Pittelkow, Thomas P.

Abstract Objective Low back pain (LBP) is a leading cause of pain and disability worldwide. Recent studies demonstrate a vertebrogenic model involving the basivertebral nerve (BVN) as a cause of chronic LBP. Vertebral endplates are highly innervated by the BVN, and literature shows type 1 and 2 Modic changes at vertebral endplates are a source of vertebrogenic low back pain (VBP). As a result, intraosseous radiofrequency ablation of the BVN is a minimally invasive outpatient procedure used to treat VBP. We conducted a retrospective review of 1,145 patients that have undergone BVN ablation to assess for safety and complication management. Methods Chart reviews were conducted to obtain demographic and pre-procedural information regarding patient gender, age at the time of BVN ablation, duration of LBP, and BMI. Post-procedure information derived from chart notes included vertebral levels ablated and post-BVN ablation complications, which were categorized as increased LBP > 7 days, increased radicular pain > 7 days, lower extremity weakness, infection, vertebral compression fracture, superficial bleeding, spinal or epidural hematoma, serious neurological injury, visit to the ER, and deep vein thrombosis/clot. Results 1,145 patient charts were reviewed showing an overall complication rate of 3.2% (37 complications). Increased radicular pain was the most common complication at 2.2% (25 complications) and resolved completely in all but one patient. The overall complication rate fell to 1.1% (13 complications) when the 24 cases of transient radicular pain were not counted as adverse events. Conclusions In this multicenter retrospective review, the overall rate of complications related to BVN ablation was low (3.2%). The most common complication was temporary radicular pain that resolved with conservative care. These findings suggest that BVN ablation is a safe treatment for VBP in real-world clinical settings.

Postdural puncture headache is a frequently encountered complication following procedures such as lumbar puncture, neuraxial anesthesia, or intrathecal drug delivery device implantation. It classically presents as a painful orthostatic headache that is exacerbated when a patient is upright. For treatment, patients are often started on conservative options such as hydration, caffeine, bedrest, and NSAID analgesics; however, certain patients who fail these therapies may require intervention with an epidural blood patch. The epidural blood patch remains the gold standard for treating refractory postdural puncture headache. Contraindications to epidural blood patch include severe coagulopathy, patient refusal, or infection at the intended site of entry. There are no clear consensus recommendations regarding patients with a hematological malignancy and potential risk that autologous blood may seed malignant cells into the neuraxis. In this case report, we present a patient with acute myeloid leukemia who developed a postdural puncture headache after receiving subarachnoid administration of antineoplastics. The patient was refractory to conservative therapy, prompting multidisciplinary consultation and discussion with the patient about the risks and benefits of proceeding with an epidural blood patch. Ultimately, the patient elected to proceed with the offered epidural blood patch which led to complete resolution of his painful headaches and did not cause any spread of malignant cells into his neuraxis or cerebral spinal fluid.

Spinal cord and dorsal root ganglion stimulation are minimally invasive surgical techniques used to treat an array of chronic pain disorders. There is a paucity of data related to defining best practices in these specific patient populations, and historically, providers have relied on consensus committees to opine on the best techniques for patient safety and experience. The most efficacious mechanism of surgical closure—specifically a running suture closure compared to a surgical staple closure—is debated. A retrospective review of 155 patients implanted with either a spinal cord or dorsal root ganglion stimulator between 2017 and 2019 was undertaken to determine if the type of surgical closure was related to degree of postoperative surgical site discomfort. The primary outcome showed no statistically significant difference on postoperative pain scores between the suture (6.0 (IQR 5.0–8.0)) and staple (7.0 (IQR 5.0–8.0)) cohorts at postoperative day (POD) #1 (adjusted β 0.17 (95% CI −0.61 to 0.95), P = 0.670 ). This finding held for postoperative pain scores at POD #10 as well (staples (1.0 (IQR 0.0–4.0)) and suture (2.0 (IQR 0.0–5.0), adjusted β −0.39 (95% CI −1.35 to 0.58), P = 0.432 )). A regression analysis was performed to identify secondary factors impacting postoperative pain scores. Higher preoperative pain score (β 0.50 (95% CI 0.09 to 0.92), P = 0.019 ) and female gender (β 1.09 (95% CI 0.15 to 2.02), P = 0.023 ) were predictive of higher incisional pain scores at POD#10. Increasing age was associated with decreased incisional pain scores at POD#10 (β −0.06 (95% CI −0.09 to −0.03), P < 0.001 ). These findings are of interest to the pain practitioner and may be valuable in preoperative discussions with prospective patients.

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.

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.

Abstract Background/Objective Chronic pain is commonly reported in individuals with spinal cord injuries (SCIs), with recent prevalence reported as high as 80%. Uncontrolled pain is known to decrease quality of life, attenuate mood, and impact sleep. Spinal cord stimulation (SCS) for the treatment of refractory pain was first used in the SCI population in 1972. To date there have been no randomized controlled trials examining the effect of SCS on neuropathic pain post‐SCI. A literature review in 2009 identified 27 studies, the majority prior to 2000, that included at least 1 patient with SCI. Given the significant advancements in the field of SCS, this review examines the updated evidence of SCS for the treatment of neuropathic pain in individuals with SCI and provides guidance on future investigations. Methods MEDLINE and EMBASE databases were searched. All published reports, case series, and clinical trials reviewing SCS for neuropathic pain that included at least 1 individual with SCI were included. Results The initial search identified 376 reports, of which 22 met inclusion criteria, for a total of 69 patients. All reports were of very low quality. A majority of the reported patients were male, underwent tonic stimulation, and reportedly experienced improvement in pain and spasticity, with decreased use of pain medication. Conclusions The synthesized findings from primarily case studies support the safety of SCS in SCI with the suggestion of potential pain relief benefit; however, data from low‐quality studies are insufficient for informing clinical practice. A well‐designed, prospective clinical trial is proposed to further investigate this indication.

Background Women are entering medical school in record numbers, but multiple male-dominated medical specialties still exist, including pain medicine. It is not well-understood how gender diversity in academic pain medicine faculty affects fellow matriculation between female and male applicants. Objective We conducted a survey to ascertain whether gender diversity of those in leadership roles in pain medicine programs impacts the gender diversity of fellows in those programs. Methods A questionnaire was delivered to all Accreditation Council for Graduate Medical Education-accredited pain medicine fellowships to assess their demographic data in 2018. Program characteristics are summarized using median (25th, 75th) for continuous variables and frequency counts and percentages for categorical variables. Analyses were then performed using a generalized linear mixed model with a logit link function and fellowship program included as a random effect. The gender of the fellow was the dependent variable and the program characteristics were the explanatory variables. Results Data from 45 of 104 fellowship programs (43% response rate) are included. From univariate analysis, the odds of a fellow being female were higher in programs with a female program director (OR=2.17, 95% CI 1.29 to 3.65, p=0.004) and in programs with a higher percentage of female faculty (OR=1.02, 95% CI 1.00 to 1.04, p=0.027). From multivariable analysis, having a female program director was the only program characteristic found to be significantly associated with female fellows (OR=2.07, 95% CI 1.05 to 4.11, p=0.037). Conclusions Pain medicine fellowship programs with a female program director were significantly more likely to have female fellows.

Introduction. Some patients with head and neck cancers have pain refractory to aggressive multimodal therapies. Herein, we report the use of an intrathecal targeted drug delivery (TDD) system catheter tip placed at C1 for the treatment of recalcitrant oropharyngeal cancer pain. Case Report. A patient with recurrent metastatic squamous cell tongue cancer reported severe pain not controlled despite high-dose opioids and nonopioid adjuvants. It was elected to proceed with an intrathecal TDD system with the catheter tip placed at the C1 level. After pump placement, we were able to decrease her daily oral morphine equivalents (OME) from nearly 1000 mg to 300 mg over the course of two months while titrating her TDD from 0.3 mg/day to 0.7 mg/day of intrathecal hydromorphone. Unfortunately, her improvement was limited secondary to aggressive cancer-directed treatments likely contributing to device infection and explant. Conclusions. In this patient, high cervical placement of an intrathecal TDD catheter was associated with a decrease in OME. While used in clinical practice on occasion, the use of high cervical TDD placement such as this implantable C1 intrathecal TDD system for cancer-associated pain is underreported in the literature. Further studies on this intervention within this challenging population are warranted.

Pain is one of the most commonly experienced and feared symptoms faced by patients with a serious illness. For these patients, intrathecal drug delivery systems (IDDSs) provide greater potency and/or few systemic side effects. However, despite these benefits, the integration and management of IDDS for patients receiving hospice care has not been previous studied. An electronic, 18-question survey was sent to 200 hospice practitioners (physicians, nurse practitioners and nurses) in the state of Minnesota to explore their experience, confidence, and the perceived barriers to caring for patients with IDDS while being cared for on hospice. Providers were identified though mailing lists from the Minnesota Network of Hospice and Palliative Care organization. The survey was administered by the Mayo Clinic Survey Research Center with institutional review board approval. Slightly more than 50% of respondents have ever cared for a patient with an intrathecal pump. If a patient had a pump in place, only 28% of providers expressed confidence in managing their pain. Additionally, only 3 of 10 respondents felt that adjusting an intrathecal pump should be the first option when a patient with an IDDS in place had increased pain. Indeed, the vast majority (over 80%) of respondents preferred the use of systemic therapies for primary pain management. Access to IDDS vendors for changes/refills in the home is identified as another barrier with over 50% of respondents either unaware of an available vendor or reporting no vendor available. There are numerous self-reported barriers to ongoing use of IDDS with patients receiving hospice care.