UNASSIGNED: Spinal cord stimulation (SCS) is a highly effective treatment for chronic neuropathic pain. Despite recent advances in technology, treatment gaps remain. A small SCS system with a miniaturized implantable pulse generator (micro-IPG; <1.5 cm3 in volume) and an externally worn power source may be preferred by patients who do not want a large, implanted battery. We report here the long-term outcomes from the first-in-human study evaluating the safety and performance of a new neurostimulation system.
UNASSIGNED: This was a prospective, multi-center, open-label, single-arm study to evaluate this SCS system, in the treatment of chronic, intractable leg and low-back pain. Consented subjects who passed screening continued on to the long-term phase of the study. One-year, patient-reported outcomes (PRO\'s) such as pain (Numeric Rating Scale, NRS), functional disability, quality of life, and mood were captured.
UNASSIGNED: Twenty-six (26) evaluable subjects with permanent implants were included in this analysis. The average leg pain NRS score decreased from 6.8 ± 1.2 at baseline to 1.1 ± 1.2 at the end of the study (p < 0.001), while the average low-back pain NRS score decreased from 6.8 ± 1.2 to 1.5 ± 1.2 (p < 0.001). The responder rate (proportion with ≥50% pain relief) was 91% in the leg(s) and 82% in the low back. There were significant improvements in functional disability (Oswestry Disability Index) and in mood (Beck Depression Inventory), demonstrating a 46% and 62% improvement, respectively (p < 0.001). Eleven-point Likert scales demonstrated the wearable to be very comfortable and very easy to use.
UNASSIGNED: There were considerable challenges conducting a clinical study during the COVID-19 pandemic, such as missed study programming visits. Nevertheless, subjects had significant PRO improvements through 1-year. The small size of the implanted device, along with a proprietary waveform, may allow for improved SCS outcomes and a drop in incidence of IPG-pocket pain.

Refractory persistent spinal pain syndrome after surgery (PSPS-T2) can be successfully addressed by spinal cord stimulation (SCS). While conventional stimulation generates paresthesia, recent systems enable the delivery of paresthesia-free stimulation. Studies have claimed non-inferiority/superiority of selected paresthesia-free stimulation compared with paresthesia-based stimulation, but the comparative efficacy between different waveforms still needs to be determined in a given patient. We designed a randomized controlled 3-month crossover trial to compare pain relief of paresthesia-based stimulation versus high frequency versus burst in 28 PSPS-T2 patients implanted with multiwave SCS systems. Our secondary objectives were to determine the efficacy of these 3 waveforms on pain surface, quality of life, functional capacity, psychological distress, and validated composite multidimensional clinical response index to provide holistic comparisons at 3-, 6-, 9-, and 15-month post-randomization. The preferred stimulation modality was documented during the follow-up periods. No difference between the waveforms was observed in this study (P = .08). SCS led to significant pain relief, quality of life improvement, improvement of multidimensional clinical response index, and of all other clinical outcomes at all follow-up visits. Forty-four percent of the patients chose to keep the paresthesia-based stimulation modality after the 15-month follow-up period. By giving the possibility to switch and/or to combine several waveforms, the overall rate of SCS responders further increased with 25%. In this study, high frequency or burst do not appear superior to paresthesia-based stimulation, wherefore paresthesia-based stimulation should still be considered as a valid option. However, combining paresthesia-based stimulation with paresthesia-free stimulation, through personalized multiwave therapy, might significantly improve SCS responses. PERSPECTIVE: This article assesses clinical SCS efficacy on pain relief, by comparing paresthesia-based stimulation and paresthesia-free stimulation (including high frequency and burst) modalities in patient presenting with PSPS-T2. Switching and/or combining waveforms contribute to increasing the global SCS responders rate.

Percutaneous epidural adhesiolysis (PEA) is a minimal invasive procedure to relieve sciatalgia caused by post lumbar surgery syndrome (PLSS). Fluoroscopic-guided contrast-epidurography is essential to ensure a safe procedure. We present a case of a 28-year-old male patient who underwent a PEA which was complicated by a dural puncture. We highlight the dangers of such complications and discuss associated risk factors.

OBJECTIVE: Conventional spinal cord stimulators (SCSs) have demonstrated efficacy in individuals with failed back surgery syndrome (FBSS). However, a subgroup of patients may become refractory to the effects of conventional waveforms over time. The objective of this study was to systematically review and evaluate the current literature on the use of novel waveform spinal cord stimulation for the management of FBSS refractory to conventional SCSs.
METHODS: A comprehensive electronic search of the literature published in electronic databases, including Ovid MEDLINE and Epub Ahead of Print, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus, was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The outcomes of interest were reduction in back pain and/or leg pain after conversion from conventional to novel SCSs. Risk of bias was assessed with the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool. The strength of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria.
RESULTS: A total of 6 studies with 137 patients with FBSS were identified. Studies were published between 2013 and 2021. The mean ± SD age of the pooled patient sample was 55 ± 10.5 years. All patients who underwent treatment with conventional SCSs were identified. Two studies evaluated the efficacy of high-density spinal cord stimulation, 3 studies evaluated burst spinal cord stimulation, and 1 study assessed multimodal waveforms. The mean difference in back pain scores after conversion from a standard SCS to a novel waveform SCS was 2.55 (95% CI 1.59-4.08), demonstrating a significant reduction in back pain after conversion to novel stimulation. The authors also performed a subgroup analysis to compare burst stimulation to tonic waveforms. In this analysis, the authors found no significant difference in the average reductions in back pain between the 2 groups (p = 0.534).The authors found an I2 statistic equivalent to 98.47% in the meta-regression model used to assess the effect of follow-up duration on study outcome; this value implied that the variability in the data can be attributed to the remaining between-study heterogeneity. The overall certainty was moderate, with a high risk of bias across studies.
CONCLUSIONS: Rescue therapy with novel waveform spinal cord stimulation is a potential option for pain reduction in patients who become refractory to conventional SCSs. Conversion to novel waveform SCSs may potentially mitigate expenses and complications.

Spinal cord stimulation (SCS) is an effective and validated treatment to address chronic refractory neuropathic pain in persistent spinal pain syndrome-type 2 (PSPS-T2) patients. Surgical SCS lead placement is traditionally performed under general anesthesia due to its invasiveness. In parallel, recent works have suggested that awake anesthesia (AA), consisting of target controlled intra-venous anesthesia (TCIVA), could be an interesting tool to optimize lead anatomical placement using patient intra-operative feedback. We hypothesized that combining AA with minimal invasive surgery (MIS) could improve SCS outcomes. The goal of this study was to evaluate SCS lead performance (defined by the area of pain adequately covered by paraesthesia generated via SCS), using an intraoperative objective quantitative mapping tool, and secondarily, to assess pain relief, functional improvement and change in quality of life with a composite score. We analyzed data from a prospective multicenter study (ESTIMET) to compare the outcomes of 115 patients implanted with MIS under AA (MISAA group) or general anesthesia (MISGA group), or by laminectomy under general anesthesia (LGA group). All in all, awake surgery appears to show significantly better performance than general anesthesia in terms of patient pain coverage (65% vs. 34-62%), pain surface (50-76% vs. 50-61%) and pain intensity (65% vs. 35-40%), as well as improved secondary outcomes (quality of life, functional disability and depression). One step further, our results suggest that MISAA combined with intra-operative hypnosis could potentialize patient intraoperative cooperation and could be proposed as a personalized package offered to PSPS-T2 patients eligible for SCS implantation in highly dedicated neuromodulation centers.

Persistent Spinal Pain Syndrome Type 2 (PSPS-T2), (Failed Back Surgery Syndrome), dramatically impacts on patient quality of life, as evidenced by Health-Related Quality of Life (HRQoL) assessment tools. However, the importance of functioning, pain perception and psychological status in HRQoL can substantially vary between subjects. Our goal was to extract patient profiles based on HRQoL dimensions in a sample of PSPS-T2 patients and to identify factors associated with these profiles. Two classes were clearly identified using a mixture of mixed effect models from a clinical data set of 200 patients enrolled in \"PREDIBACK\", a multicenter observational prospective study including PSPS-T2 patients with one-year follow-up. We observed that HRQoL was more impacted by functional disability for first class patients (n = 136), and by pain perception for second class patients (n = 62). Males that perceive their work as physical were more impacted by disability than pain intensity. Lower education level, lack of adaptive coping strategies and higher pain intensity were significantly associated with HRQoL being more impacted by pain perception. The identification of such classes allows for a better understanding of HRQoL dimensions and opens the gate towards optimized health-related quality of life evaluation and personalized pain management.

Treatment of patients with failed back surgery syndrome (FBSS) with predominant low back pain (LBP) remains challenging. High-frequency spinal cord stimulation (HF10 SCS) is believed to achieve significant pain reduction. We aimed to evaluate the real-life efficacy of HF-10 SCS in a tertiary spine center. A prospective observational study of all patients with FBSS and predominant LBP who underwent HF-10 SCS surgery was performed between 2016 and 2018. Patients > 18 years with Visual Analogue Scale (VAS) scores of ≥ 5 for LBP and pain duration > 6 months under stable medication were implanted percutaneous under general anesthesia and a trial phase of 7-14 days was accomplished. Primary end point was a successful trial defined as ≥ 50% VAS score reduction for LBP. Thirty-four of 39 (85%) subjects had a successful trial. Fifty-three percent were female and the mean age was 69 years. Median follow-up lasted for 10 months. Devices were removed after a median of 10 months in 5 cases. Remaining 29 patients stated significant VAS score reduction for LBP from 8.1 to 2.9 and VAS for leg pain from 4.9 to 2.2. Twenty-four percent of all patients were able to discontinue their opioids. Eight of 9 patients (89%) with signs of adjacent disc disease and 7 of 10 (70%) patients with hardware failure were successfully implanted with significant VAS reduction for LBP. HF-10 SCS achieves significant pain reduction in most patients with FBSS and predominant LBP. It might be an efficient alternative to revision surgery.

The term failed back surgery syndrome (FBSS) has been criticized for being too unspecific and several studies have shown that a variety of conditions may underlie this label. The aims of the present study were to describe the specific symptoms and to investigate the primary and secondary underlying causes of FBSS in a contemporary series of patients who had lumbar spinal surgery before.
We used a multilevel approach along three different axes defining symptomatic, morphological, and functional pathology dimensions.
Within the study period of 3 years, a total of 145 patients (74 f, 71 m, mean age 51a, range 32-82a) with the external diagnosis of FBSS were included. Disk surgery up to 4 times and surgery for spinal stenosis up to 3 times were the commonest index operations. Most often, the patients complained of low back pain (n = 126), pseudoradicular pain (n = 54), and neuropathic pain (n = 44). Imaging revealed osteochondrosis (n = 61), spondylarthrosis (n = 48), and spinal misalignment (n = 32) as the most frequent morphological changes. The majority of patients were assigned at least to two different symptomatic subcategories and morphological subcategories, respectively. According to these findings, one or more functional pathologies were assigned in 131/145 patients that subsequently enabled a specific treatment strategy.
FBSS has become rather a vague and imprecisely used generic term. We suggest that it should be avoided in the future both with regard to its partially stigmatizing connotation and its inherent hindering to provide individualized medicine.

To investigate the drug release and anti-adhesion effects of a TET (tetrandrine)-loaded PDLLA (poly-DL-lactide) film. Detection of TET release in vitro was carried out by high-performance liquid chromatography (HPLC) every 2 days following immersion of the tetrandrine-loaded PDLLA film in simulated body fluid until the TET content of the eluate could not be detected. For the in vivo test, TET-loaded PDLLA films were implanted into animal laminectomy models and positive and blank control groups were also set up. Postoperative serum tests, and macroscopic and histological analyses at 1, 4, 8, and 12 weeks, were used to assess the effects of the film. Statistical analyses were performed by one-way ANOVA. The drug release of the tetrandrine-loaded PDLLA film in vitro showed two phases with a second release peak. Ultimately, the duration of continuous delivery was up to 66 days and the cumulative delivery rate was up to 93.18%. Scores for the proliferation of epidural scars or adhesion of the dura mater in the test group were much lower than those for the two control groups. Histological analysis revealed the test group had fewer inflammatory cells and fibroblasts, as well as fewer extracellular collagen fibers, and a lower histology score than those of the two control groups at all time points. Tetrandrine-loaded PDLLA film is a novel controlled drug release and anti-adhesion material in vitro and in vivo.

OBJECTIVE: Patients with chronic low back pain, who do not respond to conservative treatment methods, generally undergo surgical revision operations, and sometimes an undesirable condition called failed back surgery syndrome (FBSS) may be inevitable. Hereby, dextrose is one of the regenerative methods that has gained popularity in the treatment of many musculoskeletal problems, and we aimed to present and evaluate the outcomes of 5% dextrose for the treatment of FBSS.
METHODS: It has been designed as a consecutive case series. A total of 79 patients with FBSS, who had minimum 6 months of symptoms and did not respond to 3 months of conservative methods between May 2014 and March 2016, participated in the study. Prolotherapy injections were applied in posterior and lateral approaches. Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were used for the pre- and post-treatment evaluations. Patient satisfaction was assessed with using a 5-point Likert scale by phone contacting.
RESULTS: There was statistically significant difference between repeated VAS and ODI measurements.
CONCLUSIONS: These results may be the first step giving a lead to an undiscovered field. This treatment method should be kept in mind for FBSS patients before giving a decision of revision surgery. These slides can be retrieved under Electronic Supplementary Material.