Impact of temperature on the magnitude and duration of relief after lumbar facets medial branch nerves radiofrequency ablation: a randomized double-blinded study.

INTRODUCTION: There are numerous studies appraising the variables that may influence the clinical outcomes after lumbar thermal radiofrequency ablation (RFA). Expanding the lesion size may increase the likelihood of capturing the target nerves in the lesion, thereby increasing the technical success rate of RFA. However, our literature search has failed to identify a consensus on the optimal target temperature. A retrospective study demonstrated that there seems to be significant functional improvement associated with the temperature of 90°C compared with 80°C. The authors prospectively studied the subject in a double-blinded randomized fashion. METHODS: Patients undergoing RFA for lumbar facetogenic pain were randomized in two cohorts (80°C and 90°C). Physicians and patients were blinded to the temperature used. The primary outcome was self-reported pain scores up to 12 months. Secondary outcomes included: self-reported functional improvement, duration of relief as measured by the time before repeat ablation of the same medial branches nerves, opioids' consumption, and patient satisfaction. RESULTS: Both groups reported pain improvement in all follow-up time points. Overall, both groups achieved statistically significant pain reduction (p<0.05). The median time to repeat RFA in the 80°C group was 112 (49-252) days, while it was 217 (198-348) days in the 90°C group (p<0.04). The univariate analysis emphasized that the RFA temperature is a statistically significant factor for pain improvement of more than 50%, OR 2.7 (1.1 to 6.6) p value=0.031. CONCLUSION: RFA has been demonstrated as an effective therapeutic modality for lumbar facetogenic back pain. Yet, the several factors involved in determining a favorable outcome of this procedure require further research and optimization. This prospective double-blinded randomized trial demonstrated that RFA at both temperatures (80°C, 90°C) provided significance at all the time periods examined. However, RFA at 90°C was superior to 80°C in regard to the duration of relief.

Patient and physician radiation exposure during minimally invasive lumbar decompression: A prospective assessment of X-ray exposure risks.

INTRODUCTION: Minimally invasive lumbar decompression (mild®) is becoming a popular procedure for treating lumbar spinal stenosis (LSS) secondary to hypertrophic ligamentum flavum (LF). The mild® procedure is commonly performed under live fluoroscopic guidance and carries a risk of radiation exposure to the patient and healthcare. METHODS: One physician performed mild® on 41 patients at the Cleveland Clinic Department of Pain Management from October 2019 to December 2021, while wearing a radiation exposure monitor (Mirion Technologies). Mean fluoroscopy time, mean exposure per case, and mean exposure per unilateral level decompressed were the primary outcomes measured. The secondary outcome was to provide a comparison of radiation exposure during similar fluoroscopically guided procedures. RESULTS: Mean patient fluoroscopy exposure time was 2.1 min ±0.9 (range: 1.1-5.6) fluoroscopy time per unilateral level decompressed. The mean patient radiation skin exposure from mild® was 1.1 ± 0.9 mGym2, and the mean total dose was 142.3 ± 108.6 mGy per procedure. On average, the physician was exposed to an average deep tissue exposure of 4.1 ± 3.2 mRem, 2.9 ± 2.2 mRem estimated eye exposure, and 14.7 ± 11.0 mRem shallow tissue exposure per unilateral level decompressed. An individual physician would exceed the annual exposure limit of 5 Rem after approximately 610 mild® procedures per year. CONCLUSIONS: This study is an attempt to quantify the radiation exposure to the physician and patient during the mild® procedure. Compared with other fluoroscopically guided pain management procedures, patient and physician radiation exposure during mild® was low.

Pain Management Interventions for the Treatment of Chronic Low Back Pain: A Systematic Review and Meta-Analysis.

OBJECTIVE: Determine the relative effectiveness and safety profiles of percutaneous and minimally invasive interventions for chronic low back pain. METHODS: A systematic search was performed for randomized controlled trials published in the past 20 years reporting on radiofrequency ablation of the basivertebral, disk annulus and facet nerve structures, steroid injection of the disk, facet joint, and medial branch, biological therapies, and multifidus muscle stimulation. Outcomes evaluated included Visual Analog Scale (VAS) pain scores, Oswestry Disability Index (ODI) scores, quality of life (SF-36 and EQ-5D) scores, and serious adverse event (SAE) rates. Basivertebral nerve (BVN) ablation was chosen as the subject of comparison to all other therapies using a random-effects meta-analysis. RESULTS: Twenty-seven studies were included. BVN ablation was found to provide statistically significant improvements in VAS and ODI scores for 6-, 12- and 24-month follow-up ( P ≤0.05). Biological therapy and multifidus muscle stimulation were the only 2 treatments with both VAS and ODI outcomes not significantly different from BVN ablation at 6-, 12-, and 24-month follow-up. All outcomes found to be statistically significant represented inferior results to those of BVN ablation. Insufficient data precluded meaningful comparisons of SF-36 and EQ-5D scores. The SAE rates for all therapies and all reported time points were not significantly different from BVN ablation except for biological therapy and multifidus muscle stimulation at the 6-month follow-up. CONCLUSIONS: BVN ablation, biological therapy, and multifidus stimulation all provide significant, durable improvements in both pain and disability compared with other interventions, which provided only short-term pain relief. Studies on BVN ablation reported no SAEs, a significantly better result than for studies of biological therapy and multifidus stimulation.

The Choice of Spinal Cord Stimulation Versus Targeted Drug Delivery in the Management of Chronic Pain: Validation of an Outcomes Predictive Formula.

OBJECTIVE: In 2020, Mekhail et al published a formula that predicted the likelihood of a successful outcome for those who undergo spinal cord stimulation (SCS) for long-term pain management, based on retrospectively collected clinical and demographic data from one major medical center. The aim of this study is to validate such a predictive formula, prospectively, in a cohort of patients from multiple medical practices that are more representative of real-life clinical practice. MATERIALS AND METHODS: For the study, 939 patients who underwent successful SCS or targeted drug delivery (TDD) trials at multiple independent medical centers in the USA were enrolled into the Medtronic product surveillance registry data base before they underwent SCS or TDD device implantation, from 2018 to 2020. The registry data were collected prospectively but not specifically for this study. The data examined included demographic information, pain diagnosis, pain scores (visual analog scale [VAS]), Oswestry Disability Index scores, and quality-of-life scores at baseline and six months after implant. Because our goal is to validate the previously published predictive formula, in addition to the outcomes data previously mentioned, we collected the variables necessary for such a task: sex, age, depression, the presence of neuropathic pain, spine-related pain diagnosis, and persistent spinal pain syndrome "post laminectomy syndrome." Spine-related pain diagnosis included subjects with chronic spine pain who never had back surgery and whose pain was not radicular nor neuropathic. RESULTS: Of 619 patients with SCS, 138 (22%) achieved ≥ 50% reductions of the baseline VAS at six months. The logistic model predicts SCS success with an area under the receiver operating characteristic curve (AUC) of 80% in the current validation data set. Of 320 patients with TDD, 147 (46%) achieved ≥ 50% reduction of the baseline VAS at six months. The logistic model predicts TDD success with an AUC of 78% in the current validation data set. CONCLUSION: The study provides real life validation of the previously published predictive formula(4).

Granular cell tumor presenting with perforation of fourth part of the duodenum: A case report.

INTRODUCTION: Granular cell tumors (GCT) are relatively rare neoplasms most commonly occurring in skin or soft tissues. GCT are thought to be of Schwann cell origin and strongly positive for s100 protein. GCT of the intestinal tract are usually asymptomatic and found incidentally in the esophagus on endoscopy. CASE PRESENTATION: Here, we present a case of GCT jejunum and the fourth part of the duodenum. The patient is a 41-year-old female who presented with abdominal pain and was subsequently found to have pneumoperitoneum with a perforation of the fourth part of the duodenum. Intraoperatively, there were multiple enlarged and hard mesenteric lymph nodes, which were found to be due to GCT involving the fourth duodenum and proximal jejunum. CLINICAL DISCUSSION: The occurrence of GCT in the gastrointestinal (GI) tract are even less common accounting for 5-9% of all GCT with very few cases reported in the duodenum. GCT of the GI tract are often asymptomatic, consequently leading to misdiagnosed delays in treatment. CONCLUSION: In the setting of GCT in the fourth part of the duodenum with evidence of locally advanced disease, local resection is the preferred treatment.

Perianal squamous cell carcinoma: A case report.

INTRODUCTION AND IMPORTANCE: Perianal carcinomas, though rare, are usually squamous cell carcinoma. Current literature recommends surgical excision for tumors staged T1-T2, N0 without external anal sphincter involvement, however our case demonstrated that tumors with superficial involvement of external sphincter fibers can be resected completely. CASE PRESENTATION: A 45-year-old Caucasian male presented with a perianal mass found to be squamous cell carcinoma. Initial imaging suggested the anal sphincter was spared, however intraoperatively tumor cells were found involving superficial external sphincter fibers and a portion was excised to ensure complete removal. CLINICAL DISCUSSION: Perianal squamous malignancies are often misdiagnosed as more benign conditions. Treatment aims to preserve sphincter function and depends on tumor stage along with anatomical involvement. CONCLUSION: Despite superficial muscle infiltration, the T2N0 perianal lesion was curable with surgical resection alone without recurrence or functional deficits reported one year later. This suggests surgical management may be possible in some cases with sphincter involvement.

Rapid prototyping of pneumatically actuated hydrocarbon gel valves for centrifugal microfluidic devices.

A novel, easy to prototype hydrocarbon gel-based active valve was developed for use in centrifugal microfluidic devices. The valve has been demonstrated to restrict flow by an additional 1000 revolutions per minute (RPM) when compared to a passive capillary valve of the same size located at the same radius. Opening of the valve is accomplished in a contactless manner using a stream of focused compressed air. The ease of fabrication, low cost and small dimensions of the gel valve offer the potential for integration of multiple valves of this type into multi-process centrifugal microfluidic systems.

Automated liquid-liquid extraction by pneumatic recirculation on a centrifugal microfluidic platform.

In this technical note, a liquid-liquid extraction technique was performed using pneumatic liquid recirculation on a centrifugal microfluidic device. Non-contact pneumatic pumping enabled a multi-cycle liquid-liquid extraction process using aqueous iodine in a potassium iodide solution and hexadecane while requiring a minimal amount of space on the device. The extraction process was completely automated on the device following sample introduction and required only 50 s for each extraction cycle. The pumping rate achieved during liquid recirculation was 120 ± 10 µL/min. A recycling process such as the one demonstrated would be difficult to implement in a conventional centrifugal microfluidic system.

Rapid simultaneous determination of nitrate and nitrite on a centrifugal microfluidic device.

A centrifugal microfluidic device was developed for the rapid sequential determination of two critical environmental species, nitrate and nitrite, in water samples. The nitrate is reduced to nitrite and the nitrite is derivatized. The analytes are determined spectrophotometrically through the disc with a 1.4mm pathlength. The detection limits are 0.05 and 0.16 mg L(-1) for nitrite and nitrate respectively. The use of powdered reagents, the 100 microL sample required and the design of the device suggest that it would be suitable for field use.

A rapid prototyping technique for valves and filters in centrifugal microfluidic devices.

Using short lengths of fused silica capillary tubing embedded in the disk, a system for valving and filtering samples on centrifugal microfluidic devices has been designed and implemented. Sedimentation of turbid samples and transfer of the clear supernatant was also accomplished. Also demonstrated is the transfer of the liquid through a second capillary valve to the final reservoir. By controlling rotational speed, sedimentation and multiple step valving operations are readily implemented and easily prototyped.

Discovery, biosynthesis, and structure elucidation of metabolites of a doping agent and a direct analogue, tetrahydrogestrinone and gestrinone, using human hepatocytes.

Tetrahydrogestrinone (18a-homo-pregna-4,9,11-trien-17beta-ol-3-one, THG) is an anabolic androgenic steroid sold to athletes as an undetectable performance enhancer. Being an unapproved substance, no legitimate in vivo human excretion studies could be performed to identify urinary markers of this doping agent. In vitro systems were used as an alternative approach to study the human metabolism of THG and the gestrinone analogue, which is a marketed drug. Incubations of both compounds in the presence of human hepatocytes led to formation of oxidative and glucuroconjugated metabolites. Microgram quantities of the major in vitro metabolites were biosynthesized using human hepatocytes, characterized by HPLC/MS/MS, and their structures elucidated by NMR. Due to high structure similarity, both THG and gestrinone had an analogous in vitro metabolic pathway leading to successive addition of a hydroxyl and a beta-glucuronic acid at C-18. This in vitro metabolite of gestrinone was consistent with a previously reported major but unknown human urinary metabolite. The structure of another metabolite of THG was proposed to be a glucuroconjugate of an oxidative product with a hydroxyl group most likely at C-16epsilon. In vitro information reported therein could significantly impact the identification of new urinary markers of THG for doping control purposes.