Development and Evaluation of a Virtual Reality Simulator for Spinal Cord Stimulation: A Randomized Controlled Trial.

Purpose: The aim of this prospective study was to develop a virtual reality simulator (VRS) for spinal cord stimulation (SCS) trials and establish its effectiveness. Methods: We developed a VRS for SCS training by integrating patient imaging data analytics, creating artificial X-ray images, and using spatial alignment techniques and virtual reality technologies. The simulator was created by a physician with considerable experience in performing SCS, and can simulate the feeling of the procedure in a virtual environment. The efficacy of the simulator for SCS trials was assessed using a cohort of 20 novice trainees. The primary outcomes were duration of the procedure, checklist score, number of C-arm images captured, and overall trainee satisfaction. Results: The cohort that utilized the VRS had better Zwisch scale scores (P <0.001), completed the procedure in a shorter time (P <0.001), took fewer C-arm images (P <0.001), and reported better overall satisfaction (P = 0.011) than the cohort that did not. Conclusion: We developed a realistic and efficient VRS for educating novice trainees on SCS trials, thereby eliminating the risk of radiation exposure associated with cadaver training. The results of this study indicate that our VRS has potential as an instrumental resource that can be integrated into the educational framework for SCS trials.

Iliopsoas plane block does not improve pain after primary total hip arthroplasty in the presence of multimodal analgesia: a single institution randomized controlled trial.

BACKGROUND: The clinical analgesic efficacy of iliopsoas plane block remains a subject of discussion. This study aimed to assess the analgesic efficacy of iliopsoas plane block under general anesthesia using multimodal analgesia. METHODS: Fifty-six adult patients who underwent elective primary hip arthroplasty were enrolled. Patients were randomized to receive either a single-shot iliopsoas plane block (10 mL 0.75% ropivacaine with 1:200 000 epinephrine) or a sham block (10 mL normal saline). All patients received general anesthesia, multimodal analgesia (preoperative buprenorphine patch, 5 µg/h), intraoperative intravenous dexamethasone (8 mg) and nefopam (20 mg), and round-the-clock acetaminophen and celecoxib. The primary outcome was the numeric rating scale pain score at rest 6 hour after surgery. RESULTS: Iliopsoas plane block did not have a notable advantage over the sham block in terms of pain relief at rest, as assessed by the numeric rating scale score, 6 hour after total hip arthroplasty (iliopsoas plane block: median, 4.0; IQR, 2.0-5.8; sham: median, 5.5; IQR, 2.3-6.8; median difference, -1.0; 95% CI -2.0 to 0.0; p≥0.999). Linear mixed model analysis showed no differences in pain scores, opioid consumption, quadriceps strength, or quality of recovery between the groups. CONCLUSIONS: Iliopsoas plane block did not improve postoperative analgesia following total hip arthroplasty under general anesthesia with a multimodal analgesic regimen. The blockade of sensory femoral branches supplying the anterior hip capsule using iliopsoas plane block may not yield additional benefits concerning patient outcomes in the aforementioned clinical context. TRIAL REGISTRATION NUMBER: NCT05212038, https://clinicaltrials.gov/ct2/show/NCT05212038.

Ability of dynamic preload indices to predict fluid responsiveness in a high femoral-to-radial arterial pressure gradient: a retrospective study.

BACKGROUND: Dynamic preload indices may predict fluid responsiveness in end-stage liver disease. However, their usefulness in patients with altered vascular compliance is uncertain. This study is the first to evaluate whether dynamic indices can reliably predict fluid responsiveness in patients undergoing liver transplantation with a high femoral-to-radial arterial pressure gradient (PG). METHODS: Eighty liver transplant recipients were retrospectively categorized as having a normal (n = 56) or high (n = 24, difference in systolic pressure ≥ 10 mmHg and/or mean pressure ≥ 5 mmHg) femoral-to-radial arterial PG, measured immediately after radial and femoral arterial cannulation. The ability of dynamic preload indices (stroke volume variation, pulse pressure variation [PPV], pleth variability index) to predict fluid responsiveness was assessed before the surgery. Fluid replacement of 500 ml of crystalloid solution was performed over 15 min. Fluid responsiveness was defined as ≥ 15% increase in the stroke volume index. The area under the receiver-operating characteristic curve (AUC) indicated the prediction of fluid responsiveness. RESULTS: Fourteen patients in the normal, and eight in the high PG group were fluid responders. The AUCs for PPV in the normal, high PG groups and total patients were 0.702 (95% confidence interval [CI] 0.553-0.851, P = 0.008), 0.633 (95% CI 0.384-0.881, P = 0.295) and 0.667 (95% CI 0.537-0.798, P = 0.012), respectively. No other index predicted fluid responsiveness. CONCLUSIONS: PPV can be used as a dynamic index of fluid responsiveness in patients with end-stage liver disease but not in patients with altered vascular compliance.

Nonspherical Polyvinyl Alcohol Particles versus Tris-Acryl Microspheres: Randomized Controlled Trial Comparing Pain after Uterine Artery Embolization for Symptomatic Fibroids.

Background Data are limited regarding comparison between nonspherical polyvinyl alcohol (PVA) particles and tris-acryl gelatin microspheres (TAGM) in uterine artery embolization (UAE). Purpose To compare pain after UAE with PVA versus TAGM for treatment of symptomatic fibroids. Materials and Methods In this randomized clinical trial, participants were assigned to be administered nonspherical PVA (355-550 µm) or TAGM (500-700 µm). Both groups were administered fentanyl-based intravenous patient-controlled analgesia during the first 24 hours after UAE and rescue analgesics. Neutrophil-to-lymphocyte ratio was measured to assess inflammatory response. Contrast-enhanced MRI 1 day after UAE was used to evaluate dominant fibroid necrosis and ischemia of normal myometrium. Symptom severity score and health-related quality-of-life score were assessed before and 3 months after UAE. Variables measured over time were analyzed by using the generalized estimating equation method. Results A total of 54 participants (mean age, 44 years ± 4 [standard deviation]) were evaluated (27 participants in each group). Although pain scores and fentanyl dose were not different during the first 24 hours, use of rescue analgesics was higher in the PVA group (33% vs 11%; P = .049). After embolization, symptom severity score and health-related quality-of-life score were not different between groups (symptom severity score: 16 [interquartile range, 6-22] for PVA vs 19 [interquartile range, 9-34] for TAGM, P = .45; health-related quality-of-life score: 93 [interquartile range, 80-97] for PVA vs 89 [interquartile range, 84-96] for TAGM, P = .41). Changes in neutrophil-to-lymphocyte ratio from before to 24 hours after UAE were greater in the PVA group (3.9 [interquartile range, 2.7-6.8] for PVA and 2.5 [interquartile range, 1.5-4.6] for TAGM; P = .02). Rates of complete dominant fibroid necrosis were not different between groups, but transient global uterine ischemia of normal myometrium was more frequent in the PVA group (44% vs 15%; P = .04). Conclusion When used in uterine artery embolization, polyvinyl alcohol particles and tris-acryl gelatin microspheres resulted in similar pain scores and fentanyl dose. Polyvinyl alcohol resulted in a greater inflammatory response, higher rates of rescue analgesic use, and more frequent transient global uterine ischemia. © RSNA, 2020 See also the editorial by Spies and Frenk in this issue.

Tubby domain superfamily protein is required for the formation of the 7S SNARE complex in Drosophila.

Tubby domain superfamily protein (TUSP) is a distant member of the Tubby-like protein (TULP) family. Although other TULPs play important roles in sensation, metabolism, and development, the molecular functions of TUSP are completely unknown. Here, we explore the function of TUSP in the Drosophila nervous system where it is expressed in all neurons. Tusp mutant flies exhibit a temperature-sensitive paralysis. This paralysis can be rescued by tissue-specific expression of Tusp in the giant fibers and peripherally synapsing interneurons of the giant fiber system, a well-characterized neuronal circuit that mediates rapid escape behavior in flies. Consistent with this paralytic phenotype, we observed a profound reduction in the assembly of the ternary 7S SNARE complex that is required for neurotransmitter release despite seeing no changes in the expression of each individual SNARE complex component. Together, these data suggest TUSP is a novel regulator of SNARE assembly and, therefore, of neurotransmitter release.

Hypothermia inhibits the propagation of acute ischemic injury by inhibiting HMGB1.

Acute ischemic stroke causes significant chronic disability worldwide. We designed this study to clarify the mechanism by which hypothermia helps alleviate acute ischemic stroke. In a middle cerebral artery occlusion model (4 h ischemia without reperfusion), hypothermia effectively reduces mean infarct volume. Hypothermia also prevents neurons in the infarct area from releasing high mobility group box 1 (HMGB1), the most well-studied damage-associated molecular pattern protein. By preventing its release, hypothermia also prevents the typical middle cerebral artery occlusion-induced increase in serum HMGB1. We also found that both glycyrrhizin-mediated inhibition of HMGB1 and intracerebroventricular neutralizing antibody treatments before middle cerebral artery occlusion onset diminish infarct volume. This suggests a clear neuroprotective effect of HMGB1 inhibition by hypothermia in the brain. We next used real-time polymerase chain reaction to measure the levels of pro-inflammatory cytokines in peri-infarct regions. Although middle cerebral artery occlusion increases the expression of interleukin-1ß and tissue necrosis factor-α, this elevation is suppressed by both hypothermia and glycyrrhizin treatment. We show that hypothermia reduces the production of inflammatory cytokines and helps salvage peri-infarct regions from the propagation of ischemic injury via HMGB1 blockade. In addition to suggesting a potential mechanism for hypothermia's therapeutic effects, our results suggest HMGB1 modulation may lengthen the therapeutic window for stroke treatments.