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Coronary artery disease (CAD) is characterized by narrowing and subsequent blockade of coronary arteries, and imposes a significant health and economic burden. Stent and scaffold devices are introduced in advanced CAD to improve vascular stability and restore blood flow. Although in vitro flow systems like the Chandler loop have been developed to enhance the understanding of interactions between device materials, their coatings, and vascular cells, imaging-based in vitro analysis of device performance is limited. In this study, we established a novel stent flow chamber system designed to assess the thrombogenicity of bioresorbable magnesium scaffold (RMS) and stent materials in vitro. Additionally, we compared the thrombogenicity – an important clinical parameter in stent performance – of the Magmaris-316 L stainless steel stent with its predecessors, Magmaris RMS and a prototype of the third-generation RMS (DREAMS 3G). Analysis of platelet adhesion and coverage of the different devices under flow conditions demonstrated that the Magmaris RMS exhibits reduced thrombogenicity compared to the Magmaris-316 L stainless steel stent. Moreover, thrombogenicity of the DREAMS 3G prototype, composed of BIOmag material, is further decreased compared to its predecessors. The observed reduction in thrombogenicity of the DREAMS 3G prototype in vitro suggests additional improvements in clinical safety and efficacy, highlighting its promise for treating CAD. Future research on this prototype may thus open avenues for analyzing other blood components and patient-derived endothelial cells. In line with the 3R principles, this approach may also help reduce the need for animal testing. [ABSTRACT FROM AUTHOR]

Atherosclerosis is one of the important diseases of the circulatory system because atherosclerotic plaques cause significant disruption of blood flow. Therefore, it is very important to properly understand these processes and skillfully simulate blood flow. In our work, we consider blood flow through an abdominal aorta with iliac arteries, assuming that the right iliac artery is narrowed by an atherosclerotic lesion. Blood flow is simulated using the laminar, standard k - ω and standard k - ϵ models. The obtained results show that despite the use of identical initial conditions, the distribution of velocity flow and wall shear stress depends on the choice of flow simulation model. For the k - ϵ model, we obtain higher values of speed and wall shear stress on atherosclerotic plaque than in the other two models. The laminar and k - ω models predict larger areas where reverse blood flow occurs in the area behind the atherosclerotic lesion. This effect is associated with negative wall shear stress. These two models give very similar results. The results obtained by us, and those reported in the literature, indicate that k - ω model is the most suitable for blood flow analysis. [ABSTRACT FROM AUTHOR]

Ischemic diseases are characterized by obstruction of blood flow to the respective organs, of which ischemia of the heart and brain are the most prominent manifestations with shared pathophysiological mechanisms and risk factors. While most revascularization therapies aim to restore blood flow, this can be challenging due to the limited therapeutic window available for treatment approaches. For a very long time, mesenchymal stromal cells have been used to treat cerebral and cardiac ischemia. However, their application is restricted either by inefficient mode of delivery or the low cell survival rates following implantation into the ischemic microenvironment. Nonetheless, several studies are currently focusing on using of mesenchymal stromal cells engineered to overexpress therapeutic genes as a cell-based gene therapy to restore angiogenesis. This review delves into the utilization of MSCs for angiogenesis and the applications of engineered MSCs for the treatment of cardiac and cerebral ischemia. Moreover, the safety issues related to the genetic modification of MSCs have also been discussed. [ABSTRACT FROM AUTHOR]

This is a summary of a consensus statement on the introduction of "Ultrasound microvasculomics" produced by The Chinese Artificial Intelligence Alliance for Thyroid and Breast Ultrasound. The evaluation of microvessels is a very important part for the assessment of diseases. Super-resolution ultrasound (SRUS) microvascular imaging surpasses traditional ultrasound imaging in the morphological and functional analysis of microcirculation. SRUS microvascular imaging relies on contrast microbubbles to gain sensitivity to microvessels and improves the spatial resolution of ultrasound blood flow imaging for a more detailed depiction of vascular structures and hemodynamics. This method has been applied in preclinical animal models and pilot clinical studies, involving areas including neurology, oncology, nephrology, and cardiology. However, the current quantitative parameters of SRUS images are not enough for precise evaluation of microvessels. Therefore, by employing omics methods, more quantification indicators can be obtained, enabling a more precise and personalized assessment of microvascular status. Ultrasound microvasculomics - a high-throughput extraction of image features from SRUS images - is one novel approach that holds great promise but needs further validation in both bench and clinical settings. Clinical relevance statement: Super-resolution Ultrasound (SRUS) blood flow imaging improves spatial resolution. Ultrasound microvasculomics is possible to acquire high-throughput information of features from SRUS images. It provides more precise and abundant micro-blood flow information in clinical medicine. Key Points: This consensus statement reviews the development and application of super-resolution ultrasound (SRUS). The shortcomings of the current quantification indicators of SRUS and strengths of the omics methodology are addressed. "Ultrasound microvasculomics" is introduced for a high-throughput extraction of image features from SRUS images. [ABSTRACT FROM AUTHOR]

Objectives: Detection of synovitis is essential for assessing the activity and predicting the prognosis of rheumatoid arthritis (RA). The aim of this study was to investigate the diagnostic performance of superb microvascular imaging (SMI) in RA patients with high, moderate, and low activity. Methods: One hundred four patients with active RA were selected from the hospital between May 2022 and August 2023. The study observed the correlation between bone erosion of the carpal joint, joint cavity effusion, thickness of synovial hyperplasia of the carpal joint, positivity rate of synovial blood vessels, and their semiquantitative scores with the clinical disease activity of RA using SMI examination. Results: The detection of synovial hyperplasia thickness and joint effusion in the high-activity group was higher than that in the low-activity group, and the difference was statistically significant (P < 0.05). The quantitative SMI test demonstrated that the synovial blood flow grading and semiquantitative grade increased gradually with activity level (P<0.05). During the high, moderate, and low-activity groups, the vascular index (VI) value of the hyperplastic synovial membrane decreased gradually, showing statistical significance both between and within the groups (P<0.05). Conclusion: SMI technology exhibited high sensitivity and accuracy in assessing disease activity in RA. It holds significant clinical application value as a reliable auxiliary tool for assessing disease activity in RA and treatment. Key Points • Super micro-vascular imaging (SMI) demonstrated higher detection rates of microvessels in RA patients with high disease activity compared to those with low activity, showing statistical significance. • The quantitative SMI test revealed a clear correlation between synovial blood flow grading and disease activity levels in RA patients, highlighting the potential of SMI as a valuable tool for disease activity and treatment of rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

Purpose: Fasciotomy is a surgical procedure that involves the incision of fascial compartments in the body to relieve pressure, prevent tissue damage, and maintain blood flow. This study aimed to investigate the effectiveness of the Bogota Bag technique in closing fasciotomy wounds in patients with lower limb compartment syndrome. Methods: A prospective cohort study was conducted between October 2022 and October 2023 to document our experience in employing the Bogota Bag technique for fasciotomy closure. The study included the evaluation of medical files from fifteen patients aged 17 to 61. Results: The outcomes of the study present the initial series of limb fasciotomies treated with the Bogota Bag technique. Fifteen patients (14 male, 1 female) were included in the study. The average age of the patients was 34.73 ± 13.9 years and the average hospitalization was 8.33 ± 3.2 days. The average closure time of fasciotomy is 3.6 ± 1.4 days. Conclusion: This report makes a significant contribution as the first documented series of limb fasciotomies treated with the Bogota Bag technique. This method exhibits simplicity in execution, cost-effectiveness, and a low incidence of complications. [ABSTRACT FROM AUTHOR]

In an era in which cardiovascular disease has become the main cause of death all over the world, diagnostic accuracy in identifying blood vessels has become particularly important. Vascular stenosis causes serious health risks by affecting blood flow, leading to conditions like heart attacks and strokes. Traditional diagnostic methods face challenges in terms of timeliness and accuracy. Our systematic review aims to critically assess the role of machine learning (ML) techniques in enhancing computed tomography angiography's (CTA) diagnostic capabilities for vasoconstriction. This review followed the predetermined inclusion and exclusion criteria and focused on research articles published between January 2013 and October 2023 collected from databases such as PubMed, IEEE, Web of Science, and Scopus. Studies focus on multiphase CTA or dynamic CTA; papers do not use the ML; and papers not in English are removed. The risk of bias of included studies was evaluated using the QUADAS2 tool. The results were analyzed in tabular form using metrics such as accuracy, sensitivity, and specificity and examine variations in stenosis detection by anatomical regions. In our review, a total of 63 studies were identified as relevant. These studies included a variety of ML applications for identifying anatomical stenosis of the arteries in different anatomical areas. The findings highlighted a trend of high sensitivity and specificity in broader anatomical assessments, with nuanced variations observed in detailed segmental analysis. The review acknowledges limitations within the existing studies, including the retrospective nature of most studies and their limited scope in terms of patient diversity and center variation. Nonetheless, the implications of integrating ML in vascular stenosis detection via CTA are profound, suggesting a pivotal shift toward more accurate, efficient, and patient-centric diagnostic practices in cardiovascular care. Registration: The protocol for this systematic review and meta-analysis was registered on PROSPERO, with the registration number CRD420234603. [ABSTRACT FROM AUTHOR]

Radiofrequency ablation is a promising technique for arrhythmia treatment in horses. Due to the thicker myocardial wall and higher blood flow in horses, it is unknown if conventional radiofrequency settings used in human medicine can be extrapolated to horses. The study aim is to describe the effect of ablation settings on lesion dimensions in equine myocardium. To study species dependent effects, results were compared to swine myocardium. Right ventricular and right and left atrial equine myocardium and right ventricular swine myocardium were suspended in a bath with circulating isotonic saline at 37 °C. The ablation catheter delivered radiofrequency energy at different-power-duration combinations with a contact force of 20 g. Lesion depth and width were measured and lesion volume was calculated. Higher power or longer duration of radiofrequency energy delivery increased lesion size significantly in the equine atrial myocardium and in equine and swine ventricular myocardium (P < 0.001). Mean lesion depth in equine atrial myocardium ranged from 2.9 to 5.5 mm with a diameter ranging from 6.9 to 10.1 mm. Lesion diameter was significantly larger in equine tissue compared to swine tissue (P = 0.020). Obtained data in combination with estimated wall thickness can improve lesion transmurality which might reduce arrhythmia recurrence. Optimal ablation settings may differ between species. [ABSTRACT FROM AUTHOR]

Background: Left ventricle (LV) volume overload is observed with hemodynamically significant PDA as it causes left to right shunting, leading to increased pulmonary blood flow. This overload causes LV remodeling as LV increases stroke volume in trial for compensation, but in larger shunts, patients may develop symptoms of congestive heart failure. Two-dimensional (2D) speckle-tracking echocardiography has emerged as a technique for objective and quantitative evaluation of global and regional myocardial function, independent of the angle of myocardial insonation. Aim of the work: This study aimed to evaluate left ventricular function by 2-dimensional speckle tracking in children with hemodynamically significant PDA. Methods: This prospective controlled study was performed on 54 children divided into two groups (34 as cases and 20 as controls) to compare echocardiographic measurements. Conventional Echocardiography, tissue Doppler, and Speckle tracking were done for all patients, and measurements were compared. Results: There was a statistically significant difference (p value < 0.001) in global longitudinal strain (GLS) in the PDA group indicating a decrease in LV function in PDA patients. This difference was observed in several conventional echocardiographic parameters but not in tissue Doppler in our study. Conclusion: Left ventricle global strain is an important predictor of the myocardial performance index of the Left ventricle in patients with hemodynamically significant PDA and outweighs other conventional echocardiographic parameters and tissue Doppler indices. [ABSTRACT FROM AUTHOR]

One risk of continuous renal replacement therapy (CRRT) is inadvertent hypothermia (IH), which is defined as a non-therapeutic core temperature decrease below normal. In continuous renal replacement therapy, heat loss will always occur from blood pumped through the dialysis circuit to cooler environment, predisposing for hypothermia. Blood flow and effluent flows are the most important parameters causing heat loss. We investigated and compared the novel TherMax warmer to previous generation technologies during CRRT in a multicenter setting. This was a prospective observational multicenter study with historic single-center controls. The study group consisted of 100 patients in eight Swedish ICUs with clinical indication for CRRT, using the PrisMax platform and TherMax warmer. Both patient and set warmer temperatures were recorded hourly for the first 24 h. The presence of treatment hours in hypothermia (< 36.0 Celsius) and the difference between set warmer temperature and measured patient temperature in the multi-center study cohort were compared to a matched single-center historic control cohort treated with the old Prismaflex platform and adjacent Barkey warmer. In the TherMax group 77/100 (77.0%) of patients, and for controls 26/86 (30.2%) of patients were free of hypothermia (Chi square, p < 0.001). The mean number of hours spent in hypothermia was (mean ± SD) 0.66 ± 1.60 and 6.92 ± 7.79 h in the TherMax and control groups, respectively (Chi square p < 0.001). In the study group the patient temperature was higher than the set temperature on the warmer with a difference of Δ0.47 ± 0.80 °C (minor difference), whereas in the control group the set temperature on the warmer was higher than the patient temperature with a difference of Δ4.55 ± 1.00 °C (over-correction). The novel TherMax warmer technology protected against hypothermia and was significantly more accurate than the Barkey warmer. [ABSTRACT FROM AUTHOR]

Epinephrine is the only recommended vasopressor during neonatal cardiopulmonary resuscitation. However, there are concerns about the potential adverse effects of epinephrine, which might hamper efficacy during cardiopulmonary resuscitation. An alternative might be vasopressin, which has a preferable adverse effect profile, however, its optimal dose and route of administration is unknown. We aimed to compare the pharmacodynamics and pharmacokinetics of various vasopressin doses administered via intravenous (IV), intraosseous (IO), endotracheal (ETT), and intranasal (IN) routes in healthy neonatal piglets. Forty-four post-transitional piglets (1–3 days of age) were anesthetized, intubated via a tracheostomy, and randomized to receive vasopressin via intravenous (control), IO, ETT, or IN route. Heart rate (HR), arterial blood pressure, carotid blood flow, and cardiac function (e.g., stroke volume, ejection fraction) were continuously recorded throughout the experiment. Blood was collected prior to drug administration and throughout the observation period for pharmacodynamics and pharmacokinetic analysis. Significant changes in hemodynamic parameters were observed following IO administration of vasopressin while pharmacokinetic parameters were not different between IV and IO vasopressin. Administration of vasopressin via ETT or IN did not change hemodynamic parameters and had significantly lower maximum plasma concentrations and systemic absorption compared to piglets administered IV vasopressin (p < 0.05). The IV and IO routes appear the most effective for vasopressin administration in neonatal piglets, while the ETT and IN routes appear unsuitable for vasopressin administration. [ABSTRACT FROM AUTHOR]

This study investigates the influence of body physiology on the rupture risk of cerebral saccular aneurysms. Comprehensive hemodynamic analyses were conducted using computational fluid dynamics to assess the potential for aneurysm rupture under three physiological conditions: rest, normal activity, and exercise. Contours of wall shear stress, oscillatory shear index, and pressure were analyzed and compared to identify regions at high risk of rupture. Additionally, statistical analysis was performed to evaluate the rupture risk of aneurysms. Blood flow dynamics during the peak systolic phase were also examined under these conditions. Our findings indicate that the dome area, where blood pressure is highest and the incoming blood flow first contacts the aneurysm sac, is the critical region with a heightened risk of rupture. [ABSTRACT FROM AUTHOR]

Computational models can be at the basis of new powerful technologies for studying and classifying disorders like pre-eclampsia, where it is difficult to distinguish pre-eclamptic patients from non-pre-eclamptic based on pressure when patients have a track record of hypertension. Computational models now enable a detailed analysis of how pregnancy affects the cardiovascular system. Therefore, new non-invasive biomarkers were developed that can aid the classification of pre-eclampsia through the integration of six different measured non-invasive cardiovascular signals. Datasets of 21 pregnant women (no early onset pre-eclampsia, n = 12; early onset pre-eclampsia, n = 9) were used to create personalised cardiovascular models through computational modelling resulting in predictions of blood pressure and flow waveforms in all major and minor vessels of the utero-ovarian system. The analysis performed revealed that the new predictors PPI (pressure pulsatility index) and RI (resistance index) calculated in arcuate and radial/spiral arteries are able to differentiate between the 2 groups of women (t-test scores of p <.001) better than PI (pulsatility index) and RI (Doppler calculated in the uterine artery) for both supervised and unsupervised classification. In conclusion, two novel high-performing biomarkers for the classification of pre-eclampsia have been identified based on blood velocity and pressure predictions in the smaller placental vasculatures where non-invasive measurements are not feasible. [ABSTRACT FROM AUTHOR]

Hyperemia in response to neural activity is essential for brain health. A hyperemic response delivers O2 and nutrients, clears metabolic waste, and concomitantly exposes cerebrovascular endothelial cells to hemodynamic forces. While neurovascular research has primarily centered on the front end of hyperemia—neuronal activity-to-vascular response—the mechanical consequences of hyperemia have gone largely unexplored. Piezo1 is an endothelial mechanosensor that senses hyperemia-associated forces. Using genetic mouse models and pharmacologic approaches to manipulate endothelial Piezo1 function, we evaluated its role in blood flow control and whether it impacts cognition. We provide evidence of a built-in brake system that sculpts hyperemia, and specifically show that Piezo1 activation triggers a mechano-feedback system that promotes blood flow recovery to baseline. Further, genetic Piezo1 modification led to deficits in complementary memory tasks. Collectively, our findings establish a role for endothelial Piezo1 in cerebral blood flow regulation and a role in its behavioral sequelae. On-demand blood flow increases are essential for brain health, but how flow recovers is unclear. Here, the authors show that brain perfusion triggers vascular Piezo1-mediated mechano-feedback that promotes blood flow recovery to baseline levels. [ABSTRACT FROM AUTHOR]

Purpose: Multiple factors have been shown to influence the rate of clinical pregnancy after FET in IVF treatment, including embryo quality, synchronization of embryo and endometrium, and endometrial receptivity (ER). The subendometrial blood flow conditions could also contribute potentially major effects toward the establishment and maintenance of pregnancy. We conducted a retrospective cohort study to examine the correlation between subendometrial blood flow, as determined by Doppler ultrasound, and pregnancy outcomes in IVF patients with a thin endometrium (endometrium thickness [EMT] ≤ 0.7 cm). Methods: This was a retrospective cohort study conducted at a university-affiliated reproductive hospital from January 2017 to April 2023. The EMT and subendometrial blood flows were assessed using transvaginal color Doppler ultrasound and evaluated by experienced clinical ultrasound physicians on the endometrial transformation day. The pregnancy outcomes were followed up and documented in clinical medical records through the IVF cohort study at our center. Results: In the patients with 0.5 cm ≤ EMT ≤ 0.7 cm, the embryo implantation rate was statistically significant increased in the patients with the presence of subendometrial blood flow (OR 1.484; 95% CI, 1.001–2.200; P = 0.049; aOR 1.425; 95% CI, 1.030–2.123; P = 0.003). Patients with discernible subendometrial blood flow have superior live birth (P = 0.028), clinical pregnancy (P = 0.049), and embryo implantation (P = 0.027) compared to the patients without subendometrial blood flow when the EMT is ≤ 0.7 cm. Conclusions: The presence of subendometrial blood flow detected by ultrasound was positively associated with successful embryo implantation and favorable pregnancy outcomes in patients with thin endometrium undergoing FET. [ABSTRACT FROM AUTHOR]

Introduction: Functional popliteal artery entrapment syndrome is a subtype of popliteal artery entrapment syndrome (PAES) without vascular disease or musculotendinous anomaly behind the knee. Symptoms are induced by popliteal artery extrinsic compression, leading to calf pain during lower limbs exercise. Non-invasive tests are still required to improve the diagnostic management of functional PAES. Exercise transcutaneous oxygen pressure (Ex-tcpO2) is of interest to provide objective arguments for the presence of regional blood flow impairment. Objectives: The aim of the study was to analyze whether Ex-tcpO2 could serve as a non-invasive technique for detecting ischemia resulting from PAES. Methods: Patients with suspected PAES were recruited between 2017 and 2020. The diagnosis was confirmed or rejected, according to the surgical decision based on our diagnosis management involving a multidisciplinary team. Each patient underwent Ex-tcpO2 with specific maneuvers. The decrease from rest of oxygen pressure (DROP) index served for the interpretation of exercise results. Results: Sixty-five legs with suspected PAES were recruited. Diagnosis was confirmed in 34 (52.3%) and rejected in 32 (47.7%). The average DROP values found in confirmed and rejected group at left leg were − 21.6 ± 15.4 mmHg and − 10.9 ± 11.1 mmHg, respectively (p for Mann–Whitney 0.004), and − 15.8 ± 11 mmHg and − 11.1 ± 7.5 mmHg, respectively, at right leg (p = 0.088). Ex-tcpO2 sensitivity and specificity were 52.9% and 78.1%, respectively. Conclusion: Ex-tcpO2 is an original non-invasive investigation for patients with claudication of doubtful arterial origin. The sensitivity and specificity are 52.9% and 78.1% in functional PAES diagnosis using 15 mmHg as threshold to detect ischemia during tiptoeing elevations. [ABSTRACT FROM AUTHOR]

Purpose: The involvement of central command in central hemodynamic regulation during exercise is relatively well-known, although its contribution to peripheral hemodynamics at the onset of low-intensity contractions is debated. This study sought to examine central and peripheral hemodynamics during electrically-evoked muscle contractions (without central command) and voluntary muscle activity (with central command). Methods: Cyclic quadriceps isometric contractions (1 every second), either electrically-evoked (ES; 200 ms trains composed of 20 square waves) or performed voluntarily (VC), were executed by 10 healthy males (26 ± 3 years). In both trials, matched for force output, peripheral and central hemodynamics were analysed. Results: At exercise onset, both ES and VC exhibited equal peaks of femoral blood flow (1276 ± 849 vs. 1117 ± 632 ml/min, p > 0.05) and vascular conductance (15 ± 11 vs. 13 ± 7 ml/min/mmHg, p > 0.05), respectively. Similar peaks of heart rate (86 ± 16 bpm vs. 85 ± 16 bpm), stroke volume (100 ± 20 vs. 99 ± 27 ml), cardiac output (8.2 ± 2.5 vs. 8.5 ± 2.1 L/min), and mean arterial pressure (113 ± 13 vs. 113 ± 3 mmHg), were recorded (all, p > 0.05). After ~ 50 s, all the variables drifted to lower values. Collectively, the hemodynamics showed equal responses. Conclusion: These results suggest a similar pathway for the initial (first 40 s) increase in central and peripheral hemodynamics. The parallel responses may suggest an initial minimal central command involvement during the onset of low-intensity contractions, likely associated with a neural drive activation delay or threshold. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the impact of short-term low energy availability (LEA) on vascular function in young, regularly menstruating women. Methods: Participants were 19 women, aged 22.9 ± 4.2 years, with body mass index 18–30 kg·m2. They were divided into two groups and completed two conditions in a crossover design: a 3-day control condition (CON) with an energy availability of 45 kcals·kgFFM−1·day−1 and a 3-day LEA condition of 15 kcals·kgFFM−1 day–1. Assessments were conducted during the early follicular phase of the menstrual cycle. Outcome measures included forearm blood flow (FBF), heart rate, blood pressure, arterial stiffness, resting energy expenditure (REE), metabolic blood markers and body composition. Results: Significant time-by-condition interactions were found for resting FBF (p =.004), REE (p =.042), triiodothyronine (p =.006), β-hydroxybutyrate (p =.002) and body mass (p <.001). Resting FBF was 1.43 ± 1.01 and 1.31 ± 0.61 (arbitrary units) at pre and post, respectively, in LEA and 1.52 ± 0.7 and 1.76 ± 0.57 at pre and post in CON. The LEA condition led to a decrease in triiodothyronine (pre: 1.54 ± 0.28, post: 1.29 ± 0.27 ng ml−1), REE (pre: 1588 ± 165, post: 1487 ± 160 kcals day−1) and body mass (pre: 61.4 ± 7.5, post: 59.6 ± 7.3 kg). Changes in resting FBF were significantly correlated with changes in REE in the LEA condition (r = 0.53; p = 0.02). Conclusion: Short-term LEA modifies regional blood flow and this might contribute to the observed decreased in REE. Findings emphasize the need for careful management of energy availability in populations at risk of LEA. [ABSTRACT FROM AUTHOR]

Secondary flow path is one of the crucial aspects during the design of centrifugal blood pumps. Small clearance size increases stress level and blood damage, while large clearance size can improve blood washout and reduce stress level. Nonetheless, large clearance also leads to strong secondary flows, causing further blood damage. Maglev blood pumps rely on magnetic force to achieve rotor suspension and allow more design freedom of clearance size. This study aims to characterize turbulent flow field and secondary flow as well as its effects on the primary flow and pump performance, in two representative commercial maglev blood pumps of CH-VAD and HeartMate III, which feature distinct designs of secondary flow path. The narrow and long secondary flow path of CH-VAD resulted in low secondary flow rates and low disturbance to the primary flow. The flow loss and blood damage potential of the CH-VAD mainly occurred at the secondary flow path, as well as the blade clearances. By contrast, the wide clearances in HeartMate III induced significant disturbance to the primary flow, resulting in large incidence angle, strong secondary flows and high flow loss. At higher flow rates, the incidence angle was even larger, causing larger separation, leading to a significant decrease of efficiency and steeper performance curve compared with CH-VAD. This study shows that maglev bearings do not guarantee good blood compatibility, and more attention should be paid to the influence of secondary flows on pump performance when designing centrifugal blood pumps. [ABSTRACT FROM AUTHOR]

Objectives: To investigate microvascular changes in juvenile localised scleroderma (JLS) lesions using superb microvascular imaging (SMI) and assess SMI's utility in evaluating disease activity. Methods: This prospective study enroled 16 children (7 males) with pathologically diagnosed JLS between January 2021 and June 2023. Lesions were assessed using Localised Scleroderma Cutaneous Assessment Tools, including the localised scleroderma skin activity index (LoSAI) and localised scleroderma skin damage index (LoSDI). Lesions with LoSAI scores > 0 were classified as active. The thickness and blood flow of the lesions and healthy skin layers of the contralateral site were evaluated using ultrasound. SMI was used to detect microvascular blood flow in the lesions and healthy skin, and the vascular index (VI) was calculated. The difference in VI between active lesions and healthy skin was correlated with LoSAI and total scores. Results: Of 46 lesions, 23 were active and 23 inactive. The skin thickness of the lesion was 0.094 ± 0.024 cm, and that of the healthy site was 0.108 ± 0.026 cm (p < 0.001). The VI of the active lesions and healthy skin were 7.60 (3.60, 12.80)% and 1.10 (0.50, 2.10)%, respectively (p < 0.001). The VI of the inactive lesions and the healthy skin were 0.85 (0.00, 2.20)% and 1.60 (1.00, 3.10)%, respectively (p = 0.011). VI differences between active lesions and healthy skin positively correlated with the LoSAI clinical score (r = 0.625, p = 0.001) and total score (r = 0.842, p < 0.001). Conclusion: SMI can quantitatively detect microvascular blood flow changes in JLS skin, indicating lesion activity and severity. Clinical relevance statement: SMI is a convenient, non-invasive, technique for detecting active JLS lesions and can provide valuable information to guide treatment options. Key Points: Current grading systems of juvenile localised scleroderma rely on subjective clinical information. Superb Microvascular Imaging identified that vascular indexes between active lesions and healthy skin positively correlated with clinical scores. Superb Microvascular Imaging effectively assesses microvascular blood flow, aiding juvenile localised scleroderma lesion activity evaluation. [ABSTRACT FROM AUTHOR]

This study investigates the intricate relationships that exist between electro-osmosis, permeability, and tapering effects in the flow characteristics of a copper nanofluid via a composite stenosed artery. Gaining further insight into the intricate interactions of permeability, electro-osmosis, and tapering in stenosed arteries will help enhance treatment regimens. By changing these parameters, interventions can be modified for improved fluid dynamics and nanoparticle transport, improving the care of cardiovascular health. For a better understanding of the main issue, a few constraints are taken into consideration, such as minor stenosis and low Reynolds numbers. Using an exact method, a set of simplified equations has been solved. In order to investigate the parametric influence of the physical elements on the flow properties, graphs have been constructed. It is found that the walls’ shear stress decreases the function of the slip parameter and permeability. It is also noted that for the trapping, boluses are shrunk in size with the factor named as absorption parameter but expanded in case of tapering angle. [ABSTRACT FROM AUTHOR]

Well-functioning vascular access (VA) is essential for hemodialysis treatment in patients with end-stage renal disease (ESRD). However, continuous and accurate monitoring of blood flow to assess high-flux VA during hospitalization or at home is not feasible for either clinical instruments or wearable sensors. Here, we report the design and preclinical validation of a high-precision, long-term, epidermal blood flow sensor that self-adapts to unavoidable sensor-mounting deviations on the skin and is compatible with individual tissue differences. Specifically, the technology is based on thermal dissipation of the skin, and improves the signal-to-error ratio surpassing 4 times when measuring high-flux blood (100–600 mL/min). In preclinical validation, the sensor is compared with the Doppler ultrasound and demonstrate a blood flow resolution of 10–50 mL/min. Furthermore, it is highly-integrated and wearable, measuring 36 × 50 mm2. The sensor paves the way for accurate, convenient, high-flux blood monitoring, offering significant potential to extend the lives of patients with ESRD. [ABSTRACT FROM AUTHOR]

This study aimed to examine the effects of intensive antihypertensive treatment (AHT), i.e., systolic blood pressure target ≤ 140 mmHg, on cerebral blood flow, cerebral autoregulation, and orthostatic hypotension, in a representative population of frail older adults. Fourteen frail hypertensive patients (six females; age 80.3 ± 5.2 years; Clinical Frailty Scale 4–7; unattended SBP ≥ 150 mmHg) underwent measurements before and after a median 7-week AHT targeting SBP ≤ 140 mmHg. Transcranial Doppler measurements of middle cerebral artery velocity (MCAv), reflecting changes in cerebral blood flow (CBF), were combined with finger plethysmography recordings of continuous BP. Transfer function analysis assessed cerebral autoregulation (CA). ANCOVA analysed AHT-induced changes in CBF and CA and evaluated non-inferiority of the relative change in CBF (margin: -10%; covariates: pre-AHT values and AHT-induced relative mean BP change). McNemar-tests analysed whether the prevalence of OH and initial OH, assessed by sit/supine-to-stand challenges, increased with AHT. Unattended mean arterial pressure decreased by 15 mmHg following AHT. Ten (71%) participants had good quality TCD assessments. Non-inferiority was confirmed for the relative change in MCAv (95%CI: -2.7, 30.4). CA remained normal following AHT (P > 0.05), and the prevalence of OH and initial OH did not increase (P ≥ 0.655). We found that AHT in frail, older patients does not reduce CBF, impair autoregulation, or increase (initial) OH prevalence. These observations may open doors for more intensive AHT targets upon individualized evaluation and monitoring of hypertensive frail patients. Clinical Trial Registration: This study is registered at ClinicalTrials.gov (NCT05529147; September 1, 2022) and EudraCT (2022-001283-10; June 28, 2022). [ABSTRACT FROM AUTHOR]

We investigate the influence of scleral cautery during cataract surgery on limbal vascular density and remodeling using anterior segment optical coherence tomography angiography (AS-OCTA). Twenty eyes of 20 patients who underwent cataract surgery with a sclerocorneal incision were included. Patients were divided into two groups: non-cautery (n = 10) and cautery (n = 10). The area around the incision site was scanned using AS-OCTA before surgery and at 1, 3, 5, 7, 14, 21, 28, and 90 days postoperatively. Images were analyzed to depict conjunctival vasculature (surface to a depth of 200 μm) and intrascleral vasculature (depth of 200 to 1000 μm). Vascular density was evaluated using ImageJ software. In the non-cautery group, intrascleral vascular density significantly increased during the wound-healing period up to 21 days postoperatively. Cautery application completely diminished this effect, resulting in significantly reduced intrascleral vascular density in the cautery group compared to the non-cautery group until 5 days after surgery. On the seventh day and later, intrascleral vascular density in the cautery group recovered, but the vascular pattern did not return to its preoperative state even at 90 days after surgery. Conjunctival flap vascular density was reduced for 28 days after surgery, with cautery application further decreasing conjunctival vascular density. AS-OCTA enabled separate observation of conjunctival and intrascleral vasculature. Intrascleral blood flow significantly increased after cataract surgery, but scleral cauterization markedly blocked this effect. The vascular reconstruction process following cataract surgery continued for almost a month, with cautery application leading to prolonged vascular disruption and altered vascular patterns. [ABSTRACT FROM AUTHOR]

Long-term and high-precision intracranial biomarker monitoring is crucial for the diagnosis, prevention, and prognosis of various diseases. However, existing technologies are associated with several issues of poor measurement accuracy, inability to monitor long-term and inadequate biocompatibility. To address these, minimally invasive implantable ultrasound metagel sensors have been developed for monitoring intracranial pressure, temperature, pH, and blood flow velocity. The sensor can quickly respond to changes in ultrasound frequency for high-precision monitoring of key physiological signals compared to current clinical gold standards. Additionally, the hydrogel exhibits excellent biocompatibility and can degrade almost completely within 18 weeks, without causing hematological disorders or systemic inflammatory responses. Highlights: • Significance, challenge, and existing technologies of intracranial biomarker monitoring. • Design and characterization of ultrasound-sensitive metagel sensors for multimodal intracranial biomarker monitoring. • Conclusions and perspectives on the future development of intracranial biomarker monitoring. [ABSTRACT FROM AUTHOR]

Pachychoroid spectrum disease (PSD) involves various chorioretinal pathologies associated with increased choroidal blood flow. Theoretically, PSD could worsen after cataract surgery since the choroidal thickness tends to increase after surgery. Therefore, we evaluated the prevalence of asymptomatic PSD in patients who underwent cataract surgery and compared the clinical characteristics according to the presence of PSD. The subretinal fluid (SRF) development risk was evaluated using the Cox proportional hazard model. Of 924 eyes, 184 (19.9%) showed asymptomatic PSD. Patients with asymptomatic PSD were older, predominantly male, hyperopic, and showed thicker choroid (P < 0.001, 0.001, < 0.001, and < 0.001). Seven (3.8%) of 184 eyes with asymptomatic PSD developed SRF. The Cox proportional hazard model showed that the flat, irregular pigment epithelial detect (FI-PED; HR 37.337, 95% CI 3.880–359.9300, P = 0.002) was the sole indicator for the SRF development after adjustment of age, sex, and axial length. The SRF-developed PSD group experienced a profound and prolonged increase in the choroidal thickness (P = 0.001, 0.002, and 0.002 at 1, 3, and 12 months). Meticulous preoperative evaluation for FI-PED and postoperative monitoring for choroidal thickness would predict SRF development after cataract surgery in eyes with asymptomatic PSD. [ABSTRACT FROM AUTHOR]

Transarterial chemoembolization (TACE) is an image-guided minimally invasive treatment for liver cancer which involves delivery of chemotherapy and embolic material into tumor-supplying arteries to block blood flow to a liver tumor and to deliver chemotherapy directly to the tumor. However, the released drug diffuses only less than a millimeter away from the beads. To enhance the efficacy of TACE, the development of microbubbles electrostatically bound to the surface of drug-eluting beads loaded with different amounts of doxorubicin (0–37.5 mg of Dox/mL of beads) is reported. Up to 400 microbubbles were bound to Dox-loaded beads (70–150 microns). This facilitated ultrasound imaging of the beads and increased the release rate of Dox upon exposure to high intensity focused ultrasound (HIFU). Furthermore, ultrasound exposure (1 MPa peak negative pressure) increased the distance at which Dox could be detected from beads embedded in a tissue-mimicking phantom, compared with a no ultrasound control. [ABSTRACT FROM AUTHOR]

Neurovascular coupling (NVC), which mediates rapid increases in cerebral blood flow in response to neuronal activation, is commonly used to map brain activation or dysfunction. Here we tested the reemerging hypothesis that CO2 generated by neuronal metabolism contributes to NVC. We combined functional ultrasound and two-photon imaging in the mouse barrel cortex to specifically examine the onsets of local changes in vessel diameter, blood flow dynamics, vascular/perivascular/intracellular pH, and intracellular calcium signals along the vascular arbor in response to a short and strong CO2 challenge (10 s, 20%) and whisker stimulation. We report that the brief hypercapnia reversibly acidifies all cells of the arteriole wall and the periarteriolar space 3–4 s prior to the arteriole dilation. During this prolonged lag period, NVC triggered by whisker stimulation is not affected by the acidification of the entire neurovascular unit. As it also persists under condition of continuous inflow of CO2, we conclude that CO2 is not involved in NVC. A remerging hypothesis suggests that CO2 generated by neuronal metabolism contributes to neurovascular coupling (NVC). Here, the authors show that NVC is unaffected by the acidification of the entire arteriolar column during cerebrovascular reactivity to CO2, demonstrating that CO2 is not a mediator of NVC. [ABSTRACT FROM AUTHOR]

Aim: The purpose of the present study was to evaluate the diagnostic performance of serum miR-4534 combined with Transvaginal Color Doppler Ultrasound (TVCDS) in cervical cancer patients. Methods: Blood samples from 126 patients with cervical cancer and 83 patients with benign uterine lesions were retrospectively analyzed. Quantitative real time polymerase chain reaction (qRT-PCR) was applied to examine the relative abundances of serum miR-4534 in cervical cancer based on a case–control study. Chi-square test was adopted to analyze the association between serum miR-4534 and other clinicopathological factors. The blood flow of cervix was examined using TVCDS, and the blood flow resistance index (RI) of cervix was summarized. Receiver operating characteristic (ROC) curves were plotted to explore the diagnostic capacity of serum miR-4534 combined with blood flow RI. Logistic regression was employed to analyze the risk factors of cervical cancer. Results: Serum miR-4534 was distinctly increased in the study group compared with the control group (P < 0.05), while blood flow RI was dramatically decreased (P < 0.05). Moreover, increased miR-4534 was closely associated with lymph node metastasis (P = 0.010), FIGO stage (P = 0.007) and HR-HPV (P = 0.025). ROC curves demonstrated that the area under curve (AUC) of serum miR-4534 combined with the blood flow RI was 0.854, with the sensitivity and specificity of 88.9% and 73.5%, respectively, which displayed a better diagnostic capacity than serum miR-4534 and blood flow RI alone. Logistic regression analysis demonstrated that serum miR-4534 (OR = 8.805, 95% CI = 4.124–18.798; P < 0.001) was a risk factor related to the initiation and formation of cervical cancer, as well as blood flow RI (OR = 0.112; 95% CI = 0.054–0.235; P < 0.001). Conclusion: Serum miR-4534 was highly expressed in cervical cancer, and associated with the development and metastasis of cervical cancer patients. MiR-4534 combined with TVCDS exhibited a considerable biomarker to detect cervical cancer patients. [ABSTRACT FROM AUTHOR]

Elastomeric interphases (liners) protect the residual limb and distribute mass bearing to the prosthetic socket. However, discomfort due to excessive sweat and heat in the residual limb is the most relevant factor that negatively affects the quality of life in transfemoral prosthetics users. Additionally, a warm and humid environment and the non-uniform mass distribution can compromise blood flow in the residual limb; these factors favor the development of skin lesions, the dropout rate of prosthetic use, and subsequent amputations. Previous mathematical models that predict skin temperature distribution based on Pennes' model and explain the Fourier and non-Fourier thermic response are available. However, these models require knowledge of difficult parameters to obtain in conditions that lead to amputation. Therefore, the current study aims to propose an experimentally based method to design a personalized liner with areas of different diffusivity rates by using perforations according to thermal needs, preserving the mechanical properties of the liner. After thermal and mechanical characterization, we elaborated a personalized plane liner according to the thermal expression of the anterior thigh using infrared analysis. We tested the liner to probe its ability to dissipate heat. [ABSTRACT FROM AUTHOR]

Purpose: This study is to evaluate the correlation between retrobulbar perfusion deficits and glaucomatous visual field defects. Methods: Eighty-four patients with glaucoma and 17 normal subjects serving as controls were selected. Color Doppler imaging (CDI) was used to measure the changes in blood flow parameters in the retrobulbar ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs). Visual field testing was performed using a Humphrey perimeter, categorizing the visual field deficits into four stages according to the Advanced Glaucoma Intervention Study (AGIS) scoring method. Subsequently, the correlation of retrobulbar hemodynamic parameter alterations among glaucomatous patients with varying visual field defects was examined. Results: The higher the visual field stage, the lower the peak systolic velocity (PSV) of the OA, CRA, and SPCAs in glaucomatous patients. The CRA had the highest sensitivity to changes in its PSV. The PSV of the temporal SPCA (TSPCA-PSV) was lower in advanced glaucoma than in early-stage glaucoma. The PSVs of the OA, CRA, and TSPCA, as well as the resistance index of the CRA (CRA-RI), were positively correlated with the visual field index and the mean deviation. Except for that of OA, the PSV of the retrobulbar vessels was negatively correlated with the pattern standard deviation (PSD). The OA-PSV and end-diastolic velocity (EDV) of the CRA and TSPCA were lower in patients with superior visual field defects than in those with inferior visual field defects. Conclusions: Greater severity of visual field defects corresponded to poorer retrobulbar blood flow in glaucomatous patients. Patients suffered significant perfusion impairments in the CRA at the early stage, accompanied by SPCA perfusion disorder at the advanced stage. The presence of a bow-shaped defect in the superior or inferior region of the visual field in moderate-stage glaucoma was closely correlated with retrobulbar vascular EDV. Trial registration: ChiCTR2200059048 (2022–04-23). [ABSTRACT FROM AUTHOR]

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Entropy generation in the human circulatory system represents the natural energy dissipation and transformation processes within the complex blood vessel network. This phenomenon has captivated the attention of biomedical engineers, clinicians, and medical scientists due to its potential to provide valuable insights into complex physiological and pathological conditions, such as cardiovascular diseases, thrombosis, and hemodynamic disorders. This present study illustrates the interplay between entropy generation, electro-magnetic field, and thermal radiation in bio-magnetic ternary hybrid nanofluid flow over non-linearly heated stretched sheet with porosity and Darcy-Forchheimer. The novelty of this research lies in introducing a comprehensive analysis of entropy generation in a bio-magnetic ternary hybrid nanofluid, incorporating the combined effects of multiple nanoparticles (Cu, Au, Ti) to enhance thermal conductivity and optimize biomedical applications. This study introduced a novel approach utilizing a multi-layer artificial neural network (ANN) with the MLP feed-forward backpropagation and Levenberg–Marquardt algorithm to effectively model entropy generation in bio-magnetic fluid flow. A comprehensive dataset was meticulously gathered and processed to ensure accurate testing, validation, and training of the ANN model. Furthermore, nonlinear mathematical equations governing variables like velocity, temperature, skin friction coefficient, and rate of heat transfer are rigorously resolved using the bvp4c solver in MATLAB. The impact of the active parameters in the flow dynamics of the bio-magnetic flow is effectively showcased through suitable tables and graphs, providing a visual representation of their influence. The variable of wall thickness influences the rise of the electric field, resulting in an observed intensification in the velocity profile. Increases in the volume fraction of nanoparticles result in higher levels of entropy generation and Bejan number. Skin friction coefficient decreases by approximately 0.49%, 0.99%, 1.50%, and 2.01% for E = 0.04, 0.06, 0.08, and 0.1, respectively. Rate of heat transfer increases by approximately 4.8%, 9.1%, 12.8%, and 16.1% for ϕ = 0.01 , 0.02 , 0.03 , and 0.04, respectively. [ABSTRACT FROM AUTHOR]

This article examines the behavior of blood when exposed to gold and copper nanoparticles. The assumption is made that the blood flow is incompressible as a result of the influence of electro-magnetohydrodynamic phenomena. The fluid is undergoing propagation inside an artery that is experiencing stenosis. Additional elements, such as viscous dissipation, heat production or absorption effects, and convection processes, are also considered. The mathematical modeling has been conducted using the energy and momentum equations. The resultant equations are solved analytically using the perturbation technique, and solutions are shown up to third-order approximations. The present study presents a discussion on the computational findings pertaining to the velocity profile, wall shear stress, impedance profile, and thermal profile. Furthermore, the use of streamlines has also been employed to examine trapping processes. The findings obtained from this study have significant ramifications, which might potentially bring about a transformative shift in the field of biomedical applications and treatments, namely in the realm of cardiovascular medicine. It has been noticed that when heat is introduced, the arterial walls undergo slight expansion. This expansion increases the cross-sectional area of the stenosed region, thereby reducing the constriction and lowering impedance. This study contributes to the advancement of knowledge by examining the behavior of blood in stenosed arteries when hybrid copper–gold nanoparticles are present. By doing so, it creates a basis for the development of novel and focused strategies to tackle cardiovascular diseases specifically in the context of stenosis. [ABSTRACT FROM AUTHOR]

Purpose: A blood pressure stabilization during late phase II of Valsalva's maneuver may be utilized to confirm sympathetic vasoconstrictor control after a spinal cord injury. This study investigated whether Valsalva response was predictive of hemodynamics during tilt or isometric handgrip. Methods: Presence/absence of Valsalva response was compared to heart rate, mean arterial pressure, leg blood flow, and vascular resistance during head-up tilt and isometric handgrip to fatigue in 14 adults with spinal cord injury from C7 to T12 and 14 controls. Statistics were performed with two-way repeated measure analysis of variance (ANOVA), post hoc t-tests for between-group comparisons, and Mann–Whitney U tests for within-group. Results: In total, six participants with spinal cord injury lacked a blood pressure stabilization for Valsalva's maneuver. However, this was not related to vasoconstrictor responses during the other tests. The groups had similar heart rate and blood pressure changes during tilt, though leg blood flow decreases and vascular resistance increases tended to be smaller at 20° tilt in those with spinal cord injury (p = 0.07 and p = 0.11, respectively). Participants with spinal cord injury had lower heart rates and markedly smaller blood pressure increases during handgrip (both p < 0.05). There were no group differences in leg blood flow, but those with spinal cord injury demonstrated a blunted vascular resistance increase by the final 10% of the handgrip (p < 0.01). Conclusions: Valsalva response was not consistent with hemodynamics during other stimuli, but some individuals evidence increases in sub-lesional vascular resistance to isometric handgrip comparable to controls, suggesting a sympathoexcitatory stimulus may be critical to provoke hemodynamic responses after spinal cord injury. [ABSTRACT FROM AUTHOR]

As a difficult-to-treat neurological condition, cerebral ischemia is currently limited to treatments such as intravenous recombinant tissue plasminogen activator thrombolysis and thrombectomy. Metformin, a potent antidiabetic drug, has been reported to have an independent function in enhancing the prognosis of stroke patients, in addition to its glucose-lowering effects. However, the mechanism of action of metformin in this context remains unclear. In vivo, a rat model of permanent middle cerebral artery occlusion was established, and after administration of a low dose of 10.5 mg/mL metformin, infarct area was measured by TTC staining, and cortical blood flow was determined by laser Doppler imaging. In vitro, the study established human umbilical vein endothelial cells treated with cobalt chloride. Immunofluorescence, immunohistochemistry, and Western blot experiments were performed to observe the expression of angiogenic factors, tight junction proteins, and apoptotic factors. A TUNEL assay was utilized to appraise cell death by apoptosis. A tube formation assay and scratch assay were conducted to determine the endothelial neovascularization status. Animal experiments have revealed that the administration of the AMPK activator metformin significantly reduced the infarct area, promoted the expression of angiogenic factors, and maintained the stability of tight junction proteins in endothelial cells. Moreover, metformin reduces nerve cells apoptosis by affecting the expression of the apoptotic protein cleaved-caspase3 via the HIF-1α pathway. In vitro, the LKB1/AMPK signaling pathway is activated after hypoxic stimulation, attaining its peak within the early stages of hypoxia (1–12 h) and gradually weakening thereafter. The administration of AMPK pharmacological agonists (between 36 and 48 h) can enhance AMPK activity, which can lead to the expression of angiogenic factors, maintain the stability of tight-junction proteins in endothelial cells, and facilitate endothelial cell migration and vascular structure formation. Conversely, the AMPK inhibitors exert the opposite effects. The activation of the LKB1/AMPK/HIF-1α signaling pathway by metformin in cerebral ischemia contributes to angiogenesis, promotes tissue repair in the injured area, and enhances neurologically functional symptoms. [ABSTRACT FROM AUTHOR]

Coronary arteries serve a crucial purpose in the circulatory system as they supply blood to the human heart, a highly oxidative organ. As the blood flows through these arteries, the constituents of blood such as proteins and fatty acid molecules may start depositing on the arterial lining. These depositions narrow down the arteries and obstruct the blood flow to the heart. This phenomenon is termed as atherosclerosis, responsible for coronary artery disease, a leading cause of death globally. The progression of disease is affected by coronary hemodynamics which strongly depends on the geometrical complexities such as branching and tapering, and the associated parameters such as curvature and tortuosity. These geometrical parameters vary across the population and are affected by factors such as dietary habits, gender, lifestyle and genetics. Technological advancements in the past few decades have resulted in emergence of patient-specific computational fluid dynamics (CFD) modelling as an important tool in cardiovascular engineering and technology. Patient-specific CFD modelling utilises the clinically obtained patient-specific geometrical and boundary condition data to model the flow and gain an insight in the detailed hemodynamic behaviour, calculate different parameters which can be used as biomarkers and assess different treatment options. In this article, we provide a brief overview of the human coronary circulation and typical steps involved in patient-specific modelling. Further, the studies on patient-specific coronary hemodynamics are extensively reviewed and a perspective on future trends is provided. We believe that the article will serve as a beginner's guide for the researchers working in this emerging area. [ABSTRACT FROM AUTHOR]

Background: Treatment of complex wide neck internal carotid aneurysm is technically difficult with both surgical as well as endovascular therapy. In this study, we work with flow diverter device to construct vascular lumen which diverts the blood flow from aneurysm sac. Case presentation: We report on two patients with two complex wide neck ruptured aneurysms located in the internal carotid artery associated with two small aneurysms who presented with severe headache and vomiting. All aneurysms were treated with single Surpass Evolve flow diverter (SE-FD) placement. Post-procedural clinical and angiographic outcomes were evaluated Conclusion: This study shows that Surpass Evolve flow diverter is safe and validity for management of complex wide neck internal carotid artery aneurysm and able to terminate all blister aneurysms associated with the parent artery. [ABSTRACT FROM AUTHOR]

Background: Performing reproducible flow-mediated dilatation (FMD) measurements can be challenging, especially among inexperienced operators. Our aim was to present the detailed learning curve of a novice operator. Methods: Following a one-week basic training period, the operator performed duplicate measurements on 6–8 individuals per week, for six weeks. The operator followed the recommendations of the most recent guideline. Duplex ultrasound was used for the simultaneous and continuous measurement of brachial artery diameter and local blood flow velocity. Following a 1-min recording of baseline diameter (D), FMD was measured after a 5-min period of occlusion of the proximal forearm vessels. Inter-session coefficient of variation (CV) values for D and FMD were calculated for each week. Results: The number of volunteers assessed each week were the following: 8, 7, 7, 6, 7, 7 individuals. CV values for both D and FMD exhibited a decreasing trend over the training period, ending at 1.73% for D and 14.24% for FMD at week 6. These CV values are within the range outlined in the most recent FMD guideline for proficiency. Conclusion: Within a reasonable timeframe, and with careful adherence to measurement guidelines, the attainment of sound reproducibility in FMD measurements by a novice operator is feasible. [ABSTRACT FROM AUTHOR]

Background/purpose: Living donor liver transplantation (LDLT) is vital for pediatric end-stage liver disease due to organ shortages. The graft-to-recipient weight ratio (GRWR) preoperatively measured predicts the outcomes of LDLT. We typically target between 0.8 and 3.0–4.0%, but the ideal GRWR remains controversial. We compared the outcomes of LDLT according to the GRWR to examine whether the criteria could be expanded while ensuring safety. Methods: We retrospectively reviewed 99 patients who underwent LDLT in our department by dividing them into three groups according to their GRWR: Group S, with GRWR values lower than the normal range (GRWR < 0.8%); Group M, with GRWR values in the normal range (GRWR ≥ 0.8 to < 3.5%); and Group L, with GRWR values above the normal range (GRWR ≥ 3.5%). Results: In Groups S and L, 46.2 and 44.4% of patients underwent splenectomy and delayed abdominal wall closure, respectively. After these intraoperative adjustments, there were no significant differences between the groups in 5-year patient survival, 5-year graft survival, or the occurrence of post-transplantation thrombosis. Conclusion: When the GRWR is beyond the normal threshold, the risk of complications associated with graft size might be reduced by adjustments to provide appropriate portal blood flow and by delayed abdominal wall closure. [ABSTRACT FROM AUTHOR]

Imaging and characterizing the dynamics of cellular adhesion in blood samples is of fundamental importance in understanding biological function. In vitro microscopy methods are widely used for this task but typically require diluting the blood with a buffer to allow for transmission of light. However, whole blood provides crucial signaling cues that influence adhesion dynamics, which means that conventional approaches lack the full physiological complexity of living microvasculature. We can reliably image cell interactions in microfluidic channels during whole blood flow by motion blur microscopy (MBM) in vitro and automate image analysis using machine learning. MBM provides a low cost, easy to implement alternative to intravital microscopy, for rapid data generation where understanding cell interactions, adhesion, and motility is crucial. MBM is generalizable to studies of various diseases, including cancer, blood disorders, thrombosis, inflammatory and autoimmune diseases, as well as providing rich datasets for theoretical modeling of adhesion dynamics. Monitoring cellular adhesion in blood samples is of fundamental importance, but conventional approaches may not capture the full physiological complexity of microscale flow in living contexts. Here, the authors present motion blur microscopy and machine learning-based image analysis to study cell interactions in microfluidic channels during whole blood flow. [ABSTRACT FROM AUTHOR]

Nonthrombotic iliac vein lesions (NIVLs) are significant causes of chronic venous insufficiency (CVI) in the left lower limb and symptom recurrence following left lower limb varicose vein treatment. The goal of this study was to explore the haemodynamic and morphological characteristics of iliac veins in patients with NIVLs. Pressure at the caudal end of the stenotic left common iliac vein (LCIV) segment, local blood flow velocity, and time-averaged wall shear stress in the stenotic segment exhibited positive correlations with the clinical CVI classification (R = 0.92, p < 0.001; R = 0.94, p < 0.001; R = 0.87, p < 0.001), while the relative retention time showed a negative correlation (R = -0.94, p < 0.001). The pressure difference (∆P) between the two ends of the stenotic segment and the velocity difference (∆V) between the stenotic segment and the caudal end were positively correlated with the clinical classification (R = 0.92, p < 0.001; R = 0.9, p < 0.001). The cross-sectional area stenosis rate and length of the stenotic LCIV segment were positively correlated with the clinical classification (R = 0.93, p < 0.001; R = 0.63, p < 0.001). The results suggest that haemodynamic assessment of the iliac vein could effectively portray blood flow disturbances in stenotic segments of the LCIV, potentially reflecting the degree of iliac vein stenosis. Haemodynamic indicators are correlated with the severity of clinical CVI symptoms. [ABSTRACT FROM AUTHOR]

The complications anticipated in the postoperative period after surgical resection of lateral ventricular neoplasms (LVN) are hemorrhage, hydrocephalus. At the N.N. Burdenko Neurosurgery Center, 48 patients with LVN underwent surgical resection. We focused on the correlation between approaches to the ventricular system on one hand and the extent of resection and incidence of complications on the other based on anatomical and perfusion characteristics estimated via preoperative magnetic resonance imaging (MRI) with arterial spin labeling perfusion. By eliminating the surgical approach as a potential risk factor, we were able to demonstrate the correlation between the frequency of postoperative hemorrhage, the Evans index value, patient's gender, tumor blood flow (nTBF) and the location of the mass in the anterior horn of the lateral ventricle. The risk of hemorrhage depends on the patient's gender, presence of hydrocephalus, location of the mass and tumor blood flow values. The risk increases along with increase in Evance index and nTBF values. [ABSTRACT FROM AUTHOR]

Purpose: Using ex vivo normothermic machine perfusion (NMP) with whole blood we assessed marginal porcine kidneys under reperfusion. The aim was to link measureable machine and clinical blood parameters with the currently used visual assessment. This could serve as a baseline for a standardized evaluation score to identify potentially transplantable kidneys in the future. Methods: Kidneys and autologous whole blood were procured from slaughterhouse pigs (n = 33) and were perfused for 4 h using NMP. The hemodynamic parameters arterial pressure (AP), renal blood flow (RBF) and intrarenal resistance (IRR) were measured. Activity of aspartate transaminase (AST), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and lactate were assessed in blood at 0/1/2/4 h. Kidneys were grouped into "potentially transplantable" (PT) or "not transplantable" (NT) based on their overall macroscopic appearance after NMP by an experienced physician. Results: PT-kidneys (n = 20) had a significantly lower IRR and higher RBF than NT-kidneys (n = 13). GGT, ALP and LDH did not differ significantly, but at 4 h, AST was significantly higher in PT-kidneys compared to NT-kidneys. Lactate levels kept increasing during NMP in NT-kidneys and were significantly higher at 1/2/4 h than in PT-kidneys. Conclusion: The immediately assessed macroscopic aspects of examined kidneys correlated with hemodynamic parameters, increased lactate and lower AST in this study. In the future, NMP with whole blood could be a useful tool to extend the donor pool by allowing the assessment of otherwise unknown characteristics of marginal kidneys before transplantation. [ABSTRACT FROM AUTHOR]

Thrombosis is the formation of abnormal blood clots in the blood vessels that obstruct blood flow and lead to thrombosis. Current treatments for thrombosis are associated with serious side effects. Therefore there is a need for alternative natural therapy. A fibrinolytic protease was isolated from fresh leaves of Moringa oleifera Lam. and characterized for its potential to solubilize blood clots and hydrolyse fibrin under in-vitro conditions. The isolated protease showed a single protein band on native-PAGE. It showed optimum fibrinolytic activity at pH 8.0, 37 oC with 50 µg protein. The fibrinolytic activity of isolated protease was also confirmed by fibrin zymography. Km and Vmax of isolated protease were determined by the Lineweaver Burk plot. The isolated protease could solubilize 96.41% of blood clots by 96 h under in-vitro conditions. In-vitro fibrin hydrolysis and blood clot solubilization activities shown by an isolated protease from leaves of Moringa oleifera Lam. suggest its fibrinolytic potential to dissolve blood clots. Being a natural molecule and from a dietary plant it can be explored as an alternative natural therapy against thrombosis. [ABSTRACT FROM AUTHOR]

The neurochemical anatomy underlying Cushing's syndrome is examined for regional brain metabolism as well as neurotransmitter levels and receptor binding of biogenic amines and amino acids. Preliminary studies generally indicate that glucose uptake, blood flow, and activation on fMRI scans decreased in neocortical areas and increased in subcortical areas of patients with Cushing's syndrome or disease. Glucocorticoid-mediated increases in hippocampal metabolism occurred despite in vitro evidence of glucocorticoid-induced decreases in glucose uptake or consumption, indicating that in vivo increases are the result of indirect, compensatory, or preliminary responses. In animal studies, glucocorticoid administration decreased 5HT levels and 5HT1A receptor binding in several brain regions while adrenalectomy increased such binding. Region-specific effects were also obtained in regard to the dopaminergic system, with predominant actions of glucocorticoid-induced potentiation of reuptake blockers and releasing agents. More in-depth neuroanatomical analyses are warranted of these and amino acid-related neurotransmission. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether reduced tissue oxygen availability through blood flow restriction (BFR) alone, or in combination with electrically induced muscle contractions, can improve glucose clearance after an acute glucose challenge. Methods: In a randomized crossover design, 21 young participants (females: 12) were allocated to perform 1) electrical muscle stimulation (EMS), 2) BFR, 3) EMS + BFR or 4) no treatment (control). Participants completed each condition immediately preceding a 2 h oral glucose tolerance test (100 g). Primary analyses were performed on the glucose area under the curve (AUC) at time points 0–30, 30–120, and 0–120 min. Secondary analyses were performed on glycemic responses based on biological sex and estimated muscle phenotype. Results: Compared to the control (322±25 mM∙min), the 0-30 min AUC was reduced following EMS (293±22 mM∙min, p = 0.0004), and EMS + BFR (298±36 mM∙min., p = 0.006), whereas BFR in isolation did not differ (306±30 mM∙min, p = 0.1). The 30–120 and 0-120 min glucose AUCs were similar across conditions. Based on effect size from the control conditions, our secondary analysis suggests different 0–30 min glycemic responses after EMS + BFR between females (dz = 0.206) vs. males (dz = 1.461) and/or slow (dz = 0.426) vs. fast (dz = 1.075) muscle phenotype. Conclusion: Reducing tissue oxygen availability with BFR did not augment the effects of EMS in the overall group; however, we provide preliminary data to suggest possible sex and/or muscle phenotypic responses in glycemic regulation with these modalities. [ABSTRACT FROM AUTHOR]

The 3 × 3 blood flow dynamic model describes the flow of blood in flexible vessels. We study the inviscous blood flow in arteries model in this paper. The elementary waves of the blood flow in arteries include the rarefaction wave, the shock wave and the stationary wave which appears where the material properties of vessel wall change. The interactions of stationary wave with rarefaction wave and shock wave in arteries are discussed in detail. We focus on the changes of the cross-sectional area of the blood vessel and the averaged axial velocity of blood flow after the rarefaction wave and the shock wave penetrate the stationary wave. They change after interactions. [ABSTRACT FROM AUTHOR]

Objective: The wearing-off phenomenon is common in people with multiple sclerosis (MS) treated with ocrelizumab. We aim to evaluate the presence and severity of wearing-off to ocrelizumab in relation to demographic and MS clinical variables, immune profiling, and a marker of neuroaxonal damage (plasma neurofilament light chain (pNfl)). Methods: This cross-sectional study included MS patients treated with ocrelizumab from at least 1 year. Wearing-off questionnaire and blood samples were collected between 21 and 23 weeks after the previous ocrelizumab infusion. Lymphocyte subpopulations were evaluated on peripheral blood using flow cytometry. PNfl was evaluated using fully automated chemiluminescent enzyme immunoassay. Results: We included 106 people with MS (age 49.5 ± 11.6 years; females 42.3%; wearing-off 57.6%). On regression models, wearing-off was associated with higher pNfl, CD8, CD3, and CD3CD27 lymphocytes. Most frequent wearing-off symptoms were cognitive, sensory, and balance problems; wearing-off started < 1 week (9.4%), 1–4 weeks (10.7%) or > 4 weeks (10.7%) before infusion; 44.8% of the complaints were moderate to severe. Severity of wearing-off was associated with higher pNfl and CD8 lymphocytes. Conclusions: Wearing-off is common in people with MS treated with ocrelizumab, and is associated with reduced immunomodulation (higher T lymphocytes) and increased neuroaxonal damage, suggesting reduced treatment response. [ABSTRACT FROM AUTHOR]

Purpose: To retrospectively compare strength outcomes of individuals undergoing postoperative rehabilitation following quadriceps tendon (QT) autograft anterior cruciate ligament reconstruction (ACLR) with and without blood flow restriction therapy. Methods: A retrospective review of consecutive patients undergoing ACLR with QT autograft with a minimum of two quantitative postoperative isometric strength assessments via an electromechanical dynamometer (Biodex) was included. Demographics, surgical variables and strength measurement outcomes were compared between patients undergoing blood flow restriction therapy as part of postoperative rehabilitation versus those who did not. Results: Eighty‐one (81) patients met the inclusion criteria. No differences were found in demographic and surgical characteristics between those who received blood flow restriction compared with those who did not. While both groups had improvements in quadriceps peak torque and limb symmetry index (LSI; defined as peak torque of the operative limb divided by the peak torque of the nonoperative limb) over the study period, the blood flow restriction group had significantly lower mean peak torque of the operative limb at first Biodex strength measurement (95.6 vs. 111.2 Nm; p = 0.03). Additionally, the blood flow restriction group had a significantly lower mean LSI than those with no blood flow restriction at the second Biodex measurement timepoint (81% vs. 90%; p = 0.02). No other significant differences were found between the strength outcomes measured. Conclusions: Results of this study show that the 'real world' clinical implementation of blood flow restriction therapy to the postoperative rehabilitation protocol following QT autograft ACLR did not result in an increase in absolute or longitudinal changes in quadriceps strength measurements. A better understanding and standardisation of the use of blood flow restriction therapy in the rehabilitation setting is necessary to delineate the true effects of this modality on strength recovery after QT autograft ACLR. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]