Citations

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

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.

Abstract There is great interest in expanding the use of ultrasound (US), but new challenges exist with its application to lumbar facet–targeted procedures. The primary aim of this systematic review and meta-analysis was to determine the risk of incorrect needle placement associated with US–guided lumbar medial branch blocks (MBB) and facet joint injections (FJI) as confirmed by fluoroscopy or computerized tomography (CT). An a priori protocol was registered, and a database search was conducted. Inclusion criteria included all study types. Risk of bias was assessed using the Cochrane risk of bias tool for randomized controlled trials and the National Heart, Lung, and Blood tool for assessing risk bias for observational cohort studies. Pooled analysis of the risk difference (RD) of incorrect needle placement was calculated. Pooled analysis of 7 studies demonstrated an 11% RD (P < 0.0009) of incorrect needle placement for US-guided MBB confirmed using fluoroscopy with and without contrast. Pooled analysis of 3 studies demonstrated a 13% RD (P < 0.0001) of incorrect needle placement for US-guided FJI confirmed using CT. The time to complete a single-level MBB ranged from 2.6 to 5.0 minutes. The certainty of evidence was low to very low. Ultrasound-guided lumbar MBB and FJI are associated with a significant risk of incorrect needle placement when confirmed by fluoroscopy or CT. The technical limitations of US and individual patient factors could contribute to the risk of incorrect needle placement.

Abstract Background Neuropathic pain is a complex condition that can be refractory to conventional management and can cause persistent suffering in patients. Current pharmacologic treatments can provide temporary symptomatic relief; however, the mechanism of these therapies does not address the underlying cause of neuropathic pain. The use of injectable biologics for neuropathic pain has multiple proposed mechanisms for analgesia including attenuation of inflammatory mediated processes, arrest or delay of the degenerative process, inhibition of apoptotic pathways, and augmentation of the survival and recovery of injured and uninjured nerves. Study Design A systematic review of human studies involving the use of injectable biologics for neuropathic pain. Methods A comprehensive search of several data bases including Ovid MEDLINE ® and Epub Ahead of Print, In Process & Other Non-Indexed Citations and Daily, and Ovid Embase from inception to November 24, 2020. Results The initial search yielded 3,450 studies with an additional 6 studies identified through other resources. Twenty-seven studies were included after independent review by two of the investigators. The included studies assessed the efficacy of injectable biologics for the treatment of neuropathic pain defined as pain reduction. Secondary outcome measures included functional improvement as well as safety of the procedures. A qualitative assessment of the literature without meta-analysis was performed due to the heterogeneity of the data. Conclusion According to the GRADE criteria, there is very low certainty of evidence in support of the efficacy of injectable biologics for treatment of neuropathic pain. Future efforts should focus on creating a standardized methodology and study design with respect to preparation, dosage and route of administration of biologics. This will serve as a catalyst for higher quality randomized trials with generation of more useful data to help drive informed clinical decision making.

Abstract Spinal cord stimulation (SCS) is used to treat a variety of chronic pain conditions refractory to more conservative management including refractory angina pectoris. We identified 31 patients who underwent SCS implantation for the indication of refractory angina at a single institution from 2003 through 2018. Sixteen patients were male, and 15 were female. Average age was 53.9 years. Prior to SCS implantation, all patients had at least one coronary angiogram. Ten (32.3%) patients had undergone percutaneous coronary intervention, and four (12.9%) had undergone coronary artery bypass grafting. Thirty patients (96.7%) were currently using anti-angina medications. Twenty-six patients (83.9%) were on antiplatelet or anticoagulant agents at the time of SCS evaluation. Spinal cord stimulation implanters must perform a comprehensive evaluation incorporating appropriate multidisciplinary care particularly in patients with refractory angina given their cardiovascular comorbidities. It is important to have baseline data (e.g., pain scores, nitroglycerin consumption, frequency of angina episodes, and a questionnaire, such as the Seattle Angina Questionnaire) to compare with follow-up data to help define treatment success. We report a single institution’s pre-operative experience for patients undergoing SCS for refractory angina to illustrate unique pre-operative SCS considerations in this chronic pain population.