Early Functional Outcomes in Low Back Pain Subjects with a Novel Interspinous Fusion Device: REFINE Study 6-Month Results.

Purpose: Lumbar interlaminar decompression with interspinous fixation is an established safe and effective treatment for spinal stenosis. Early maintenance of improvements in pain intensity and function are critical for durability of symptom relief. The purpose of this study was to investigate the efficacy of minimally invasive treatments for low back pain during the early period after treatment and their utility in setting the course for longer term success. Patients and Methods: This study utilized patient evaluations at 3- and 6-months following treatment and is part of an actively enrolling, institutional review board (IRB) approved, single-arm, multicenter, prospective, open-label 12-month study. Clinical efficacy was assessed primarily using the change from baseline in Oswestry Disability Index (ODI), Visual Analog Scale (VAS) of the back and leg pain during walking and standing, and Zurich Claudication Questionnaire (ZCQ), and secondarily using the Patient Global Impression of Change (PGIC) and Patient-Reported Outcomes Measurement Information System (PROMIS) 29 v2.1. The safety endpoints were the adverse events and reoperations or revisions at the index level(s). Results: At 6-month post-op, 76%, 62%-64%, and 64% of patients demonstrated clinical meaningful, and statistically significant improvement in their pain as defined by ZCQ, VAS (back and leg), and ODI, respectively. In addition, 78% of patients noted improvement in PGIC. Two procedure-related adverse events were noted which fully resolved without surgical intervention. Conclusion: This 6-month interim analysis at 42% enrollment of patients was conducted to determine prolonged safety and efficacy of the interspinous fusion device. Our analysis showed a sustained improvement in clinical efficacy, and safety endpoints, when compared to the 3-months evaluations, across both interventional pain and neurosurgery specialties.

A Prospective, Observational, Open-Label, Non-Randomized, Multicenter Study Measuring Functional Outcomes in a Novel Interspinous Fusion Device in Subjects with Low Back Pain: REFINE Study.

INTRODUCTION: Lumbar degenerative disease and the accompanying pain and dysfunction affect a significant number of patients in the USA and around the world. As surgery and innovation are moving towards minimally invasive treatments, this study looks to explore interspinous fixation as a standalone posterior approach to treat lumbar degenerative disc disease in the presence of neurogenic claudication and spinal stenosis. METHODS: This study was approved by an institutional review board (IRB) and is actively enrolling in a single-arm, multicenter, prospective, open-label fashion. Patients are followed with reporting at 3 months, and 12 months for primary endpoint analysis of efficacy and safety based on improved composite endpoints relative to baseline, with success defined as greater than 20 mm back pain reduction in Visual Analog Scale 100 mm (VAS) while standing or walking, greater than 20 mm leg pain reduction in VAS while standing or walking, Zurich Claudication Questionnaire (ZCQ) improvement of 0.5 or greater in two or three domains, Oswestry Disability Index (ODI) improvement of a least 10 points and no reoperations or revisions at the index level(s). Secondary endpoints included a multidimensional assessment in the Patient-Reported Outcomes Measurement Information System (PROMIS) 29 v2.1 and Patient Global Impression of Change (PGIC). RESULTS: In this interim 3-month analysis, 82% of patients reported they were improved from the procedure, while 65% of patients demonstrated clinical meaningful improvement in their pain and function, as defined by the VAS, ODI, and ZCQ. There was only one adverse event and no complications were identified at last clinic research follow-up visit. CONCLUSIONS: This interim analysis of the first 20% of the enrolled patients out to 3 months was to determine safety of the procedure and report on adverse events, acknowledging the heterogeneity of surgical specialty. Further follow-up and greater numbers are needed as the study is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT05504499.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations on Best Practices for Cervical Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise with international representation to establish evidence-based guidance on the use of neurostimulation in the cervical region to improve outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for an often-overlooked area of neurostimulation practice. MATERIALS AND METHODS: Authors were chosen based upon their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to the present. Identified studies were graded using the US Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the use of cervical neuromodulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be utilized as a guide to assist decision making when clinically appropriate.

Interspinous Process Decompression With The Superion® Spacer For Lumbar Spinal Stenosis: Real-World Experience From A Device Registry.

BACKGROUND: Interspinous process decompression (IPD) with stand-alone spacers has demonstrated excellent long-term clinical benefit for patients with lumbar spinal stenosis (LSS). METHODS: IPD used the Superion® Indirect Decompression System (Vertiflex, Carlsbad, CA, USA). Perioperative and clinical data were captured via a registry for patients treated with IPD for LSS with intermittent neurogenic claudication. Three-hundred sixteen physicians at 86 clinical sites in the US participated. Patient data were captured from in-person interviews and a phone survey. Outcomes included intraoperative blood loss, procedural time, leg and back pain severity (100 mm VAS), patient satisfaction and treatment approval at 3 weeks, 6 and 12 months. RESULTS: The mean age of registry patients was 73.0 ± 9.1 years of which 54% were female. Mean leg pain severity decreased from 76.6 ± 22.4 mm preoperatively to 30.4 ± 34.6 mm at 12 months, reflecting an overall 60% improvement. Corresponding responder rates were 64% (484 of 751), 72% (1,097 of 1,523) and 75% (317 of 423) at 3 weeks, 6 and 12 months, respectively. Back pain severity improved from 76.8 ± 22.2 mm preoperatively to 39.9 ± 32.3 mm at 12 months (48% improvement); 12-month responder rate of 67% (297 of 441). For patient satisfaction at 3 weeks, 6 and 12 months, 89%, 80%, and 80% were satisfied or somewhat satisfied with their treatment and 90%, 75%, and 75% would definitely or probably undergo the same treatment again. In the phone survey, the rate of revision was 3.6% (51 of 1,426). CONCLUSION: These registry findings support the clinical adoption of minimally invasive IPD in patients with neurogenic claudication associated with LSS.

Spinal Cord Stimulation (SCS) with Anatomically Guided (3D) Neural Targeting Shows Superior Chronic Axial Low Back Pain Relief Compared to Traditional SCS-LUMINA Study.

BACKGROUND: The aim of this study was to determine whether spinal cord stimulation (SCS) using 3D neural targeting provided sustained overall and low back pain relief in a broad routine clinical practice population. STUDY DESIGN AND METHODS: This was a multicenter, open-label observational study with an observational arm and retrospective analysis of a matched cohort. After IPG implantation, programming was done using a patient-specific, model-based algorithm to adjust for lead position (3D neural targeting) or previous generation software (traditional). Demographics, medical histories, SCS parameters, pain locations, pain intensities, disabilities, and safety data were collected for all patients. RESULTS: A total of 213 patients using 3D neural targeting were included, with a trial-to-implant ratio of 86%. Patients used seven different lead configurations, with 62% receiving 24 to 32 contacts, and a broad range of stimulation parameters utilizing a mean of 14.3 (±6.1) contacts. At 24 months postimplant, pain intensity decreased significantly from baseline (ΔNRS = 4.2, N = 169, P < 0.0001) and even more in in the severe pain subgroup (ΔNRS = 5.3, N = 91, P < 0.0001). Axial low back pain also decreased significantly from baseline to 24 months (ΔNRS = 4.1, N = 70, P < 0.0001, on the overall cohort and ΔNRS = 5.6, N = 38, on the severe subgroup). Matched cohort comparison with 213 patients treated with traditional SCS at the same centers showed overall pain responder rates of 51% (traditional SCS) and 74% (neural targeting SCS) and axial low back pain responder rates of 41% and 71% in the traditional SCS and neural targeting SCS cohorts, respectively. Lastly, complications occurred in a total of 33 of the 213 patients, with a 1.6% lead replacement rate and a 1.6% explant rate. CONCLUSIONS: Our results suggest that 3D neural targeting SCS and its associated hardware flexibility provide effective treatment for both chronic leg and chronic axial low back pain that is significantly superior to traditional SCS.

The Neurostimulation Appropriateness Consensus Committee (NACC) Recommendations for Infection Prevention and Management.

INTRODUCTION: The use of neurostimulation for pain has been an established therapy for many decades and is a major tool in the arsenal to treat neuropathic pain syndromes. Level I evidence has recently been presented to substantiate the therapy, but this is balanced against the risk of complications of an interventional technique. METHODS: The Neurostimulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society convened an international panel of well published and diverse physicians to examine the best practices for infection mitigation and management in patients undergoing neurostimulation. The NACC recommendations are based on evidence scoring and peer-reviewed literature. Where evidence is lacking the panel added expert opinion to establish recommendations. RESULTS: The NACC has made recommendations to improve care by reducing infection and managing this complication when it occurs. These evidence-based recommendations should be considered best practices in the clinical implantation of neurostimulation devices. CONCLUSION: Adhering to established standards can improve patient care and reduce the morbidity and mortality of infectious complications in patients receiving neurostimulation.

Use of a newly developed delivery device for percutaneous introduction of multiple lead configurations for spinal cord stimulation.

OBJECTIVE: The Epiducer lead delivery system is a novel lead delivery device that can be used to percutaneously implant S-Series paddle leads (St. Jude Medical, Plano, TX, USA) as well as multiple percutaneous leads obviating the need for laminectomy and/or multiple needle sticks, respectively. This study evaluates the safety and usage of the Epiducer lead delivery system. METHODS: An Institutional Review Board-approved observational data collection study was conducted to evaluate usage patterns of the Epiducer system. In addition to the number and frequency of different lead configurations, the following procedural aspects of the surgery were recorded during the evaluation: angle of entry, distance from entry to final lead placement, and physician feedback. Descriptive statistics on adverse events, procedural aspects, and patient outcomes were compiled. RESULTS: Data were collected from 163 patients across 25 investigational sites. Physicians successfully implanted patients using the Epiducer during 89% of the procedures. Seven possible lead configurations were implanted. There were 96% and 92% of physicians "satisfied" or "very satisfied" with accessing the epidural space and placing multiple leads with the Epiducer delivery system, respectfully. Eighty-nine percent of physicians were "satisfied" or "very satisfied" with implanting an S-Series paddle lead using the Epiducer delivery system. Ninety-five percent of physicians were "satisfied" or "very satisfied" with the Epiducer delivery system overall. Ten patients (6%) experienced adverse events. CONCLUSION: Results suggest that the Epiducer delivery system allows for the safe and successful percutaneous implantation of paddle leads and/or multiple lead configurations. Furthermore, physicians are satisfied with the Epiducer delivery system.

The prospective evaluation of safety and success of a new method of introducing percutaneous paddle leads and complex arrays with an epidural access system.

OBJECTIVES: Spinal cord stimulation (SCS) has become a mainstay in the continuum of care for patients suffering from chronic neuropathic pain of the trunk and limbs. Options for placing these devices have included a percutaneous method of using an epidural needle to place a cylindrical (percutaneous) lead to stimulate the spinal cord, or an open laminotomy method for placing a paddle lead at the location of the surgical decompression of the laminae. Both of these methods have been successful in a high percentage of patients, but neither have been ideal. Limitations of the percutaneous leads have been inefficiency of power delivery, inability to achieve desired depth of stimulation in the spinal cord, occasional lead migration and difficulty covering complex pain patterns. Limitations of the paddle lead have been the need for surgical laminotomy, inability to steer the lead once placed, limits on placement in the vicinity of the surgical decompression, and a perceived risk of increased bleeding and trauma to the tissue. These factors have led many minimally invasive spine specialists to seek new options for SCS. This paper presents the initial US experience with a newly approved device to place both paddle leads, and multi-lead arrays into the epidural space via a percutaneous Seldinger-guided approach through a single needle placement. We will both describe the technique and review the outcomes of some of the early cases. MATERIALS AND METHODS: After Investigational Review Board clearance, patients consented to data collection in a prospective fashion regarding the use of a new percutaneous epidural introducer (Epiducer, St. Jude Neurological, Minneapolis, MN, USA) to place paddle leads and complex lead arrays. The patients underwent education regarding expectations and risks of the procedure consistent with our normal preoperative period. Patients underwent preoperative anesthesia screening and proper testing as outlined by the Joint Commission on Hospital Accreditation, and were given the opportunity to ask questions concerning the procedure. Once the patient wished to move forward, they were consented using the approved case reporting form and followed during the course of their care. The initial cases were performed in West Virginia with subsequent cases following at the other centers involved in this analysis. The outcomes of this analysis focused on three areas: 1. The technical success in placing the percutaneous sheath. This included the ability to successfully complete: • epidural access with a 14-gauge Tuohy needle • ability to place a styleted guidewire • ability to introduce the introduction system over the wire into the epidural space • ability to remove the guidewire and introduction tip leaving the 10-gauge sheath intact. 2. The ability to place the desired lead or leads into the epidural space via the percutaneous introduction sheath. 3. The presence of any major adverse event which were defined as: • nerve injury • paraplegia • worsening of baseline pain • epidural hematoma • epidural infection • dural tear • dural rent • retained device that could not be removed. This information was carefully recorded for each implant, and summarized in this communication. RESULTS: During the initial 30 days of the evaluation period, 43 epidural introduction systems were attempted in 38 patients. In patients in whom more than one paddle lead was placed, the system required the reinsertion of the guidewire through the Epiducer, removal of the Epiducer, and rewiring over the guidewire. This is necessary because the diameter of a paddle lead does not allow two or three leads to be placed without rewiring the system. The success of placement was 42/43, with inability to access the epidural space in one patient in whom ligamentum flavum hypertrophy was present on the preoperative imaging study. In all patients, the system was placed at the L1-L2 level, or lower, based on the Food and Drug Administration labeling. The total numbers of leads placed were 75, with both paddle and percutaneous arrays implanted successfully. There were no adverse events during this prospective surveillance evaluation. Ten patients complained of soreness at the entry site and post-procedure stiffness. These complaints were treated with ice, rest, and analgesics and resolved without incident. CONCLUSION: This paper describes the initial US cases of the placement of a paddle lead via a minimally invasive percutaneous method, as well as complex cylindrical arrays with a single needle entry to the epidural space. The device functioned successfully and presented a safe option for placing paddle leads and complex arrays.

Spinal cord stimulation in the treatment of acute and chronic vasculitis: clinical discussion and synopsis of the literature.

OBJECTIVES: Spinal cord stimulation (SCS) has been widely noted as a treatment for ischemic pain secondary to peripheral vascular disease, but evidence in the vasculitis disease state is lacking. In this paper we present two cases that exemplify the potential of SCS in this unique population. MATERIAL AND METHODS: Two case studies involving patients with the conditions noted including initial findings, treatment protocol, and results documented throughout the treatment regimen. A comprehensive review of the critical literature also was performed. RESULTS: Both patients showed marked improvement with SCS. Pain scores improved dramatically, with a major improvement in disease symptom and quality of life. CONCLUSIONS: Based on literature and our results, SCS is an effective and safe therapy for patients with therapeutically refractory vasculitis.

Inflammatory mass of an intrathecal catheter in patients receiving baclofen as a sole agent: a report of two cases and a review of the identification and treatment of the complication.

INTRODUCTION: Intrathecal inflammatory masses or granuloma have been described extensively in the literature in patients receiving chronic spinal infusions for pain. After an extensive literature review, no reported cases of baclofen causing this disorder when administered as a sole agent were identified. Intrathecal baclofen has been used to treat spasticity secondary to stroke, multiple sclerosis, cerebral palsy, spinal cord injury, and other neurological disease. CASES: Two patients who received intrathecal infusions of baclofen to treat spasticity developed catheter failure. Magnetic resonance imaging analysis showed the presence of an inflammatory mass at the tip of each catheter causing the dysfunction. The catheters were removed and replaced by a percutaneous technique. DISCUSSION: Inflammatory mass on an intrathecal catheter can result in a variety of symptoms. These problems range from the patient being asymptomatic to flaccid paraplegia. Animal studies have shown an association with high concentrations of morphine and hydromorphone theorized to be related to a mast cell degranulation response. Presence of this lesion in these two patients should heighten the suspicion for inflammatory mass in any patient treated for spasticity. The diagnosis of intrathecal catheter tip inflammatory mass is made after an initial suspicion of a catheter occlusion or failure. The gold standard of diagnosis is T2-weighted magnetic resonance imaging. A computerized tomography myelogram is acceptable if a magnetic resonance imaging is not feasible. CONCLUSION: We report two cases of inflammatory mass in patients receiving baclofen as a sole intrathecal agent. The authors would recommend vigilance in any patient receiving intrathecal baclofen. If the suspicion arises of this problem, a magnetic resonance imaging or computerized tomography myelogram should be obtained with a focus on the catheter tip.

Spinal cord stimulation for refractory angina pectoris and peripheral vascular disease.

Spinal cord stimulation has been used in clinical practice for more than three decades. The primary use of this therapy has been in spine-related disorders. In recent years, the therapy has been used more extensively in diseases of the vascular system. Increasingly, interest has piqued in using this mode of treatment for refractory angina and ischemic pain secondary to peripheral vascular disease. In this publication, we review the current literature on these two indications and present case examples of both therapies.