Utilization of Leads After Permanent Implant in Spinal Cord Stimulator Systems.

OBJECTIVE: The goal of this study was to determine the frequency and clinical indications associated with implantation of single vs. dual percutaneous lead spinal cord stimulator (SCS) systems and to look further into how these leads are utilized for treatment. MATERIALS AND METHODS: A retrospective cohort analysis of all patients undergoing SCS implantation between January 2001 and December 2013 with a minimum of 2 years of clinical follow-up was performed. Number of trial leads and implanted leads was recorded. For patients with dual-lead systems, it was noted if and when the second lead was used, along with the clinical indication for lead activation. RESULTS: In the 259-patient cohort, 15.8% (n = 41) patients underwent placement of a single-lead system, 83.0% (n = 215) underwent placement of a dual-lead system, and 1.2% (n = 3) underwent placement of 3-lead systems. Placement of dual-lead systems was similar among all indication groups. Of those patients with a dual-lead system in place, 88.1% utilized both leads and average time to programming of the second lead was 2.3 months. The most common reason to activate the second lead was inadequate stimulation coverage. Five of the 41 patients with single-lead systems underwent an additional surgery to implant a second lead due to inadequate stimulation with 1 lead. CONCLUSIONS: To our knowledge this is the first descriptive analysis of the frequency of single- and dual-lead SCS systems. This report indicates that dual-lead systems are most often placed and both leads are required for optimal patient therapy.

Ultrasound-guided transversus abdominis plane block vs trigger point injections for chronic abdominal wall pain: a randomized clinical trial.

ABSTRACT: The primary aim of this randomized clinical trial is to investigate the effects of ultrasound-guided transversus abdominis plane (TAP) vs ultrasound-guided trigger point injections (TPIs) on numerical rating scale pain scores at month 3 follow-up in patients with a chronic abdominal wall pain. The primary outcome measure was the difference in mean numeric rating scale pain scores between the TAP and TPI groups at month 3 in an intent-to-treat (ITT) analysis. A total of 60 patients were randomized 1:1 to receive an ultrasound-guided TAP block (n = 30) or an ultrasound-guided TPI (n = 30). No significant group differences in baseline demographic or clinical characteristics were observed. The mean baseline pain score for the TAP and TPI groups was 5.5 and 4.7, respectively. In the ITT analysis at month 3, the between-group difference in pain scores was 1.7 (95% confidence interval, 0.3-3.0) favoring the TPI group. In a secondary per-protocol analysis, the between-group difference in pain scores was 1.8 (95% confidence interval, 0.4-3.2) favoring the TPI group. For the ITT and per-protocol analyses, the group differences in pain scores were consistent with a medium effect size. The main finding of this randomized clinical trial is that adults with chronic abdominal wall pain who received a TPI reported significantly lower pain scores at month 3 follow-up compared with patients who received a TAP block.

Pain medicine fellow neuromodulation surgical skill assessment tool: a pilot.

OBJECTIVE: Spinal cord stimulation (SCS) is an evidence-based therapy for the treatment of refractory pain. Current American College of Graduate Medical Education requirements for pain medicine fellowship graduation include observation of five neuromodulation cases. Matriculating fellows have varying degrees of technical skill, training, and experience. The purpose of this study was to use an innovative skill-based assessment tool using the validated Zwisch scale to evaluate fellow surgical performance during SCS cases. DESIGN: Cross-sectional survey SETTING: Mayo Clinic, Rochester, Minnesota. SUBJECTS: Consultant faculty (10) in the Division of Pain Medicine and pain medicine fellows (5). METHODS: A list of faculty-driven neuromodulation surgical objectives was formed and a rubric was created that focused on technical approach, imaging, epidural access and wound closure. Consultants who perform surgical cases were instructed to use the Zwisch scale as a guide to evaluate fellow surgical performance during a neuromodulation case. Faculty and fellows were surveyed before and after implementation of the tool to determine their satisfaction with use of the skill assessment tool. RESULTS: The consultants reported they were more satisfied, consistent, and efficient with feedback provided to the trainee on every aspect of neuromodulation surgical cases. The improvement was most significant during the fellows' intraoperative skill assessment. The fellows indicated increased satisfaction, improved communication, and increased efficiency of feedback when the tool was utilized. The fellows reported greater intraoperative skill assessment and consistency of feedback provided. CONCLUSIONS: The diverse nature of primary specialty backgrounds observed in pain medicine fellowship training offers a unique opportunity to assess and improve fellow skill and surgical competence in the field of neuromodulation. Both faculty and fellows reported improved satisfaction, consistency and efficiency with feedback provided. Importantly, this pilot project observed that implementation of a skill assessment tool was beneficial for both the faculty and fellow as the feedback received was viewed as strongly beneficial to the educational experience.

Introduction of infection control measures to reduce infection associated with implantable pain therapy devices.

INTRODUCTION: Implantable pain therapy devices for chronic pain include spinal cord stimulators (SCS) and intrathecal drug delivery systems (IDDS). A number of different complications can occur after implantation of these devices, but among the most serious is infection. Based on Centers for Disease Control and Prevention guidelines for prevention of surgical site infection, published literature on infection risk with implantable pain therapy devices, and recommendations from groups within our own our institution, we introduced infection control measures for all patients receiving either SCS or IDDS. METHODS: After approval from the Institutional Review Board, we performed a retrospective review of patients undergoing primary implantation of SCS or IDDS before and after introduction at our institution of safety measures designed to reduce device-related infection. We compared infection incidence and compliance to infection precautions before and after introduction of these measures. RESULTS: Thirty-four SCS or IDDS were implanted before implementation of the infection control measures and 58 were placed after. Five device-related infections occurred. Adherence to most infection precautions improved during the study period, but 100% compliance was seen only with venue used for implantation. Infection incidence declined after introduction of the safety measures, but the reduction was not statistically significant. CONCLUSIONS: Introduction of infection control measures for implantable pain therapy devices improved adherence to most infection precautions in our practice. Lack of specific documentation could have hindered practice surveillance within our group. A tool to document performance of infection control measures would be useful not only as a marker of compliance but could also serve as a reminder to perform certain safety measures.

Interventional modalities to treat cancer-related pain.

Cancer-related pain is a significant cause of morbidity in those affected by both primary and metastatic disease. Although oral, transdermal, and parenteral opioid medications are an integral part of the World Health Organization's analgesic ladder, their use may be limited by side effects. Fortunately, there are advanced interventional pain management strategies effective in reducing pain in the cancer patient while mitigating the aforementioned side effects. Celiac plexus blocks and neurolysis have been proven effective in treating cancers of the abdominal viscera (ie, pancreas). Transversus abdominis plane blocks, neurolysis, and catheter placement can be used to treat cancer pain associated with the abdominal wall. Peripheral nerve blocks and catheter placement at the brachial and lumbosacral plexus or peripheral nerves treat cancer pain associated with the upper and lower limbs, whereas paravertebral and intercostal blocks treat cancer pain associated with the chest wall and ribs. Finally, alternate drug delivery methods such as intrathecal drug delivery systems concentrate medication at central opioid receptors without affecting the peripheral receptors implicated in unwanted side effects. This article provides an overview of these interventions, including indications, contraindications, and potential complications of advanced interventional pain management options available for the treatment of intractable cancer-related pain.

Pain severity is associated with muscle strength and peak oxygen uptake in adults with fibromyalgia.

BACKGROUND: The associations between pain, lower extremity strength, and aerobic conditioning have not been widely investigated in adults with fibromyalgia (FM). The principle objective of this study was to investigate the relationship between pain severity and knee strength in patients seeking treatment for FM. A secondary objective was to investigate the relationship between pain scores and aerobic conditioning. METHODS: Three measures of knee strength (isokinetic extensor, isokinetic flexor, isometric extensor) were quantified in the dominant leg of 69 adults with FM using a dynamometer at speeds of 60 degrees per second (60°/s) and 180°/s. Peak oxygen uptake (VO2) was assessed using a cycle ergometer, and pain was assessed using the pain severity subscale of the Multidimensional Pain Inventory. RESULTS: In univariable linear regression analyses using pain severity as the dependent variable, lesser values of isokinetic knee extensor strength at 60°/s (P=0.041) and 180°/s (P=0.010), isokinetic knee flexor strength at 60°/s (P=0.028) and 180°/s (P=0.003), and peak VO2 uptake (P=0.031) were predictive of greater pain severity scores. In multiple variable linear regression models adjusted for age, sex, body mass index, and opioid use, the following associations retained statistical significance; isokinetic knee extensor strength at 60°/s (P=0.020) and 180°/s (P=0.003), isokinetic knee flexor strength at 60°/s (P=0.015) and 180°/s (P=0.001), and peak VO2 uptake (P=0.014). However, no significant associations were found between pain severity and isometric knee extensor strength. CONCLUSION: The main findings from this study were that lesser values of isokinetic knee strength and peak VO2 uptake were predictive of greater pain severity scores. These results build on the findings of previous investigations, but ongoing research is needed to further characterize the effects of strength and peak VO2 uptake on the pathophysiology of FM.