Nationwide Incidence and Trends in Central Retinal Arterial Occlusion Management: A 5000-Patient Analysis.

Central retinal artery occlusion (CRAO) is a rare and visually debilitating vascular condition characterized by sudden and severe vision loss. CRAO is a compelling target for intravenous alteplase (tPA) and endovascular mechanical thrombectomy (MT) due to pathophysiological similarities with acute ischemic stroke; however, the utility of these interventions in CRAO remains dubious due to limited sample sizes and potential risks. To assess usage and outcomes of tPA and MT in CRAO, we queried the National Inpatient Sample database using International Classification of Disease, Ninth and Tenth edition for patients with CRAO and acute ischemic stroke between 2010 and 2019. Our cohort of 5009 CRAO patients were younger with higher rates of obesity, hypertension, long-term anticoagulant use, and tobacco use compared to acute ischemic stroke patients. CRAO patients had lower rates of tPA administration (3.41% vs 6.21%) and endovascular MT (0.38% vs 1.31%) but fewer complications, including deep vein thrombosis, pneumonia, urinary tract infection, acute kidney injury, and acute myocardial infarction (all P < 0.01). CRAO patients had lower rates of poor functional outcome (31.74% vs 58.1%) and in-hospital mortality (1.2% vs 5.64%), but higher rates of profound blindness (9.24% vs 0.58%). A multivariate regression showed no relationship between tPA and MT and profound blindness, although the limited sample size of patients receiving interventions may have contributed to this apparent insignificance. Further investigation of larger patient cohorts and alternative treatment modalities could provide valuable insights for revascularization therapies in CRAO to optimize visual restoration and clinical outcomes.

Frailty as a Predictor of Outcomes in Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis.

Frailty is an emerging concept in clinical practice used to predict outcomes and dictate treatment algorithms. Frail patients, especially older adults, are at higher risk for adverse outcomes. Aneurysmal subarachnoid hemorrhage (aSAH) is a neurosurgical emergency associated with high morbidity and mortality rates that have previously been shown to correlate with frailty. However, the relationship between treatment selection and post-treatment outcomes in frail aSAH patients is not established. We conducted a meta-analysis of the relevant literature in accordance with PRISMA guidelines. We searched PubMed, Embase, Web of Science, and Google Scholar using "Subarachnoid hemorrhage AND frailty" and "subarachnoid hemorrhage AND frail" as search terms. Data on cohort age, frailty measurements, clinical grading systems, and post-treatment outcomes were extracted. Of 74 studies identified, four studies were included, with a total of 64,668 patients. Percent frailty was 30.4% under a random-effects model in all aSAH patients (p < 0.001). Overall mortality rate of aSAH patients was 11.7% when using a random-effects model (p < 0.001). There was no significant difference in mortality rate between frail and non-frail aSAH patients, but this analysis only included two studies and should be interpreted cautiously. Age and clinical grading, rather than frailty, independently predicted outcomes and mortality in aSAH patients.

Hyperinsulinemia induces early and dyssynchronous puberty in lean female mice.

Girls with obesity are at increased risk of early puberty. Obesity is associated with insulin resistance and hyperinsulinemia. We hypothesized that insulin plays a physiological role in pubertal transition, and super-imposed hyperinsulinemia due to childhood obesity promotes early initiation of puberty in girls. To isolate the effect of hyperinsulinemia from adiposity, we compared pre-pubertal and pubertal states in hyperinsulinemic, lean muscle (M)-insulin-like growth factor 1 receptor (IGF-1R)-lysine (K)-arginine (R) (MKR) mice to normoinsulinemic WT, with puberty onset defined by vaginal opening (VO). Our results show MKR had greater insulin resistance and higher insulin levels (P < 0.05) than WT despite lower body weight (P < 0.0001) and similar IGF-1 levels (P = NS). Serum luteinizing hormone (LH) levels were higher in hyperinsulinemic MKR (P = 0.005), and insulin stimulation induced an increase in LH levels in WT. VO was earlier in hyperinsulinemic MKR vs WT (P < 0.0001). When compared on the day of VO, kisspeptin expression was higher in hyperinsulinemic MKR vs WT (P < 0.05), and gonadotropin-releasing hormone and insulin receptor isoform expression was similar (P = NS). Despite accelerated VO, MKR had delayed, disordered ovarian follicle and mammary gland development. In conclusion, we found that hyperinsulinemia alone without adiposity triggers earlier puberty. In our study, hyperinsulinemia also promoted dyssynchrony between pubertal initiation and progression, urging future studies in girls with obesity to assess alterations in transition to adulthood.

Improved Functional Assessment of Ischemic Severity Using 3D Printed Models.

Objective: To develop a novel in vitro method for evaluating coronary artery ischemia using a combination of non-invasive coronary CT angiograms (CCTA) and 3D printing (FFR3D). Methods: Twenty eight patients with varying degrees of coronary artery disease who underwent non-invasive CCTA scans and invasive fractional flow reserve (FFR) of their epicardial coronary arteries were included in this study. Coronary arteries were segmented and reconstructed from CCTA scans using Mimics (Materialize). The segmented models were then 3D printed using a Carbon M1 3D printer with urethane methacrylate (UMA) family of rigid resins. Physiological coronary circulation was modeled in vitro as flow-dependent stenosis resistance in series with variable downstream resistance. A range of physiological flow rates (Q) were applied using a peristaltic steady flow pump and titrated with a flow sensor. The pressure drop (ΔP) and the pressure ratio (Pd/Pa) were assessed for patient-specific aortic pressure (Pa) and differing flow rates (Q) to evaluate FFR3D using the 3D printed model. Results: There was a good positive correlation (r = 0.87, p < 0.0001) between FFR3D and invasive FFR. Bland-Altman analysis revealed a good concordance between the FFR3D and invasive FFR values with a mean bias of 0.02 (limits of agreement: -0.14 to 0.18; p = 0.2). Conclusions: 3D printed patient-specific models can be used in a non-invasive in vitro environment to quantify coronary artery ischemia with good correlation and concordance to that of invasive FFR.

Stereolithography for Personalized Left Atrial Appendage Occluders.

Advancements in 3D additive manufacturing have spurred the development of effective patient-specific medical devices. Prior applications are limited to hard materials, however, with few implementations of soft devices that better match the properties of natural tissue. This paper introduces a rapid, low cost, and scalable process for fabricating soft, personalized medical implants via stereolithography of elastomeric polyurethane resin. The effectiveness of this approach is demonstrated by designing and manufacturing patient-specific endocardial implants. These devices occlude the left atrial appendage, a complex structure within the heart prone to blood clot formation in patients with atrial fibrillation. Existing occluders permit residual blood flow and can damage neighboring tissues. Here, the robust mechanical properties of the hollow, printed geometries are characterized and stable device anchoring through in vitro benchtop testing is confirmed. The soft, patient-specific devices outperform non-patient-specific devices in embolism and occlusion experiments, as well as in computational fluid dynamics simulations.