain medicine practice; and to identify the likelihood of telemedicine continuing beyond the pandemic in pain medicine practice. STUDY DESIGN: Online questionnaire targeting Pain Medicine physicians in the US. Participants were asked questions related to the use of telemedicine during the first peak of the COVID-19 pandemic. SETTING: Online-based questionnaire distributed to academic and private practice pain medicine physicians nationally in the United States. METHODS: A 34 web-based questionnaires were distributed by the American Society of Regional Anesthesia and Pain Medicine and the Spine Intervention Society to all active members. Data were analyzed using SAS v9.4. RESULTS: Between December 3, 2020, and February 18, 2021, 164 participants accessed the survey with a response rate of 14.3%. Overall, academic physicians were more likely to implement telemedicine than private practice physicians. Telemedicine was also more frequently utilized for follow-up appointments rather than initial visits. LIMITATIONS: Although our n = 164, the overall low response rate of 14.3% warrants further investigation into the utilization of telemedicine throughout the COVID-19 pandemic. CONCLUSIONS: Telemedicine as an emerging technology for efficient communication played a key role in mitigating the adverse effects of the COVID -19 pandemic on chronic pain patients. The utilization of telemedicine remarkably increased after the start of the pandemic within 1 to 2 weeks. Overall, private hospital-based centers were significantly less likely to implement telemedicine than academic centers, possibly due to limited access to secure telemedicine platforms and high start-up costs. Telemedicine was used more frequently for follow-up visits than initial visit encounters at most centers. In spite of the unforeseen consequences to the healthcare system and chronic pain practices in the US from COVID-19, telehealth has emerged as a unique model of care for patients with chronic pain. Although it has flaws, telehealth has the ability to increase access to care beyond the end of the pandemic. Further identification of barriers to the use of telemedicine platforms in private practices should be addressed from a policy perspective to facilitate increased care access.

High-Frequency 10-kHz Spinal Cord Stimulation Improves Health-Related Quality of Life in Patients With Refractory Painful Diabetic Neuropathy: 12-Month Results From a Randomized Controlled Trial.

Objective: To evaluate high-frequency (10-kHz) spinal cord stimulation (SCS) treatment in refractory painful diabetic neuropathy. Patients and Methods: A prospective, multicenter randomized controlled trial was conducted between Aug 28, 2017 and March 16, 2021, comparing conventional medical management (CMM) with 10-kHz SCS+CMM. The participants had hemoglobin A1c level of less than or equal to 10% and pain greater than or equal to 5 of 10 cm on visual analog scale, with painful diabetic neuropathy symptoms 12 months or more refractory to gabapentinoids and at least 1 other analgesic class. Assessments included measures of pain, neurologic function, and health-related quality of life (HRQoL) over 12 months with optional crossover at 6 months. Results: The participants were randomized 1:1 to CMM (n=103) or 10-kHz SCS+CMM (n=113). At 6 months, 77 of 95 (81%) CMM group participants opted for crossover, whereas none of the 10-kHz SCS group participants did so. At 12 months, the mean pain relief from baseline among participants implanted with 10-kHz SCS was 74.3% (95% CI, 70.1-78.5), and 121 of 142 (85%) participants were treatment responders (≥50% pain relief). Treatment with 10-kHz SCS improved HRQoL, including a mean improvement in the EuroQol 5-dimensional questionnaire index score of 0.136 (95% CI, 0.104-0.169). The participants also reported significantly less pain interference with sleep, mood, and daily activities. At 12 months, 131 of 142 (92%) participants were "satisfied" or "very satisfied" with the 10-kHz SCS treatment. Conclusion: The 10-kHz SCS treatment resulted in substantial pain relief and improvement in overall HRQoL 2.5- to 4.5-fold higher than the minimal clinically important difference. The outcomes were durable over 12 months and support 10-kHz SCS treatment in patients with refractory painful diabetic neuropathy. Trial registration: clincaltrials.gov Identifier: NCT03228420.

Retrospective review of 707 cases of spinal cord stimulation: indications and complications.

Appropriate patient selection and minimizing complications are critical for successful spinal cord stimulation (SCS) therapy in managing intractable pain. We thus reviewed electronic medical records of 707 consecutive cases of patients who received SCS therapy in the Cleveland Clinic from 2000 to 2005 with an emphasis on indications and complications. SCS was used to treat complex regional pain syndrome (CRPS) (345 cases), failed back surgery syndrome (235 cases), peripheral vascular disease (20 cases), visceral pain in the chest, abdomen, and pelvis (37 cases), and peripheral neuropathy (70 cases). CRPS and failed back surgery syndrome accounted for 82% of the cases. The implant-to-trial ratio was 75% on average, with the highest for CRPS type 2 (83%) and the lowest for peripheral vascular diseases (65%). The only documented complication associated with SCS trials was lead migration in 5 of 707 patients (0.7%). There were no permanent neurological deficits or deaths as a result of SCS implant or its complications. Hardware-related complications were common (38%) and included lead migration (22.6%), lead connection failure (9.5%), and lead breakage (6%). Revisions or replacements were required in these cases. Biologically related complications included pain at the generator site (12%) and clinical infection (4.5%; 2.5% with positive culture). The rates of infection varied among the different diagnoses with the highest in failed back surgery syndrome (6.3%). Patients with diabetes had an infection rate of 9%, over the 4% in non-diabetics. Infections were managed successfully with explantation and antibiotic therapy without permanent sequela.

Establishing a Dose-Response Relationship Between Opioid Use and Hypogonadism: A Retrospective Case-Control Study.

Background: Opioid-induced androgen deficiency (OPIAD) related to chronic, long-acting opioid use can be a significant detriment to patient quality of life. The aim of this study was to investigate the association between chronic opioid use and hypogonadism. Methods: A single-center, retrospective, matched case-control analysis of 357 males (94 cases, 263 controls, aiming for 1:4 matching) was performed. Study subjects were ages 18 to 80 years and had a diagnosis of chronic opioid use. Patients with a hypogonadism diagnosis were matched to patients without a hypogonadism diagnosis by age, ethnicity, and body mass index. The maximum morphine equivalent daily dose (MEDD) was compared in each group. Results: A significant linear association between MEDD and the odds of developing hypogonadism (P<0.001) in males with chronic use of opioids was observed, with an odds ratio of 1.44 (95% CI 1.16-1.78) by 100-unit difference in maximum MEDD. Conclusion: Results showed a significant, positive linear association between chronic opioid dose and the odds of developing hypogonadism in males. This higher index of suspicion of OPIAD could lead to earlier recognition of symptoms and increase the positive predictive value of diagnostic laboratory tests.

Effect of High-frequency (10-kHz) Spinal Cord Stimulation in Patients With Painful Diabetic Neuropathy: A Randomized Clinical Trial.

Importance: Many patients with diabetic peripheral neuropathy experience chronic pain and inadequate relief despite best available medical treatments. Objective: To determine whether 10-kHz spinal cord stimulation (SCS) improves outcomes for patients with refractory painful diabetic neuropathy (PDN). Design, Setting, and Participants: The prospective, multicenter, open-label SENZA-PDN randomized clinical trial compared conventional medical management (CMM) with 10-kHz SCS plus CMM. Participants with PDN for 1 year or more refractory to gabapentinoids and at least 1 other analgesic class, lower limb pain intensity of 5 cm or more on a 10-cm visual analogue scale (VAS), body mass index (calculated as weight in kilograms divided by height in meters squared) of 45 or less, hemoglobin A1c (HbA1c) of 10% or less, daily morphine equivalents of 120 mg or less, and medically appropriate for the procedure were recruited from clinic patient populations and digital advertising. Participants were enrolled from multiple sites across the US, including academic centers and community pain clinics, between August 2017 and August 2019 with 6-month follow-up and optional crossover at 6 months. Screening 430 patients resulted in 214 who were excluded or declined participation and 216 who were randomized. At 6-month follow-up, 187 patients were evaluated. Interventions: Implanted medical device delivering 10-kHz SCS. Main Outcomes and Measures: The prespecified primary end point was percentage of participants with 50% pain relief or more on VAS without worsening of baseline neurological deficits at 3 months. Secondary end points were tested hierarchically, as prespecified in the analysis plan. Measures included pain VAS, neurological examination, health-related quality of life (EuroQol Five-Dimension questionnaire), and HbA1c over 6 months. Results: Of 216 randomized patients, 136 (63.0%) were male, and the mean (SD) age was 60.8 (10.7) years. Additionally, the median (interquartile range) duration of diabetes and peripheral neuropathy were 10.9 (6.3-16.4) years and 5.6 (3.0-10.1) years, respectively. The primary end point assessed in the intention-to-treat population was met by 5 of 94 patients in the CMM group (5%) and 75 of 95 patients in the 10-kHz SCS plus CMM group (79%; difference, 73.6%; 95% CI, 64.2-83.0; P < .001). Infections requiring device explant occurred in 2 patients in the 10-kHz SCS plus CMM group (2%). For the CMM group, the mean pain VAS score was 7.0 cm (95% CI, 6.7-7.3) at baseline and 6.9 cm (95% CI, 6.5-7.3) at 6 months. For the 10-kHz SCS plus CMM group, the mean pain VAS score was 7.6 cm (95% CI, 7.3-7.9) at baseline and 1.7 cm (95% CI, 1.3-2.1) at 6 months. Investigators observed neurological examination improvements for 3 of 92 patients in the CMM group (3%) and 52 of 84 in the 10-kHz SCS plus CMM group (62%) at 6 months (difference, 58.6%; 95% CI, 47.6-69.6; P < .001). Conclusions and Relevance: Substantial pain relief and improved health-related quality of life sustained over 6 months demonstrates 10-kHz SCS can safely and effectively treat patients with refractory PDN. Trial Registration: ClincalTrials.gov Identifier: NCT03228420.