Treatment of Ulnar Neuropathic Pain with Peripheral Nerve Stimulation: Two Case Reports.

Ulnar neuropathy is a condition that manifests with symptoms of neuropathic pain, numbness, tingling, and even possible motor deficits in the ulnar distribution of the arm. This debilitating painful condition may be refractory to conservative, pharmacologic, and surgical interventions. Peripheral nerve stimulation (PNS) technology has advanced significantly in recent years allowing for conditions such as ulnar neuropathy to be treated in a minimally invasive manner. Here we report the first case reports in the literature (to our knowledge) of two patients with intractable ulnar neuropathy who underwent minimally invasive PNS Bioventus implants. Both patients experienced at least 75% pain relief based on NRS scores at 6 months after ulnar nerve PNS implantation. The patients also experienced significant improvement in functional outcomes, including return to employment, ability to perform activities of daily living without any impairment, and improved quality of life measures. While the results presented in our two case reports are promising, we only provide observational data over a 6 to 15-month period post-implantation. Future well-powered, large-scale, and long-term randomized controlled trials are warranted to determine efficacy and long-term pain and functional outcomes from PNS therapy for treatment of ulnar neuropathy.

Incidence of Temporary Peripheral Nerve Stimulator Lead Tip Retention: A Retrospective Review of 80 Lead Placements.

OBJECTIVES: The primary objective of this study was to determine the current rate of lead fracture during temporary percutaneous peripheral nerve stimulator (PNS) lead removal at the Mayo Clinic Rochester Division of Pain Medicine. MATERIALS AND METHODS: A retrospective review of electronic medical records was performed for patients implanted with a temporary percutaneous PNS device between January 1, 2018, and December 31, 2020. Patients were included if they underwent temporary percutaneous PNS system implant, with planned lead removal at 60 days. Data collection included date of implant, diagnosis, peripheral nerve target(s), number of leads, and lead tip status at the time of removal (intact vs fractured). RESULTS: Fifty patients underwent a total of 80 temporary percutaneous PNS leads placed during the time frame analyzed. Of the 80 temporary percutaneous PNS leads implanted, there were five lead fractures at the time of intentional lead removal. CONCLUSIONS: This retrospective review of 50 patients with 80 temporary percutaneous PNS leads implanted for chronic peripheral neuropathic pain resulted in a 6.25% rate of retained lead fragment at the time of lead removal by the provider at the end of 60-day treatment. This fracture and retention rate is consistent with previous published retrospective data on PNS, which has shown a 3% to 21% lead fracture rate during intentional lead removal.

Is Response to a Pre-implant Diagnostic Peripheral Nerve Block Associated With Efficacy After Peripheral Nerve Stimulation Implantation? A Ten-Year Enterprise-Wide Analysis.

OBJECTIVES: This study aimed to assess whether patient response to targeted diagnostic peripheral nerve block before peripheral nerve stimulator (PNS) device implantation is associated with efficacy after PNS implantation. MATERIALS AND METHODS: The electronic medical records from the Mayo Clinic Enterprise (three quarternary care medical centers and additional satellite medical centers) were reviewed to identify patients who underwent PNS implantation between January 2014 and January 2023. A primary outcome of interest was to assess whether administration of a preimplant diagnostic peripheral nerve block predicted pain relief at three months and six months after temporary and permanent PNS implantation. Another primary outcome was to investigate whether there was an association between the pain relief from a preimplant diagnostic peripheral nerve block and pain relief after three and six months after temporary or permanent PNS therapy. Linear regression analysis was conducted for outcomes of interest. RESULTS: Of 193 eligible patients who underwent PNS therapy, a total of 173 patients were included in the final analysis and were stratified into either the temporary PNS cohort (n = 112) or the permanent PNS cohort (n = 61). Overall, 77.5% of all patients (134/173) underwent a preimplant diagnostic peripheral nerve block and reported a mean percentage relief of 70.1 ± 27.0 from the diagnostic block. Of patients in the temporary PNS cohort, there was no difference in postimplant percentage pain relief between patients who received a diagnostic block (n = 93) and control patients (n = 19) at three months (35.4 ± 36.0 vs 49.8 ± 36.1, respectively; ß -14.45, 95% CI -32.98 to 4.07, p = 0.125) or at six months (23.3 ± 30.8 vs 45.7 ± 40.0, respectively; ß -22.39, 95% CI -46.86 to 2.08, p = 0.072). Of patients in the permanent PNS cohort, there was no difference in postimplant percentage pain relief between patients who received a diagnostic block (n = 41) and control patients (n = 20) at three months (42.4 ± 34.3 vs 43.2 ± 42.4, respectively; ß -0.79, 95% CI -23.56 to 21.99, p = 0.945) or at six months (44.3 ± 35.0 vs 38.8 ± 40.9, respectively; ß 5.42, 95% CI -20.04 to 30.88, p = 0.669). Pain relief from preimplant diagnostic blocks was associated with postimplant pain relief from temporary PNS at three months (ß 0.33, 95% CI 0.04-0.61, p = 0.025). However, pain relief from preimplant diagnostic blocks did not predict postimplant pain relief from temporary PNS at six months, or permanent PNS at three months and six months. CONCLUSIONS: Administration of a diagnostic block is not associated with superior pain relief at three or six months after PNS implantation to that of an approach without diagnostic block. Pain relief from a diagnostic block may potentially predict short-term pain relief after temporary PNS therapy, although future prospective studies are warranted to evaluate the prognostic utility of diagnostic blocks.

Perioperative Opioid Consumption and Clinical Outcomes in Surgical Patients With a Pre-existing Opioid-Based Intrathecal Drug Delivery System.

BACKGROUND: Intrathecal drug delivery systems (IDDS) have been utilized for over 3 decades for management of chronic pain and spasticity. Patients with IDDS may present for surgical procedures unrelated to the IDDS device, although data are limited regarding perioperative outcomes. METHODS: This is a historical matched cohort study conducted between January 1, 2007 and December 31, 2016 of patients with an opioid-based IDDS versus matched control patients undergoing surgery excluding interventional pain procedures. Patients in the IDDS group were matched with up to 2 patients without an IDDS. Multivariable regression analyses were utilized to assess differences in the primary outcome of cumulative perioperative opioid consumption (ie, intraoperative and postanesthesia care unit [PACU] opioid consumption), and opioid consumption during the first 24 and 72 postoperative hours. Postoperative clinical outcomes were also assessed including escalating oxygen requirements, naloxone administration, pain-sedation mismatch, and perioperative pain service consultation. RESULTS: A total of 321 surgeries were included, 112 with IDDS and 209 controls, with median (interquartile range [IQR]) age of 57 (49-64) years. Compared to matched controls, patients with an IDDS had greater perioperative opioid consumption (median [IQR] oral morphine milligram equivalents [OME] of 110 [60-163] vs 93 [IQR, 53-142]; adjusted multiplicative increase 1.28 [95% confidence interval {CI}, 1.03-1.59]; P = .026). IDDS patients also had greater opioid consumption in the first 24 and 72 postoperative hours (multiplicative increases of 2.23 [95% CI, 1.36-3.63], P = .001, and 2.46 [95% CI, 1.41-4.32], P = .002, respectively). There were no significant differences in postoperative oxygen requirements, naloxone administration, or pain-sedation mismatch. Inpatient pain medicine consultation was more frequent in IDDS patients compared to controls (51.8% vs 6.2%; P < .001). CONCLUSIONS: Patients with opioid-based IDDS received more perioperative opioids and were more likely to receive postoperative pain service consultation compared to matched controls. There were no significant differences in clinical safety outcomes, suggesting tolerance for higher opioid doses. Further research is warranted to optimize perioperative outcomes in those with IDDS.

Peripheral Nerve Stimulation: A New Treatment for Meralgia Paresthetica.

BACKGROUND: Meralgia paresthetica is a condition caused by entrapment of the lateral femoral cutaneous nerve that leads to paresthesia along the anterolateral portion of the thigh. Because of advancements in neuromodulation, peripheral nerve stimulation (PNS) has been considered a new treatment option for meralgia paresthetica. Newer PNS technology targets peripheral nerves directly yet in a minimally invasive manner. We report a case in which a PNS device provided more than 12 months of complete pain relief in a patient with meralgia paresthetica and helped the patient avoid a neurolysis procedure. CASE PRESENTATION: A 57-year-old male presented to clinic with a 6-year history of "painful numbness [and] burning" along the right lateral thigh. He rated his pain as 8 out of 10, which decreased to a rating of 2 out of 10 with the use of gabapentin, but unwanted side effects motivated him to seek alternative treatment. On the basis of his history, physical exam, and imaging results, he was diagnosed with meralgia paresthetica. He was offered neurolysis; however, after seeing a pain specialist, he agreed to the implantation of a SPRINT peripheral nerve stimulator. After the implantation procedure, his pain reduced to 0 out of 10, and his quality of life improved, with better sleep and less somnolence. The device was removed after 60 days, as planned. He continued to have complete resolution of pain at 12 months after the date of device implantation. CONCLUSION: With recent advancements, PNS can be used to treat meralgia paresthetica in an effective yet minimally invasive manner. As newer PNS technology becomes more familiar to physicians and pain specialists, it is likely to be used as a mainstay treatment for meralgia paresthetica.

The Use of the Seattle Angina Questionnaire in Patients Who Underwent Spinal Cord Stimulation for Refractory Angina Pectoris.

BACKGROUND: The Seattle Angina Questionnaire (SAQ) is a self-administered questionnaire used in cardiac patients to quantify angina based on five scales: physical limitation scale, anginal stability scale, anginal frequency scale, treatment satisfaction scale, and the disease perception scale. Here we report the use of the SAQ to assess angina symptoms in 18 patients who underwent spinal cord stimulation (SCS) for refractory angina pectoris (RAP) at the Mayo Clinic. METHODS: Electronic health records were searched to find patients who underwent SCS for the treatment of RAP at a single institution from 2003 to 2018. Eligible patients were asked to participate in a phone survey that included the SAQ. RESULTS: Out of 13 patients who still had their implant, six (46%) had minimal physical limitations. Ten patients (76.9%) had favorable anginal frequency scores, defined as minimal or mild. Out of the five patients who had their device removed, one (20%) had minimal physical limitations and three (60%) had favorable anginal frequency scores. There was a high treatment satisfaction score for both those with their implant in place and those with the device removed. CONCLUSION: The SAQ is useful as a comprehensive measure specific to patients with RAP assessing function, pain, and satisfaction. The utilization of this tool pre- and post-operatively may provide additional information to analyze the effectiveness of SCS for RAP.

Pre-Operative Assessment of Patients Undergoing Spinal Cord Stimulation for Refractory Angina Pectoris.

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.

Peripheral Nerve Stimulation and Clinical Outcomes: A Retrospective Case Series.

PURPOSE: Peripheral nerve stimulation (PNS) is a rapidly expanding field within neuromodulation; however, there is limited data on therapeutic efficacy. This study describes the indications and clinical outcomes for patients undergoing PNS for chronic pain states. PATIENTS AND METHODS: This is a retrospective case series of adults undergoing PNS implantation from 2004 to 2017 at an academic medical center. The primary outcomes were changes in numeric rating scale (NRS) pain scores, opioid utilization in oral morphine milligram equivalent (MME), and self-reported patient functioning at 6 months postoperatively. Infectious and device-related complications were also assessed. RESULTS: A total of 72 patients underwent PNS implantation, including 59 patients that received a preceding PNS trial (59/78; 76% progression rate) and 13 that did not receive a PNS trial. The most common indication for stimulation was occipital neuralgia (47%) followed by lower-extremity neuropathies (17%). PNS implantation was associated with 6-month reductions in pain scores (7 [6, 8] baseline vs. 4 [2, 5] 6 months; P < 0.001) and opioid utilization (eg, median 60 [31, 104] vs. 18 [0, 52] MME among those with baseline opioid use; P < 0.001). Median functional improvement was 73% (50%, 88%). Seven patients (10%) suffered a postoperative surgical site infection at a median of 50 (30, 124) days, of which five devices were removed. CONCLUSION: Peripheral nerve stimulation was associated with reduced pain scores, lower opioid utilization, and improved patient function at 6 months. These data support PNS as a potentially effective nonopioid analgesic modality in chronic pain, though prospective multicenter evaluation is warranted to evaluate longer-term outcomes.

Advancement in Neuromodulation Technology with the Innovation of Design-Specific Peripheral Nerve Stimulators: Sural Nerve Stimulation for Radiculopathy.

BACKGROUND: Peripheral nerve stimulation (PNS) is a form of neuromodulation that is used to treat chronic and refractory neuropathic pain. Peripheral nerve stimulation was first described in the early 1960s when Shelden implanted a PNS device for trigeminal neuralgia. Despite PNS being known since the 1960s, technology designed specifically for PNS was lacking. Within the past few years, design-specific PNS devices have become widely available, with favorable efficacy and safety profiles. Here we report a case of design-specific PNS that provided two years of pain relief in a patient with lower extremity neuropathic pain. CASE PRESENTATION: A 53-year-old female with a history of congenital lumbar meningocele status post-L4-L5 laminectomy presented to the Mayo Clinic for treatment of foot pain that began three days after her laminectomy. She experienced a 6/10 burning, tingling sensation in the lateral dorsal portion of her right foot and posterolateral calf in addition to allodynia that prevented her from wearing shoes. She failed gabapentin, amitriptyline, cannabis, transforaminal epidural steroid injections, and two spinal cord stimulator trials. The patient ultimately underwent implantation of a right sural nerve stimulator, resulting in a 50% improvement in pain and functionality at two-year follow-up. CONCLUSIONS: This report emphasizes the recent development of design-specific PNS devices and their successful use in this patient. Peripheral nerve stimulation technology and applications have diminished the role of spinal cord stimulation devices used for the periphery. Peripheral nerve stimulation should be considered for patients with isolated extremity pain, especially in those with spinal abnormalities (e.g., arachnoid cyst).

Fibromyalgia Symptom Severity and Psychosocial Outcomes in Fibromyalgia Patients with Hypovitaminosis D: A Prospective Questionnaire Study.

OBJECTIVE: To evaluate the association between hypovitaminosis D and outcomes of symptom severity, mood disorders, fatigue, and quality of life in fibromyalgia (FM) patients. METHODS: Five hundred ninety-three FM patients were surveyed from May 2012 to November 2013. Patients with serum vitamin D <25 ng/mL were considered to have hypovitaminosis D. The primary outcome was FM symptom severity (FIQ-R questionnaire). Secondary outcomes included quality of life (SF-36), fatigue (MFI-20), anxiety (GAD-7), and depression (PHQ-9). Independent t tests and chi-square tests were performed for continuous and categorical variables, respectively. Regression analysis was performed adjusting for age, gender, body mass index, ethnicity, and season. A post hoc analysis examined for correlation between outcomes and serum vitamin D (ng/mL) as a continuous variable. RESULTS: One hundred twenty-two patients (20.6%) had hypovitaminosis D. In our adjusted regression analysis, the total FIQ-R score in patients with hypovitaminosis D was higher compared with control patients with adequate serum vitamin D (57.85 ± 18.09 vs 62.79 ± 18.10, P = 0.04). Adjusted regression analysis revealed higher total GAD-7 (P = 0.01) and higher total PHQ-9 scores (P = 0.04) in patients with hypovitaminosis D compared with control patients. There were no differences based on severity of depression or anxiety. No differences in fatigue or quality of life were identified. Unadjusted post hoc analysis revealed that as serum vitamin D increased, there was an association with lower total FIQ-R (ß coefficient = -0.11, P = 0.02) and lower SF-36 subscale scores of role-physical (ß coefficient = -0.10, P = 0.03). Adjusted post hoc analysis revealed no significant associations. CONCLUSIONS: Hypovitaminosis D may be a risk factor for worse symptom severity, anxiety, and depression in FM patients.

Combined Celiac Ganglia and Plexus Neurolysis Shortens Survival, Without Benefit, vs Plexus Neurolysis Alone.

BACKGROUND & AIMS: Pancreatic cancer produces debilitating pain that opioids often ineffectively manage. The suboptimal efficacy of celiac plexus neurolysis (CPN) might result from brief contact of the injectate with celiac ganglia. We compared the effects of endoscopic ultrasound-guided celiac ganglia neurolysis (CGN) vs the effects of CPN on pain, quality of life (QOL), and survival. METHODS: We performed a randomized, double-blind trial of patients with unresectable pancreatic ductal adenocarcinoma and abdominal pain; 60 patients (age 66.4±11.6 years; male 66%) received CPN and 50 patients (age 66.8±10.0 years; male 56%) received CGN. Primary outcomes included pain control and QOL at week 12 and survival (overall median and 12 months). Secondary outcomes included morphine response, performance status, secondary neurolytic effects, and adverse events. RESULTS: Rates of pain response at 12 weeks were 46.2% for CGN and 40.4% for CPN (P = .84). There was no significant difference in improvement of QOL between the techniques. The median survival time was significantly shorter for patients receiving CGN (5.59 months) compared to (10.46 months) (hazard ratio for CGN, 1.49; 95% CI, 1.02-2.19; P = .042), particularly for patients with non-metastatic disease (hazard ratio for CGN, 2.95; 95% CI, 1.61-5.45; P < .001). Rates of survival at 12 months were 42% for patients who underwent CPN vs 26% for patients who underwent CGN. The number of adverse events did not differ between techniques. CONCLUSION: In a prospective study of patients with unresectable pancreatic ductal adenocarcinoma and abdominal pain, we found CGN to reduce median survival time without improving pain, QOL, or adverse events, compared to CPN. The role of CGN must be therefore be reassessed. Clinicaltrials.gov no: NCT01615653.

Office-Based Mesenchymal Stem Cell Therapy for the Treatment of Musculoskeletal Disease: A Systematic Review of Recent Human Studies.

BACKGROUND: The use of mesenchymal stem cells (MSCs) in clinical applications for the treatment of musculoskeletal disease is steadily increasing in office-based practice. The so-called "first generation" of MSCs is defined as autologous stem cells that have undergone minimal manipulation and are used for a homologous purpose. Systematic reviews of the clinical trials completed to date of such MSCs enable practitioners to better understand what is currently known about the outcomes and side effects of such treatments. STUDY DESIGN: A systematic review of human clinical studies of office-based MSC therapy for the treatment of painful degenerative musculoskeletal conditions. METHODS: A search of the Ovid MEDLINE, EMBASE, and Scopus databases was conducted from 2006 through September 2016. Seven hundred sixty-one records were identified from database searching, and two records from reference review of included papers. Studies with human subjects that evaluated treatment of musculoskeletal disease with minimally manipulated MSCs were included. RESULTS: Eight studies were included in this review based on selection criteria. A total of 941 patients were included, 841 of whom received cellular products, and no significant adverse events were reported. Symptomatology generally improved, though no differences were seen over controls where present. CONCLUSION: Support in the literature is strongest for the use of bone marrow aspirate concentrate (BMAC) injections for the treatment of knee pain, but applications of the use of BMAC and peripheral blood-derived MSCs for the treatment of hip pain, tendon pain, and disc pain have all been reported. Further research is required, with large randomized controlled trials.

Bleeding Complications in Patients Undergoing Intrathecal Drug Delivery System Implantation.

INTRODUCTION: Intrathecal drug delivery systems (IDDSs) have dramatically improved analgesia and the functional status of cancer patients and those with chronic pain states. However, given the close proximity to the neuraxis and frequent concomitant use of antiplatelet or anticoagulant medications, this intervention is not without risk. The goal of this investigation was to determine the incidence of bleeding complications following IDDS placement. METHODS: This is a retrospective review from 2005 through 2014 of adult patients undergoing IDDS implantation or revision at a tertiary care center. The primary outcome was a bleeding-related neurological complication requiring emergency medicine, neurology, or neurosurgical evaluation within 31 days. RESULTS: A total of 247 procedures were performed on 216 unique patients. Patients received aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) within seven days of needle placement for 64 procedures (25.9%). A preprocedural platelet count or international normalized ratio (INR) was available within 30 days for 138 procedures (55.9%). Of these, two patients had a platelet count lower than 100 x 109/L and one patient had an INR of 1.5 or higher at the time of the procedure. One neurological complication was identified (0.4%) that was not related to procedural bleeding. Similarly, three patients (1.2%) received a periprocedural red blood cell transfusion, none of which were related to procedural bleeding. CONCLUSION: No cases of bleeding-related neurological complications were identified following IDDS placement or revision, including in those receiving aspirin or NSAIDs. Future investigations with larger numbers are needed to further explore the safety of antithrombotic therapy continuation or discontinuation periprocedurally.

Safety of Lumbar Spine Radiofrequency Procedures in Patients Who Have Posterior Spinal Hardware.

OBJECTIVE: The purpose of this study was to determine whether the energy generated by an active radiofrequency (RF) cannula adjacent to lumbar spine hardware could result in heating of the hardware. DESIGN: Prospective study. SETTING: Tertiary care medical center. SUBJECTS: Six patients with lumbar facet joint pain at the level adjacent to lumbar spine fusion hardware were studied. METHODS: A total of 10 lumbar medial branch nerve radiofrequency lesion procedures were performed on six patients. A temperature probe was placed on the fusion hardware to continuously monitor the temperature of the hardware throughout the RF procedure. RESULTS: The temperature of the fusion hardware increased in six of the 10 RF lesion procedures. During two of the procedures, the temperature rose rapidly to 42°C, at which time the procedure was ceased at that level. CONCLUSION: This study demonstrated that radiofrequency lesioning to treat symptomatic facet joint pain in patients who have adjacent posterior lumbar fusion hardware may result in heat energy being transferred to the adjacent hardware. This may increase the risk of injury to the patient. Monitoring for a temperature increase is easily accomplished by inserting a temperature probe onto the surface of the hardware.

Bleeding Complications in Patients Undergoing Percutaneous Spinal Cord Stimulator Trials and Implantations.

INTRODUCTION: Spinal cord stimulators (SCS) are indicated for the management of multiple pain states with strong evidence. Recent guidelines recommend discontinuing aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) for the described procedures. The goal of this investigation is to assess the rate of bleeding and neurologic sequelae in patients undergoing SCS trials and implantation. METHODS: This is a retrospective review from 2005 through 2014 of all patients 18 years or older undergoing the following procedures: Percutaneous SCS implantations, SCS revisions, and SCS trials. Baseline characteristics, antiplatelet and anticoagulation medications, coagulation parameters, and procedural details were extracted. The primary outcome was the presence of a bleeding complication within 31 days of the procedure requiring emergency medicine, neurology, or neurosurgical evaluation. The neurological complication was independently categorized for its potential relationship to procedural bleeding, and periprocedural red blood cell transfusion requirements were analyzed as a secondary outcome. RESULTS: A total of 642 percutaneous SCS procedures were performed on 421 unique patients, including 346 SCS trials, 255 SCS implantations, and 41 revision surgeries. Patients had received aspirin or NSAIDs within 7 days of needle placement for 101 procedures (15.7%). There were no bleeding or neurological complications identified in this cohort. CONCLUSION: Although the incidence of epidural hematoma is low, the development of bleeding complications following SCS lead placement can be devastating. In the present investigation, we identified no cases of epidural hematoma following percutaneous SCS lead placement, including more than 100 patients receiving aspirin or NSAIDs. Future investigations with larger numbers are needed to better define the relationships between periprocedural aspirin and NSAID utilization and bleeding complications.

Incidence of clinically significant percutaneous spinal cord stimulator lead migration.

OBJECTIVE: To examine the incidence of percutaneous spinal cord stimulator lead migration, given current hardware and surgical technique. MATERIALS AND METHODS: We retrospectively reviewed records of patients who underwent spinal cord stimulator implantation with percutaneous leads at our institution from 2008 through 2011. We determined the number of patients who required surgical revision for clinically significant lead migration. RESULTS: Clinically significant lead migration requiring surgical revision occurred in three of 143 patients (2.1%) with primary SCS system implants utilizing percutaneous-type leads. CONCLUSIONS: The rate of lead migration observed in our practice was considerably lower than previously published estimates of clinically significant lead migration or revision for lead migration (13%-22%). However, our study did not determine the reason for the decreased rate, which may be influenced by current hardware and implant techniques.

Potential Cost Savings with 60-day Peripheral Nerve Stimulation Treatment in Chronic Axial Low Back Pain.

INTRODUCTION: Chronic axial low back pain (CLBP) that is not responsive to medication management or physical therapy often requires significant clinical intervention. Several interventional pain management options exist, including a 60-day peripheral nerve stimulation (PNS) treatment. This economic evaluation investigated the potential for projected cost savings associated with prioritizing 60-day PNS treatment relative to a 'standard of care' (SOC) approach (where patients do not have access to 60-day PNS). METHODS: A decision tree (supervised machine learning) model tracked treatment progression across two hypothetical cohorts of US patients with CLBP in whom non-interventional options were ineffective (Cohort A: treatment starting with 60-day PNS followed by any additional interventional and surgical treatments versus Cohort B: standard of care interventional and surgical treatments without access to 60-day PNS). Treatment efficacy estimates were based on published success rates. Conditional on treatment failure, up to two additional interventions were considered within the 12-month time frame in both cohorts. SOC treatment options included epidural injection, radiofrequency ablation (RFA), basivertebral nerve ablation (BVNA), PNS permanent implant (PNS-PI), spinal cord stimulator (SCS) trial/implant, and spinal fusion surgery. Treatment choice probabilities in both cohort algorithms were based on clinician interviews. Costs were based on national Medicare reimbursement levels in the ambulatory surgery center (ASC) setting. Savings reflected the difference in projected costs between cohorts. A Monte Carlo simulation and sensitivity analyses were conducted to generate confidence intervals and identify important inputs. RESULTS: The treatment algorithm which prioritized initial 60-day PNS treatment was projected to save $8056 (95% CI $6112-$9981) per patient during the first year of interventional treatment relative to the SOC approach. CONCLUSIONS: Use of the 60-day PNS treatment as an initial interventional treatment in patients with CLBP may result in significant savings for Medicare. Projected savings may be even larger for commercial payers covering non-Medicare patients.

Preoperative gabapentin for acute post-thoracotomy analgesia: a randomized, double-blinded, active placebo-controlled study.

BACKGROUND: The role of preoperative gabapentin in postoperative pain management is not clear, particularly in patients receiving regional blockade. Patients undergoing thoracotomy benefit from epidural analgesia but still may experience significant postoperative pain. We examined the effect of preoperative gabapentin in thoracotomy patients. METHODS: Adults undergoing elective thoracotomy were enrolled in this prospective, randomized, double-blinded, placebo-controlled study, and randomly assigned to receive 600 mg gabapentin or active placebo (12.5 mg diphenhydramine) orally within 2 hours preoperatively. Standardized management included thoracic epidural infusion, intravenous patient-controlled opioid analgesia, acetaminophen and ketorolac. Pain scores, opioid use and side effects were recorded for 48 hours. Pain was also assessed at 3 months. RESULTS: One hundred twenty patients (63 placebo and 57 gabapentin) were studied. Pain scores did not significantly differ at any time point (P = 0.53). Parenteral and oral opioid consumption was not significantly different between groups on postoperative day 1 or 2 (P > 0.05 in both cases). The frequency of side effects such as nausea and vomiting or respiratory depression was not significantly different between groups, but gabapentin was associated with decreased frequency of pruritus requiring nalbuphine (14% gabapentin vs. 43% control group, P < 0.001). The frequency of patients experiencing pain at 3 months post-thoracotomy was also comparable between groups (70% gabapentin vs. 66% placebo group, P = 0.72). CONCLUSIONS: A single preoperative oral dose of gabapentin (600 mg) did not reduce pain scores or opioid consumption following elective thoracotomy, and did not confer any analgesic benefit in the setting of effective multimodal analgesia that included thoracic epidural infusion.

Comparative Effectiveness of Landmark-guided Greater Occipital Nerve (GON) Block at the Superior Nuchal Line Versus Ultrasound-guided GON Block at the Level of C2: A Randomized Clinical Trial (RCT).

OBJECTIVES: The purpose of this single center, prospective randomized controlled trial was to compare clinical outcomes between an ultrasound-guided greater occipital nerve block (GONB) at the C2 vertebral level versus landmark-based GONB at the superior nuchal line. METHODS: Patients with occipital neuralgia or cervicogenic headache were randomized to receive either a landmark-based GONB with sham ultrasound at the superior nuchal line or ultrasound-guided GONB at the C2 vertebral level with blinding of patients and data analysis investigators. Clinical outcomes were assessed at 30 minutes, 2 weeks, and 4 weeks postinjection. RESULTS: Thirty-two patients were recruited with 16 participants in each group. Despite randomization, the ultrasound-guided GONB group reported higher numeric rating scale (NRS) scores at baseline. Those in the ultrasound-guided GONB group had a significant decrease in NRS from baseline compared with the landmark-based GONB group at 30 minutes (change of NRS of 4.0 vs. 2.0) and 4-week time points (change of NRS of 2.5 vs. -0.5). Both groups were found to have significant decreases in Headache Impact Test-6. The ultrasound-guided GONB had significant improvements in NRS, severe headache days, and analgesic use at 4 weeks when compared with baseline. No serious adverse events occurred in either group. CONCLUSIONS: Ultrasound-guided GONBs may provide superior pain reduction at 4 weeks when compared with landmark-based GONBs for patients with occipital neuralgia or cervicogenic headache.