Hagedorn, Jonathan M.

Abstract Background Spinal cord stimulation (SCS) is a highly effective therapy for treatment of chronic pain, however due to the complexity of pain, measuring a subject’s long-term response to the therapy remains difficult. Frequent measurement of patient-reported outcomes (PROs) to reflect multiple aspects of subjects’ pain is a crucial step in determining therapy outcomes. However, collecting full-length PROs is burdensome for both patients and clinicians. The objective of this work is to investigate the feasibility of using limited sets of outcomes from multiple PROs to accurately characterize subjects’ response to SCS therapy. Methods Validated PROs were used to capture pain, physical function and disability, as well as psychometric, satisfaction, and global health metrics. PROs were collected from 509 patients implanted with a neurostimulator enrolled in the post-market REALITY study. Combination of Pearson’s correlation and factor analysis was used to eliminate highly correlated questions and find the minimal meaningful set of questions within the predefined domains of each scale. Results The shortened versions of the questionnaires presented almost identical accuracy for classifying SCS therapy outcome as compared to the validated full-length versions. In addition, principal component analysis was performed on all the PROs and showed a robust clustering of pain intensity, psychological factors, physical function, and sleep across multiple PROs. A selected set of questions captured from multiple PROs can provide adequate information for measuring SCS therapy outcomes. Conclusions These shorter and more targeted PROs could result in better patient engagement, enhanced and more frequent data collection processes for digital health platforms, and ultimately increased patient satisfaction with SCS therapy. Trial registration Data for our analysis were extracted from the ongoing prospective, multicenter, international REALITY (Long-Term Real-World Outcomes Study on Patients Implanted with a Neurostimulator) study (NCT03876054).

Introduction Applicants to chronic pain medicine fellowship programs often express confusion regarding the importance of various selection criteria. This study sought to elucidate program directors’ considerations in applicant selection for fellowship interviews and ranking and to correlate these criteria with match statistics to provide a guide for prospective candidates. Methods An electronic survey was sent to all Accreditation Council for Graduate Medical Education-accredited chronic pain fellowship directors. The importance of various applicant characteristics were evaluated and compared with recent match data. Results Fifty-seven program directors completed the survey. The most important factors involved in applicant interview selection were perceived commitment to the specialty, letters of recommendation from pain faculty, scholarly activities, and leadership experiences. Although completion of a pain rotation was valued highly, experience with procedures was of relatively low importance. There was no preference if rotations were completed within the responders’ department. Variability was noted when considering internal applicants or the applicant’s geographic location. When citing main factors in ranking applicants, interpersonal skills, interview impression and applicant’s fit within the institution were highly ranked by most responders. Discussion Assessment of an applicant’s commitment to chronic pain is challenging. Most responders prioritize the applicant’s commitment to chronic pain as a specialty, scholarly activity, participation in chronic pain rotations, pain-related conferences and letters of recommendation from pain faculty. Chronic pain medicine fellowship candidates should establish a progressive pattern of genuine interest and involvement within the specialty during residency training to optimize their fellowship match potential.

Abstract Aims The aim of our study was to review the surgical literature regarding the relationship between hemoglobin A1c (HbA1c), diagnosis of diabetes mellitus (DM), and risk of postoperative surgical site infection (SSI). Methods A librarian‐assisted literature search was performed with two goals: (1) identify surgical publications related to SSI and HbA1c values, and (2) identify publications reporting infection risk with DM in spinal cord stimulation (SCS), intrathecal drug delivery systems (IDDS), and cardiovascular implantable electronic device (CIED) implantation surgeries. Published guidelines on perioperative management of DM are reviewed. Results We identified 30 studies reporting SSI and HbA1c values. The literature review indicated that for many surgical procedures, elevated HbA1c is not correlated to rate of SSI. We identified 16 studies reporting infection rates within DM cohorts following SCS, IDDS, and CIED implantation surgeries. The data reviewed did not indicate DM as an independent risk factor for SSI. Conclusion Preoperative HbA1c levels in patients with a history of DM is not a singularly sufficient tool to estimate risk of perioperative infection in SCS implantation surgery. Published guidelines on perioperative management of DM do not suggest a specific HbA1c above which surgery should be delayed; intentional perioperative glycemic control is recommended.

Abstract Introduction Lumbar spinal stenosis affects more than 200,000 adults in the United States, resulting in approximately 38,000 operations among the Medicare population and greater than $1.5 billion in hospital bills alone. Fortunately, Minimally Invasive Lumbar Decompression (MILD) and the Superion Indirect Decompression System have shown lasting benefit and cost savings compared to more aggressive surgical options. Objective Our primary objective was to retrospectively determine the rate of lumbar decompression surgery following the MILD and Superion procedures. Materials and Methods This was a pooled retrospective review of LSS patients who received MILD and/or Superion procedures between January 2011 and July 2019. Adult patients with CPT codes for MILD and Superion procedures were identified. Patients were included if they had a follow‐up visit at least 2 years from the procedure date, preprocedural MRI results, and surgical notes. Results A total of 199 patients were included in the final analysis, of which 57 patients (28.6%) underwent MILD procedure only, 124 patients (62.3%) underwent Superion only, and 18 patients (9.0%) underwent an MILD procedure initially followed by a Superion procedure. Two patients had an MILD procedure performed twice at the same level at separate encounters. A total of four patients in the entire cohort (2.0%; MILD 5.3%, Superion 0.8%) underwent subsequent lumbar spine surgery when followed for at least 2 years. It is notable that some of these patients may not have been surgical candidates and this may have skewed the results. Conclusions Patients undergoing minimally invasive decompression treatment of lumbar spinal stenosis have low rates of subsequent open surgery which potentially results in cost savings and a reduction in severe adverse events. The reason for low surgical rate may reflect improvement in their symptoms, a preference to avoid surgery, or being deemed not a surgical candidate.

Background: High-frequency (10-kHz) spinal cord stimulation (SCS) continues to be an emerging therapy in chronic pain management. The same complications that plagued earlier SCS systems may affect newer stimulation technologies, although there is limited data on the type of complications and surgical management of these complications. Objective: The aim of this study was to systematically examine real-world complications associated with 10-kHz SCS reported on the Manufacturer and User Facility Device Experience (MAUDE) database. Materials and Methods: The MAUDE database was queried for entries reported between January 1, 2016 and December 31, 2020. Entries were classified into procedural complications, device-related complications, patient complaints, surgically managed complications, serious adverse events, and/or other complications. Primary outcomes included type and frequency of complications, and surgical management of complications. Results: A total of 1651 entries were analyzed. Most entries were categorized as procedural complications (72.6%), followed by serious adverse events (10.5%), device-related complications (10.5%), and patient complaints (9.9%). Most complications were managed surgically with explant (50.9%) rather than revision (5.0%) or incision/drainage (6.6%). Of procedural complications, the most common entries included non-neuraxial infection (52.9%), new neurological symptoms (14.7%), and dural puncture (9.5%). Of device-related complications, the most common entries included lead damage (41.6%), erosion (18.5%), and difficult insertion (11.5%). Conclusion: This retrospective 5-year analysis of complications from10-kHz SCS provides a real-world assessment of safety data unique for this stimulation modality. This analysis may help inform future clinical decisions, lead to device enhancement and optimization, and improve mitigation of risks to provide safe and efficacious use of 10-kHz SCS.

Abstract Introduction Dorsal root ganglion stimulation (DRG‐S), has demonstrated superiority in the treatment of complex regional pain syndrome and causalgia. Lead migration and fracture impact DRG‐S therapeutic stability. Lead anchoring reduces DRG‐S lead migration without increasing lead fracture. Lead fracture may be related to lead entrapment in the superficial fascial plane. A novel medialized approach for lead placement and anchoring is presented to address these issues. Methods We suggest an alternative technique for implanting percutaneous DRG‐S leads at the T10‐L5 levels. Results A novel medialized ipsilateral technique for lead placement and anchoring for single, bilateral, and adjacent segment placement is presented. The Tuohy needle puncture site is medial to the pedicle and adjacent to the spinous process, two vertebral levels caudad to the target foramen. Trajectory is maintained in the sagittal plane, to access the caudad interlaminar space near the midline. This technique allows for ipsilateral or contralateral lead placement. After epidural access, the introducer sheath is rotated toward the targeted foramen and advanced. The guidewire followed by the lead is passed, and once lead position is confirmed, tension “S” loops are created, followed by anchoring to the deep fascia. Conclusion We describe a new paramedian technique for DRG‐S lead placement. We propose it will decrease DRG‐S complication rates through anchoring to reduce migration and by avoiding the fascial planes thought to be responsible for fracture. Long‐term outcomes applying our proposed techniques are required for determining the true impact, however, early anecdotal results suggest that these new techniques are favorable.

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.