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Background/Objectives: The aim of this study was to evaluate the choroidal vascular response using optical coherence tomography (OCT) in patients with chronic central serous chorioretinopathy (CSCR) during transient increases in blood pressure. Methods: This observational, case–control study enrolled chronic CSCR patients and age-matched healthy controls. OCT scans of the macula were performed at rest and during hand-grip (HG) isometric exercise. Mean ocular perfusion pressure (MOPP) and subfoveal choroidal thickness (SCT) were measured at baseline and during stress. Quantitative OCT assessment included the bright area (BA, stroma), dark area (DA, vascular lumen), and total choroidal area (CA). The choroidal vascularity index (CVI) was calculated as DA/CA to assess vascular response to stress. A comparative analysis between CSCR patients and controls was conducted. Conclusions: MOPP was significantly higher (p = 0.008) at baseline in CSCR patients and further increased under stress compared to controls. SCT and CA were both significantly higher in CSCR patients than in healthy subjects at rest and under stress (p < 0.001), but no change occurred after HG. A significant decrease in CVI (p = 0.005) was noted in controls under stress, but not in CSCR patients. Additionally, a negative correlation between CVI and MOPP was found in healthy subjects (−0.648; p = 0.043). The study demonstrated a choroidal vasoconstrictive response to stress in healthy subjects, as evidenced by a decrease in CVI, but not in CSCR patients. This suggests that CSCR patients may experience impaired choroidal blood flow regulation, resulting in potentially higher perfusion pressures during stress without compensatory vasoconstriction, potentially affecting the choriocapillaris. [ABSTRACT FROM AUTHOR]

Calcified areas in aortic valves often co-localize with amyloid fibrils that can promote calcification. Patient-derived amyloid fibrils contain arrays of acidic residues that can bind calcium and organize calcium phosphate nucleation clusters, while collagen fibrils guide crystal growth. This process is akin to functional biomineralization guided by Ca entrapment by acidic arrays in proteins, including amyloids. High shear stress and turbulent blood flow across the aortic valve, which are exacerbated in calcific aortic valve disease (CAVD), augment amyloid formation by plasma proteins. The main amyloid protein is probably apolipoprotein A-I (apoA-I), yet other proteins can also be involved. Lipoprotein(a) [Lp(a)], a genetic risk factor for CAVD, contributes to calcification. Enzymatic hydrolysis of oxidized phospholipids in Lp(a) helps generate orthophosphate, whereas apo(a) blocks collagen and amyloid fibril degradation by plasmin. Calcific aortic valve disease (CAVD) is a widely prevalent heart disorder in need of pharmacological interventions. Calcified areas in aortic valves often contain amyloid fibrils that promote calcification in vitro. This opinion paper suggests that amyloid contributes to CAVD development; amyloid-assisted nucleation can accelerate hydroxyapatite deposition onto collagen matrix. Notably, acidic arrays in amyloid match calcium–calcium spacing in the amorphous hydroxyapatite precursor, while oscillating hemodynamic perturbations promote amyloid deposition in the valve. Lipoprotein(a), a genetic risk factor for CAVD, augments calcification via several mechanisms, wherein hydrolysis of oxidized phospholipids (oxPLs) by Lp(a)-associated enzymes helps generate orthophosphate, and apolipoprotein(a) blocks plasmin-induced fibril degradation. Current studies of amyloid–calcium–collagen interactions in solution and in fibrillar complexes allow deeper insight into the role of amyloid in calcification. [ABSTRACT FROM AUTHOR]

BackgroudHeart responds to physiologic and pathologic conditions and sympathetic drive plays an important role. It has been documented that LV base is more dominantly affected by sympathetic drive compared to the other regions. LV base is more dominantly exposed to wall stress in the initial period of remodeling due to pressure-overload, since LV cavity is the largest at base. Basal septal hypertrophy (BSH) in cross-sectional data is associated with the early phase of hypertensive heart disease. BSH was confirmed by 3rd generation microscopic ultrasound in small animals. BSH as the closest location to increased afterload could be detected in variety of stress stimuli and result in a huge septal hypertrophy in advance cases possibly related to earlier exposure of hemodynamic stress to septal wall.ConclusionEffective geometric and functional evaluation of initial remodeling due to hemodynamic stress is important according to both human and animal data. These findings possibly contribute to early recognition of adaptive phase of hypertensive remodeling and more effective management in a timely fashion.

Purpose: This study aimed to determine if any cases of pulmonary arterial hypertension (PAH) were missed using routine screening of systemic sclerosis (SSc). We assessed the potential benefits of adding the DETECT algorithm and invasive hemodynamic exercise testing into the local screening process in a Danish single-center cohort without known PAH. Methods: Seventy-three patients with SSc (aged 60 ± 10 years; 56 (77%) females) underwent echocardiography. Among them, 24/73 had an elevated step 2 score of whom 3 had a high risk of pulmonary hypertension on echocardiographic assessment. Four patients declined right heart catheterization. Twenty patients (aged 62 ± 10 years, 13 (65%) females) underwent invasive hemodynamic assessment at rest. Nineteen patients participated in invasive hemodynamic exercise testing. Results: At rest, 3/20 patients met the 2022 ESC guidelines for PAH (mean pulmonary arterial pressure (mPAP) >20 mm Hg, pulmonary arterial wedge pressure (PAWP) ≤15 mm Hg, and pulmonary vascular resistance >2 Wood units). According to the 2015 ESC guidelines, only 1/19 patients had PAH. During exercise, 18/19 experienced an mPAP of >30 mm Hg, with the majority (13/19) showing an abnormal pulmonary pressure-flow relationship >3 mm Hg/liter/min. Interestingly, 7 out of 9 patients with no pulmonary hypertension (PH) at rest had exercise-induced pulmonary hypertension. One-quarter of the patients had pulmonary hypertension associated with left ventricular dysfunction (group 2 PH, WHO classification). Conclusions: In a Danish cohort of 73 patients with SSc already undergoing bi-annual PAH screening, applying the DETECT algorithm identified 3 patients meeting the 2022 ESC/ERS guideline criteria for PAH at rest, 1 of whom demonstrated increased PAWP with exercise. However, many patients exhibited an abnormal pulmonary vascular response to exercise and/or signs of group 2 PH.

The temperature distribution at the skin surface could be a useful tool to monitor changes in cardiac output. Goal: The aim of this study was to explore infrared thermography as a method to analyze temperature profiles of critically ill children. Methods: Patients admitted to the pediatric intensive care unit (PICU) were included in this study. An infrared sensor was used to take images in clinical conditions. The infrared core and limb temperatures (θc & θl) were extracted, as well as temperatures along a line drawn between these two regions. Results: The median [interquartile range] θc extracted from the images was 33.88°C [32.74-34.19] and the median θl was 30.21°C [28.89-33.13]. There was a good correlation between the θc and the clinical axillary temperature (rho = 0.39, p-value = 0.016). There was also a good correlation between the θc and θl (rho = 0.66, p-value = 1.2 e−05). Conclusion: Thermography was found to be effective to estimate the body temperature. Correlation with specific clinical conditions needs further study.

Objective: Rupture of cerebral aneurysms has a poor prognosis, and growing aneurysms are prone to rupture. Although the number of coil embolization procedures is increasing worldwide, they are more prone to recurrence than clipping surgeries. However, there is still no drug that prevents aneurysm growth or recanalization after coil embolization. The authors have previously focused on the role of hemodynamics in cerebral aneurysm development and reported that inhibition of the P2X4 purinoceptor, by which vascular endothelial cells sense blood flow, reduced the induction and growth of aneurysms in an animal model. In this study, the authors investigated the effects of paroxetine, a P2X4 inhibitor also used as an antidepressant, on aneurysm growth and recanalization after endovascular coiling., Methods: Using the J-ASPECT Study registry, the largest comprehensive reimbursement database system for acute stroke inpatient care in Japan, the authors searched for patients incidentally taking paroxetine who were registered in the decade 2010-2019 with an unruptured cerebral aneurysm or who underwent aneurysm coiling. They calculated the growth incidence and growth rate by the person-year method and the odds ratio for recanalization within 1 year after coiling and statistically compared to controls., Results: Seventy-eight stroke facilities participated, and 275 patients were identified as potentially eligible. Thirty-seven patients with unruptured aneurysms and 38 after coil embolization met all eligibility criteria. They were compared with 396 control cases of unruptured aneurysms and 308 coil-placement controls. Multivariate analysis showed that paroxetine significantly reduced the incidence of aneurysm growth (number of cases with growth/person/year; incidence rate ratio [IRR] 0.24, 95% CI 0.05-0.66; p = 0.003) and the growth rate (total increase in maximum diameter in millimeters/person/year; IRR 0.57, 95% CI 0.28-0.98; p = 0.04). Paroxetine also significantly reduced the odds of recanalization in the year after coiling (OR 0.21, 95% CI 0.05-0.95; p = 0.04). The authors then performed propensity score matching to reduce bias due to imbalances in patient characteristics between the two groups; the outcome confirmed that paroxetine significantly reduced aneurysm growth incidence (IRR 0.02, 95% CI 0.008-0.05; p < 0.0001) and growth rate (IRR 0.03, 95% CI 0.01-0.06; p < 0.0001) and the 1-year recanalization (OR 0.18, 95% CI 0.03-0.99; p = 0.04)., Conclusions: This observational cohort study suggests that P2X4 inhibitors such as paroxetine may be clinically applicable as prophylaxis against aneurysm rupture and postoperative recanalization.

Background: In general, venous aneurysm associated with dural arteriovenous fistula (dAVF) is considered to be developed under long standing venous hypertension and manifested as venous ectasia of draining vein itself. However, discrete saccular shaped venous aneurysm without angiographic evidence of venous hypertension arising from the draining vein, like cerebral arterial aneurysm, is quite rare and its pathomechanism remains unclear in patients with dAVF., Case Summary: In this report, we present two cases of ruptured saccular venous aneurysms associated with dAVF without venous hypertension or venous ectasia. In both cases, significant curve or stenosis is observed in draining vein, which is located in just distal portion of the venous aneurysms. These aneurysms were successfully treated with a transarterial embolization. Underlying mechanism of venous aneurysms in these cases is discussed., Conclusion: Although there is little doubt that hemodynamic stress has a critical role in the development of venous aneurysms in patients with dAVF, preceding venous hypertension or venous ectasia is not necessary for development and enlargement of venous aneurysms. Considering the significant risk of rupture, a careful review of draining vein features including tortuosity or stenosis is needed, especially in venous aneurysms without evidence of venous hypertension., Competing Interests: Conflict-of-interest statement: There is no conflict-of-interest to declare., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background and Purpose Previous studies have assessed the relationship between cerebral vessel tortuosity and intracranial aneurysm (IA) based on two-dimensional brain image analysis. We evaluated the relationship between cerebral vessel tortuosity and IA according to the hemodynamic location using three-dimensional (3D) analysis and studied the effect of tortuosity on the recurrence of treated IA. Methods We collected clinical and imaging data from patients with IA and disease-free controls. IAs were categorized into outer curvature and bifurcation types. Computerized analysis of the images provided information on the length of the arterial segment and tortuosity of the cerebral arteries in 3D space. Results Data from 95 patients with IA and 95 controls were analyzed. Regarding parent vessel tortuosity index (TI; P

Differentiation of mesenchymal stem cells (MSCs) into vascular endothelial cells has been demonstrated for application in cardiovascular regenerative medicine. In this study, we evaluated the effect of the combined mechanical stimuli of wall shear stress (SS) and cyclic strain (CS), mimicking hemodynamic conditions of arteries, on endothelial differentiation of MSCs. Immortalized human adipose-derived MSCs were subjected to a combined stimulations of SS (1 Pa) and CS (4%, 1 Hz) by using a developed cell culture chamber. Endothelial differentiation of MSCs was evaluated by immunofluorescent staining of an endothelial protein maker, fetal liver kinase-1 (Flk-1). Morphological changes in MSCs by the stimulation were also examined from the fluorescent images. As a result, the application of the combined stimulation of SS and CS for 24 h induced an increased expression of Flk-1 in MSCs and cell alignment to the direction of flow, whereas the stimulation of only SS or CS did not change Flk-1 expression and morphology of MSCs compared to statically cultured cells. We also found that inhibition of the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) blocked the increased expression of Flk-1 under the combined mechanical condition. These results indicate that the combination of SS and CS effectively induces MSCs differentiation into endothelial cells via activation of ERK1/2 signaling pathway.

Backgroud: Heart responds to physiologic and pathologic conditions and sympathetic drive plays an important role. It has been documented that LV base is more dominantly affected by sympathetic drive compared to the other regions. LV base is more dominantly exposed to wall stress in the initial period of remodeling due to pressure-overload, since LV cavity is the largest at base. Basal septal hypertrophy (BSH) in cross-sectional data is associated with the early phase of hypertensive heart disease. BSH was confirmed by 3rd generation microscopic ultrasound in small animals. BSH as the closest location to increased afterload could be detected in variety of stress stimuli and result in a huge septal hypertrophy in advance cases possibly related to earlier exposure of hemodynamic stress to septal wall. Conclusion: Effective geometric and functional evaluation of initial remodeling due to hemodynamic stress is important according to both human and animal data. These findings possibly contribute to early recognition of adaptive phase of hypertensive remodeling and more effective management in a timely fashion.

To examine a potential association between intranidal microhemodynamics and rupture using a phase-contrast magnetic resonance angiography (PCMRA)-based flow quantification technique in arteriovenous malformations (AVMs). We retrospectively collected data on 30 consecutive patients with AVMs (23 unruptured and 7 ruptured). Based on PCMRA data, maximal (V max) and mean (V mean) intranidal velocities were calculated. Logistic regression analysis was performed to assess factors associated with previous AVM rupture. All ruptures occurred within 6 months before PCMRA. The mean nidus volume was 4.7 mL. Eleven patients (37%) had deep draining vein(s), and 6 patients (20%) had a deep-seated nidus. The mean ± standard deviation V mean and V max were 9.6 ± 2.8 cm/second and 66.7 ± 26.2 cm/second, respectively. The logistic regression analyses revealed that higher V max (P = 0.075, unit odds ratio [OR] = 1.05, 95% confidence interval [95% CI] = 1.00–1.10) was significantly associated with prior hemorrhage. The receiver-operating curve analyses demonstrated that a V mean of 10.8 cm/second (area under the curve = 0.671) and V max of 90.2 cm/second (area under the curve = 0.764) maximized the Youden Index. A V max > 90 cm/second was significantly associated with AVM rupture both in the univariate (P = 0.025, OR = 9.0, 95% CI = 1.3–61.1) and multivariate (P = 0.008, OR = 51.7, 95% CI = 2.8–968.3) analyses. Presence of faster velocities in intranidal vessels may suggest aberrant microhemodynamics and thus be associated with AVM rupture. PCMRA-based velocimetry seems to be a promising tool to predict future AVM rupture. [ABSTRACT FROM AUTHOR]

Aplastic or twiglike middle cerebral artery (Ap/T-MCA) is a rare cerebrovascular anomaly correlated to stroke. The most common characteristic of the disease is intracerebral hemorrhage. However, treatment measures that can prevent rebleeding have not yet been established. We sought to validate whether extracranial-intracranial (EC-IC) bypass is effective in preventing recurrent intracerebral hemorrhage in patients with Ap/T-MCA. Ap/T-MCA was defined on the basis of the following criteria: 1) M1 occlusion with plexiform vessels, 2) unilateral MCA involvement without progression to the contralateral side, 3) no significant stenosis in the M2 segment, and 4) no stenoocclusive lesions in other intracranial major arteries. The clinical features, surgical procedures, radiologic changes, and treatment outcomes of patients with Ap/T-MCA who presented with ipsilateral intracerebral hemorrhage at our institution from April 2004 to December 2019 were retrospectively reviewed. Seven patients fulfilled the criteria for hemorrhagic Ap/T-MCA. Female preponderance was observed, and the mean age at the time of onset was 38 (range: 28–47) years. Three patients presented with pure intraventricular hemorrhage and 4 with intraparenchymal hemorrhage. Of the 4 patients, 2 had intraventricular extension. All patients underwent EC-IC bypass and did not present with stroke during the follow-up period (median: 36 [range: 5–140] months). Follow-up magnetic resonance imaging revealed regression of the twiglike vessels or periventricular choroidal anastomosis within 1 year after surgery in all patients. EC-IC bypass may be a treatment option that can prevent rebleeding in patients with hemorrhagic Ap/T-MCA. [ABSTRACT FROM AUTHOR]

BackgroundBlood flow restriction (BFR) training is becoming a popular form of exercise. Walking exercise in combination with pressurized wide-rigid (WR) cuffs elicits higher cardiac workload and a vascular dysfunction due presumably to reperfusion injury to the endothelium. In contrast, narrow-elastic (NE) BFR bands may elicit different hemodynamic effects. Therefore, we compared the acute cardiovascular responses to two distinct forms of BFR training during light-intensity exercise.Methods and Results15 young healthy participants (M = 9, F = 6) performed five bouts of 2-min walking intervals at 0.9 m/s with a 1-min rest and deflation period with either WR, NE, or no bands placed on upper thighs. Cuff pressure was inflated to 160 mmHg in WR cuffs and 300 mmHg in NE bands while no cuffs were used for the control. Increases in heart rate and arterial blood pressure were greater (p < 0.05) in the WR than the NE and control conditions. Double product increased to a greater extent in the WR than in the NE and control conditions. Increases in perceived exertion and blood lactate concentration were greater (p < 0.05) in the WR compared with the NE and control conditions (p < 0.05), while no differences emerged between the NE and control conditions. There were no changes in arterial stiffness or brachial artery flow-mediated dilation (FMD) after all three trials.ConclusionUse of WR BFR cuffs resulted in a marked increase in blood pressure and myocardial oxygen demand compared with NE BFR bands, suggesting that NE bands present a safer alternative for at-risk populations to perform BFR exercise.Clinical Trial RegistrationThis study was registered in the Clinicaltrials.gov (NCT03540147).

A substantial number of chronic thromboembolic pulmonary hypertension (CTEPH) patients experience dyspnea on exertion and limited exercise capacity despite surgically successful pulmonary endarterectomy (PEA). We sought to prospectively evaluate resting and peak exercise hemodynamics before, 3 and 12 months after PEA in consecutive CTEPH-patients and correlate it to physical functional capacity. Twenty consecutive CTEPH-patients were examined. Twelve months after PEA, 75% of patients with severely increased pre-PEA mean pulmonary arterial pressure (mPAP) at rest had normal or mildly increased mPAP. However, mPAP reduction was less pronounced during exercise where only 45% had normal or mildly increased mPAP at 12 months. Hemodynamic changes during exercise were tested using the pressure-flow relationship (i.e. mPAP/cardiac output (CO) slope). The average mPAP/CO slope was 7.5 ± 4.2 mm Hg/L/min preoperatively and 3.9 ± 3.0 mm Hg/L/min at 12 months (p <.005). CO reserve (CO increase from rest to peak exercise) was increased (5.7 ± 2.9 L/min) 12 months after PEA compared with pre-PEA (2.5 ± 1.8 L/min), p <.0001. However, 12 months after PEA, the CO reserve was only 49% of that of healthy controls, p <.0001. Changes in cardiac output (∆CO), calculated as the difference between CO before PEA and 12 months later, were significantly correlated with six-minute-walk-test and peak oxygen uptake (VO2), both at rest and peak exercise. Invasive exercise hemodynamic examination in CTEPH-patients demonstrates that after otherwise successful PEA surgery, >50% of patients have a significant increase in exercise mPAP, and the CO reserve remains compromised 12 months after PEA. Improvement in physical capacity is correlated with ∆CO. • True PH severity is unmasked with exercise in CTEPH patients after successful PEA. • CO reserve remains compromised in CTEPH patients at 12 months post-PEA follow-up. • Improvement in physical capacity correlated with changes in CO, but not mPAP and PVR. [ABSTRACT FROM AUTHOR]

Middle cerebral aneurysms constitute almost one-third of all anterior circulation aneurysms. Most of the saccular aneurysms originate from the arterial branching sites, but origins other than at the branching site are extremely rare. In this article, we are describing a unique M1 segment middle cerebral artery aneurysm which is not related with any branching site. Our literature search suggests that atherosclerotic changes in the arterial wall and local hemodynamic forces play an important role in the development of these types of aneurysm. Surgical management is not so unique in this type of aneurysm, but due to atherosclerotic parent arterial wall and thin-walled aneurysm sac, a neurosurgeon should be more cautious. [ABSTRACT FROM AUTHOR]

Background: Blood flow restriction (BFR) training is becoming a popular form of exercise. Walking exercise in combination with pressurized wide-rigid (WR) cuffs elicits higher cardiac workload and a vascular dysfunction due presumably to reperfusion injury to the endothelium. In contrast, narrow-elastic (NE) BFR bands may elicit different hemodynamic effects. Therefore, we compared the acute cardiovascular responses to two distinct forms of BFR training during light-intensity exercise. Methods and Results: 15 young healthy participants (M = 9, F = 6) performed five bouts of 2-min walking intervals at 0.9 m/s with a 1-min rest and deflation period with either WR, NE, or no bands placed on upper thighs. Cuff pressure was inflated to 160 mmHg in WR cuffs and 300 mmHg in NE bands while no cuffs were used for the control. Increases in heart rate and arterial blood pressure were greater (p < 0.05) in the WR than the NE and control conditions. Double product increased to a greater extent in the WR than in the NE and control conditions. Increases in perceived exertion and blood lactate concentration were greater (p < 0.05) in the WR compared with the NE and control conditions (p < 0.05), while no differences emerged between the NE and control conditions. There were no changes in arterial stiffness or brachial artery flow-mediated dilation (FMD) after all three trials. Conclusion: Use of WR BFR cuffs resulted in a marked increase in blood pressure and myocardial oxygen demand compared with NE BFR bands, suggesting that NE bands present a safer alternative for at-risk populations to perform BFR exercise. Clinical Trial Registration: This study was registered in the Clinicaltrials.gov (NCT03540147). [ABSTRACT FROM AUTHOR]

Blood flow regulation in pancreatic islets is critical for function but poorly understood. Here, we establish an in vivo imaging platform in a non-human primate where islets transplanted autologously into the anterior chamber of the eye are monitored non-invasively and longitudinally at single-cell resolution. Engrafted islets were vascularized and innervated and maintained the cytoarchitecture of in situ islets in the pancreas. Blood flow velocity in the engrafted islets was not affected by increasing blood glucose levels and/or the GLP-1R agonist liraglutide. However, islet blood flow was dynamic in nature and fluctuated in various capillaries. This was associated with vasoconstriction events resembling a sphincter-like action, most likely regulated by adrenergic signaling. These observations suggest a mechanism in primate islets that diverts blood flow to cell regions with higher metabolic demand. The described imaging technology applied in non-human primate islets may contribute to a better understanding of human islet pathophysiology.

A peripheral cerebral aneurysm is known to develop at collateral vessels as a result of hemodynamic stress by the occlusion of the intracranial major arteries. We report a case of successful embolization of a ruptured aneurysm through a transdural anastomotic artery. The aneurysm formed at the developed collateral vessel from the meningeal branch of the occipital artery (OA) to the posterior pericallosal artery. A 59-year-old man presented with acute-onset headache, and computed tomography revealed subarachnoid hemorrhage and intracerebral hemorrhage at the splenium of the corpus callosum with intraventricular hemorrhage. Digital subtraction angiography demonstrated a ruptured aneurysm located at a transdural anastomotic artery from the right OA to the posterior pericallosal artery. The patient underwent endovascular treatment for the aneurysm through the transdural anastomotic artery with a coil and n-butyl-2-cyanoacrylate. Because it was impossible to navigate a microcatheter to the aneurysm through the right anterior cerebral artery because of the occlusion of its proximal portion, it was advanced through the transdural anastomosis from the right OA. The aneurysm was completely occluded without complications. Endovascular embolization is a useful treatment option for a peripheral cerebral aneurysm developed at a collateral vessel with intracranial major artery occlusion. [ABSTRACT FROM AUTHOR]

Objective To investigate hemodynamic stresses on anterior cerebral artery bifurcation apex and possible mechanism of the optimality principle in protecting bifurcation wall from supercharged hemodynamic stresses. Methods Three-dimensional angiographic datasets of 122 patients with anterior communicating artery (Acom) aneurysms, 21 patients with non-Acom aneurysms, and 220 control subjects with no aneurysms were used. Radii of parent (r 0) and daughter branches (r 1 and r 2) were measured, and bifurcations obeying the optimality principle required optimal caliber control of r 0 n = r 1 n + r 2 n, with the junction exponent n approximating 3. Radius ratio = r 0 3/(r 1 3 + r 2 3) and n were compared between aneurysmal and control bifurcations. Blood flow was simulated for analysis of hemodynamic stresses. Results Acom bifurcations in subjects without Acom aneurysms displayed optimal caliber radius, with mean radius ratio of 0.99 and n of 3.25, whereas Acom aneurysmal bifurcations had significantly lower radius ratio, 0.62 (P < 0.05), but higher n, 4.23 (P < 0.05). Peak wall shear stress and corresponding total pressure were significantly smaller for bifurcations obeying than disobeying the optimality principle (P < 0.001 and P < 0.05, respectively). Total pressures in the direct impinging center, peak wall shear stress distance, and anterior cerebral artery bifurcation angle all were significantly smaller for bifurcations obeying than disobeying the optimality principle (P < 0.05 and P < 0.001, respectively). Conclusions Normal anterior cerebral artery bifurcations obey the optimality principle whereas bifurcations with Acom aneurysms do not. Disobeying the optimality principle presents significantly enhanced hemodynamic stresses to possibly damage the bifurcation wall for aneurysm initiation. Highlights • The optimality principle decreases hemodynamic stresses for aneurysm initiation at bifurcations. • Normal ACA bifurcations obey the optimality principle. • The ACA bifurcation with aneurysms does not obey the optimality principle. [ABSTRACT FROM AUTHOR]

Background Internal carotid artery (ICA) occlusion associated with posterior cerebral artery (PCA) aneurysms is regarded as a rare cerebrovascular disease. Common treatment of aneurysms—direct clipping or coiling—is not taken into consideration for this kind of cerebrovascular property. Combined surgical cerebrovascular reconstruction of the superficial temporal artery−to−middle cerebral artery (STA-MCA) bypass offers a chance to downregulate the hemodynamic stress of aneurysm rupture. Case Description A 46-year-old female presented with a fever and headache 1 month ago. An axial computed tomography scan showed a subarachnoid hemorrhage (SAH). Digital subtraction angiography (DSA) was conducted, and the patient received an STA-MCA bypass following medical treatment for 1 month in the local hospital. Computed tomography angiography and DSA demonstrated an aneurysm located on the right PCA and an occlusion of the right ICA in our hospital. Three days after admission, the right STA-MCA bypass was performed. The patient suffered no neurologic deterioration and lived a normal life. 6 months after the STA-MCA bypass, DSA of the right vertebral artery revealed disappearance of the aneurysm located on the right PCA (P2 segment). Conclusions Owing to ICA occlusion, the gap of hemodynamic stress between the posterior segment of the circle of Willis and anterior segment of the circle of Willis enlarged. This may lead to a ruptured PCA aneurysm. In this case, the aneurysm disappeared following an STA-MCA bypass. STA-MCA bypass may be one of the major reasons downregulating the gap, which can be regarded as an effective option concerning such aneurysms. [ABSTRACT FROM AUTHOR]

Résumé La responsabilité de l’effort dans la survenue des accidents cardiaques est connue depuis l’antiquité, on en parlait déjà au Marathon d’Athènes en 492 avant JC. L’infarctus du myocarde à l’effort représente environ 4 % des infarctus du myocarde. Il est plus fréquent chez l’homme et les jeunes patients. Il survient généralement lors des efforts intenses et surtout chez les patients non entraînés porteurs de multiples facteurs de risque. Il serait plus grave avec plus fréquemment d’onde Q de nécrose sur les électrocardiogrammes des victimes, une élévation plus importante de la troponine et un score GRACE plus avancé. La rupture de la plaque d’athérome en est la cause essentielle, elle est à l’origine de la formation du thrombus qui occlut l’artère coronaire responsable de l’infarctus du myocarde. Les contraintes hémodynamiques à l’effort imposées aux artères coronaires souvent athéromateuses favorisent la rupture et la survenue d’infarctus du myocarde lors des efforts intenses. À ces contraintes hémodynamiques lors de l’effort s’ajoutent des modifications biochimiques et rhéologiques qui favorisent la formation du thrombus intracoronaire. La survenue d’accidents coronariens aigus lors de l’effort intense, chez des patients souvent non entraînés ne doit pas nous faire oublier l’effet bénéfique de l’exercice physique sur la qualité de vie et sur la baisse de la morbi-mortalité. Heavy exertion as a trigger of cardiac events has been known since antiquity as it was already described in 492 BC in the famous Athens Marathon. Myocardial infarction occurring after physical exertion accounts for about 4% of myocardial infarctions. It is more common in men and younger patients. It usually occurs during intense efforts and especially in inactive people with multiple risk factors. It would be more severe with more frequent Q waves of necrosis on the victims’ electrocardiograms, with greater troponin release and a more raised GRACE score. Atherosclerotic plaque rupture is at the center of its pathophysiology, this event is responsible of a thrombus formation occluding the coronary artery. The hemodynamic stress imposed on the often-atheromatous coronary arteries during exercise, favor the plaque rupture and the occurrence of myocardial infarctions. To these hemodynamic constraints, are added biochemical and rheological modifications, which favor the formation of an intra-coronary thrombus. The occurrence of acute coronary events during heavy exertion in patients who are often untrained must not make us forget about the benefit of regular exercise on both the life quality and morbimortality levels. [ABSTRACT FROM AUTHOR]

Distal peripheral artery aneurysms in moyamoya disease (MMD) remain difficult to treat given their deep location, small size, and fragility. Here, we report two cases of choroidal artery aneurysms associated with MMD who were treated through direct clipping and coil embolization. Timing of aneurysm formation remains unclear, however, annual follow-up DSA for surveillance of hemodynamic status is necessary and prompt treatment of aneurysm should be performed when diagnosed. Moreover, choroidal artery aneurysms may benefit from endovascular coil embolization due to their characteristics. [ABSTRACT FROM AUTHOR]

Summary Blood flow regulation in pancreatic islets is critical for function but poorly understood. Here, we establish an in vivo imaging platform in a non-human primate where islets transplanted autologously into the anterior chamber of the eye are monitored non-invasively and longitudinally at single-cell resolution. Engrafted islets were vascularized and innervated and maintained the cytoarchitecture of in situ islets in the pancreas. Blood flow velocity in the engrafted islets was not affected by increasing blood glucose levels and/or the GLP-1R agonist liraglutide. However, islet blood flow was dynamic in nature and fluctuated in various capillaries. This was associated with vasoconstriction events resembling a sphincter-like action, most likely regulated by adrenergic signaling. These observations suggest a mechanism in primate islets that diverts blood flow to cell regions with higher metabolic demand. The described imaging technology applied in non-human primate islets may contribute to a better understanding of human islet pathophysiology. [ABSTRACT FROM AUTHOR]

We present the case of a de novo vertebral artery dissecting aneurysm (VADA) after endovascular trapping of a ruptured VADA on the contralateral side. The first ruptured VADA involved the posterior inferior cerebellar artery, which was successfully treated by endovascular internal trapping using a stent. A follow-up study at 3 months revealed a de novo VADA on the contralateral side. The second VADA was successfully embolized using coils while normal arterial flow in the vertebral artery was preserved using a stent. Increased hemodynamic stress may cause the development of a de novo VADA on the contralateral side. [ABSTRACT FROM AUTHOR]

Bicuspid aortic valves (BAVs) generate flow abnormalities that may promote aortopathy. While positive helix fraction (PHF) index, flow angle ( θ ), flow displacement ( d ) and wall shear stress (WSS) exhibit abnormalities in dilated BAV aortas, it is unclear whether those anomalies stem from the abnormal valve anatomy or the dilated aorta. Therefore, the objective of this study was to quantify the early impact of different BAV morphotypes on aorta hemodynamics prior to dilation. Fluid-structure interaction models were designed to quantify standard peak-systolic flow metrics and temporal WSS characteristics in a realistic non-dilated aorta connected to functional tricuspid aortic valve (TAV) and type-I BAVs. While BAVs generated increased helicity (PHF>0.68) in the middle ascending aorta (AA), larger systolic flow skewness ( θ >11.2°) and displacement ( d >6.8 mm) relative to the TAV (PHF=0.51; θ <5.5°; d <3.3 mm), no distinct pattern was observed between morphotypes. In contrast, WSS magnitude and directionality abnormalities were BAV morphotype- and site-dependent. Type-I BAVs subjected the AA convexity to peak-systolic WSS overloads (up to 1014% difference vs. TAV). While all BAVs increased WSS unidirectionality on the proximal AA relative to the TAV, the most significant abnormality was achieved by the BAV with left-right-coronary cusp fusion on the wall convexity (up to 0.26 decrease in oscillatory shear index vs. TAV). The results indicate the existence of strong hemodynamic abnormalities in non-dilated type-I BAV AAs, their colocalization with sites vulnerable to dilation and the superior specificity of WSS metrics over global hemodynamic metrics to the valve anatomy. [ABSTRACT FROM AUTHOR]

Background Dilatation of left atrium (LA) reflects chronic LA pressure or volume overload that possesses considerable prognostic information. Little is known regarding the interaction between LA remodeling after acute myocardial infarction (MI) and left atrial pressure at rest and during exercise. The objective was to assess changes in LA volume early after MI in patients with diastolic dysfunction and the relation to invasive hemodynamics and natriuretic peptides. Methods 62 patients with left ventricle ejection fraction (LVEF) ≥ 45%, diastolic E/e' > 8 and LA volume index > 34 ml/m 2 within 48 h of MI were enrolled. After 1 and 4 months blood sampling, echocardiography and right heart catheterization were performed during exercise test. Results LA remodeling was considered in patients with a change from mild (35–41 ml/m 2 ), to severe (> 48 ml/m 2 ) dilatation after 4 months (Found in 22 patients (35%)). Patients with LA remodeling were characterized by lower a' (1 month 8.9 ± 2.0 vs. 10.4 ± 2.5 cm/s, p = 0.002; 4 month 8.8 ± 2.0 vs. 10.4 ± 2.4 cm/s, p = 0.007) and higher MR-proANP (1 month 162 ± 64 vs. 120 ± 44 pg/l, p = 0.005; 4 months 175 ± 48 vs. 129 ± 56 pg/l, p = 0.002). With exercise, pulmonary artery pressure, right atrial pressure and pulmonary capillary wedge pressure increased markedly in all patients. There were however, no significant differences in filling pressure at rest or during exercise irrespective of whether LA remodeling occurred. Conclusion Contrary to our hypothesis early LA dilatation after MI was weakly associated with resting and exercise induced changes in LA pressure overload. The dilatation was however associated with lower e' and higher MR-proANP. [ABSTRACT FROM AUTHOR]

Chronic thromboembolic pulmonary hypertension (CTEPH) is a hot topic in the field of pulmonary hypertension because many CTEPH patients are now curable by surgical pulmonary endarterectomy. However, there are still uncertainties regarding the pathogenesis of CTEPH, specifically how and where the small vessel arteriopathy that is indistinguishable from that in pulmonary arterial hypertension (plexogenic arteriopathy) develops and how pulmonary endarterectomy improves hemodynamics and possibly cures CTEPH. Based on our recent experimental finding that hemodynamic stress is fundamental for the development of plexogenic arteriopathy, we discuss the uncertainties of CTEPH and potential implication of the effectiveness of pulmonary endarterectomy for reversing plexogenic arteriopathy and possibly providing a novel approach to cure pulmonary arterial hypertension. [ABSTRACT FROM AUTHOR]

The mammalian heart contains a population of resident macrophages that expands in response to myocardial infarction and hemodynamic stress. This expansion occurs likely through both local macrophage proliferation and monocyte recruitment. Given the role of macrophages in tissue remodeling, their contribution to adaptive processes in the heart is conceivable but currently poorly understood. In this review, we discuss monocyte and macrophage heterogeneity associated with cardiac stress, the cell's potential contribution to the pathogenesis of cardiac fibrosis, and describe different tools to study and characterize these innate immune cells. Finally, we highlight their potential role as therapeutic targets. [ABSTRACT FROM AUTHOR]

Background: A distal posterior inferior cerebellar artery (PICA) de novo aneurysm at the cortical segment after atherosclerotic basilar artery occlusion is extremely rare. Here, we report the case of a ruptured distal PICA de novo aneurysm 8 years after basilar artery occlusion. Case Description: A 75-year-old man experienced sudden disturbance of consciousness; computed tomography demonstrated cerebellar and subarachnoid hemorrhage due to a ruptured distal PICA aneurysm. Neck clipping of the aneurysm prevented re-rupture initially, and superficial temporal artery-superior cerebellar artery (STA-SCA) bypass was performed 3 months after admission. Postoperative angiography confirmed patency of the bypass, and the patient was discharged without any new neurological deficits. Conclusion: This report describes a case of de novo development of a saccular distal PICA aneurysm after atherosclerotic basilar artery occlusion. We believe that increased hemodynamic stress at the PICA might have contributed to the occurrence and rupture of the aneurysm. STA-SCA bypass, introduced in the territory of the cerebellar hemisphere, reduces hemodynamic stress, which would prevent the occurrence of de novo aneurysm and recurrent bleeding. [ABSTRACT FROM AUTHOR]

Abstracts of the oral and poster presentations and video festivals presented at the 26th World Congress of the International Association of Surgeons, Gastroenterologists and oncologists (IASGO) that will be held on September 8-10, 2016 in Seoul, South Korea are presented.