Blood Pressure and Outcome After Mechanical Thrombectomy With Successful Revascularization.

Background and Purpose- Successful reperfusion can be achieved in more than two-thirds of patients treated with mechanical thrombectomy. Therefore, it is important to understand the effect of blood pressure (BP) on clinical outcomes after successful reperfusion. In this study, we investigated the relationship between BP on admission and during the first 24 hours after successful reperfusion with clinical outcomes. Methods- This was a multicenter study from 10 comprehensive stroke centers. To ensure homogeneity of the studied cohort, we included only patients with anterior circulation who achieved successful recanalization at the end of procedure. Clinical outcomes included 90-day modified Rankin Scale, symptomatic intracerebral hemorrhage (sICH), mortality, and hemicraniectomy. Results- A total of 1245 patients were included in the study. Mean age was 69±14 years, and 51% of patients were female. Forty-nine percent of patients had good functional outcome at 90-days, and 4.7% suffered sICH. Admission systolic BP (SBP), mean SBP, maximum SBP, SBP SD, and SBP range were associated with higher risk of sICH. In addition, patients in the higher mean SBP groups had higher rates of sICH. Similar results were found for hemicraniectomy. With respect to functional outcome, mean SBP, maximum SBP, and SBP range were inversely associated with the good outcome (modified Rankin Scale score, 0-2). However, the difference in SBP parameters between the poor and good outcome groups was modest. Conclusions- Higher BP within the first 24 hours after successful mechanical thrombectomy was associated with a higher likelihood of sICH, mortality, and requiring hemicraniectomy.

Rate of Symptomatic Intracerebral Hemorrhage Related to Intravenous tPA Administered Over Telestroke Within 4.5-Hour Window.

BACKGROUND: Intravenous tissue plasminogen activator (tPA) remains the cornerstone medical treatment for acute ischemic stroke. The establishment of telestroke technology has allowed patients presenting to hospitals that lack expert stroke care to be evaluated and receive tPA. The safety of tPA administered through telestroke has been evaluated only when tPA is given within the 3-h window of last known normal. The purpose of this study is to evaluate the safety of tPA when administered through telestroke within a 4.5-h window. METHODS: A retrospective analysis on the prospectively collected database for all patients who received tPA at the Medical University of South Carolina Comprehensive Stroke Center (MUSC) (hub), as well as the MUSC telestroke network partner hospitals (spokes), was performed. Collected data included demographics, baseline characteristics, time from last known well to tPA administration, and symptomatic intracerebral hemorrhage (sICH) rates. Logistic regression was used to examine the odds of a sICH in patients at spoke sites compared with the hub controlling for patient stroke severity, gender, age, and race. RESULTS: A total of 830 patients were identified. Median National Institute of Health Stroke Scale was significantly higher among patients treated at the hub (9 vs. 8, p = 0.013), and the hub treated a higher percentage of nonwhite patients (p = 0.039). sICH occurred in 27 (4.8%) in the spoke group and 10 (3.8%) in the hub group (p = 0.523). Logistic regression results found no significant difference in the odds of sICH if tPA is given in a spoke site. CONCLUSIONS: Our study shows similar rates of sICH when intravenous tPA is administered at spokes through telestroke network compared with the hub.

Investigating the Interplay Between Matrix Compliance and Passaging History on Chondrogenic Differentiation of Mesenchymal Stem Cells Encapsulated Within Alginate-Gelatin Hybrid Hydrogels.

Mesenchymal stem cells (MSCs) are used widely in tissue engineering and regenerative medicine because of their ease of isolation and their pluripotency. The low survival and retention rate of MSCs at the target site upon implantation can be addressed via encapsulation within hydrogels capable of directing their fate. In this study, the interplay between matrix mechanics and the passage number of MSCs on their chondrogenic differentiation was assessed. Human bone marrow-derived MSCs between passages 4 and 6 were encapsulated within alginate-gelatin hybrid gels. The stiffness of the gels was varied by varying alginate concentrations while maintaining the concentration of gelatin and consequently, the cell adhesion sites, constant. The study revealed that within 4.8 kPa gels, GAG deposition was higher by P4 MSCs compared to P6 MSCs. However, an opposite trend was observed with collagen type 2 deposition. Further, we observed enhanced chondrogenic differentiation upon encapsulation of MSCs within 6.7 kPa hydrogel irrespective of passaging history. However, the effect of matrix compliance was more prominent in the case of higher passaged MSCs suggesting that matrix stiffness can help rescue the reduced differentiation capability of these cells.

Emerging Advances in Microfluidic Hydrogel Droplets for Tissue Engineering and STEM Cell Mechanobiology.

Hydrogel droplets are biodegradable and biocompatible materials with promising applications in tissue engineering, cell encapsulation, and clinical treatments. They represent a well-controlled microstructure to bridge the spatial divide between two-dimensional cell cultures and three-dimensional tissues, toward the recreation of entire organs. The applications of hydrogel droplets in regenerative medicine require a thorough understanding of microfluidic techniques, the biocompatibility of hydrogel materials, and droplet production and manipulation mechanisms. Although hydrogel droplets were well studied, several emerging advances promise to extend current applications to tissue engineering and beyond. Hydrogel droplets can be designed with high surface-to-volume ratios and a variety of matrix microstructures. Microfluidics provides precise control of the flow patterns required for droplet generation, leading to tight distributions of particle size, shape, matrix, and mechanical properties in the resultant microparticles. This review focuses on recent advances in microfluidic hydrogel droplet generation. First, the theoretical principles of microfluidics, materials used in fabrication, and new 3D fabrication techniques were discussed. Then, the hydrogels used in droplet generation and their cell and tissue engineering applications were reviewed. Finally, droplet generation mechanisms were addressed, such as droplet production, droplet manipulation, and surfactants used to prevent coalescence. Lastly, we propose that microfluidic hydrogel droplets can enable novel shear-related tissue engineering and regeneration studies.

Monolithically 3D-Printed Microfluidics with Embedded µTesla Pump.

Microfluidics has earned a reputation for providing numerous transformative but disconnected devices and techniques. Active research seeks to address this challenge by integrating microfluidic components, including embedded miniature pumps. However, a significant portion of existing microfluidic integration relies on the time-consuming manual fabrication that introduces device variations. We put forward a framework for solving this disconnect by combining new pumping mechanics and 3D printing to demonstrate several novel, integrated and wirelessly driven microfluidics. First, we characterized the simplicity and performance of printed microfluidics with a minimum feature size of 100 µm. Next, we integrated a microtesla (µTesla) pump to provide non-pulsatile flow with reduced shear stress on beta cells cultured on-chip. Lastly, the integration of radio frequency (RF) device and a hobby-grade brushless motor completed a self-enclosed platform that can be remotely controlled without wires. Our study shows how new physics and 3D printing approaches not only provide better integration but also enable novel cell-based studies to advance microfluidic research.

Facial Baroparesis Mimicking Stroke.

We report a case of a 55-year-old male who experienced unilateral facial muscle paralysis upon ascent to altitude on a commercial airline flight, with resolution of symptoms shortly after descent. The etiology was determined to be facial nerve barotrauma, or facial baroparesis, which is a known but rarely reported complication of scuba diving, with even fewer cases reported related to aviation. The history and proposed pathogenesis of this unique disease process are described.