Arterial Circulation Research Articles

Implementation to cardiovascular disorders under the action of magnetohydrodynamics in a non‐Newtonian peristaltic blood flow of nanofluid

AbstractThe issue of vascular stenosis has recently received significant innovative interest among researchers. Due to the buildup of adipocytes and other constituents of atherosclerotic, arteries can generate an abnormal condition called arterial stenosis. It optimizes blood circulation to prevent myocardial illness. In light of this, the current scientific report assembled a Casson fluid model to assess the MHD peristaltic transit of blood supply via a mildly stenotic artery when copper nanoparticles are added. A relevant simulation model is often used to outline the issue, acquiring non‐dimensional variables and approximations for the stenosis. Temperature has quantitative approaches, and the result for velocity is derived numerically in MATHEMATICA. The expressions for Nusselt number, wall shear stress, flow resistance distribution and stream function are attained. The under action of copper nanoparticles, the consequences of several new physiological measures on arterial blood circulation properties are visually displayed and explained briefly. A pictorial explanation of the trapping phenomena is also provided. In comparison to arteries devoid of stenosis, arteries with stenosis have a higher temperature distribution throughout the fluid flow and velocity. In addition, high temperature and velocity increase in the middle of the artery and decrease as one gets closer to the arterial wall. Further, the concentration, Grashof number and heat source and sink parameters of the nanoparticles reduce the wall shear stress of the blood in the arteries since the arterial wall contributes heat to the flow zone. The discovery could have medical applications as well as bioinformatics. Furthermore, the current work contributes to the cure of different cardiac illnesses.

Endovascular treatment of post-thrombotic syndrome of the lower extremities caused by combat trauma. Clinical case

In the course of Russia’s military invasion of Ukraine, gunshot shrapnel wounds of the lower extremities that result in damage to major blood vessels have become a common phenomenon. Their incidence is consistent with the general data on combat‑related vascular injuries. Vascular gunshot injuries can cause significant changes to the normal anatomy and hemodynamics of the extremity as a result of the bullet or shrapnel travelling through the wound channel. Combat trauma of the vascular bundle, either as a primary factor or in combination with other lesions, often causes a serious condition in the wounded that requires urgent surgical intervention]. Injury to the major blood vessels of the lower limbs carries the risk of critical ischemia, which can lead to higher mortality rates, poor limb recovery, and disability. This clinical case demonstrates the endovascular management of a disabling combat‑related vascular injury. The treatment involves the use of modern imaging techniques and minimally invasive surgical procedures. This case highlights the progression of the pathological process after a gunshot shrapnel wound to the soft tissues and major blood vessels. It also shows a change in the normal anatomy of the major blood vessels and the subsequent development of regional hemodynamic disorders of the lower limb after injury. In January 2023, a 51‑year‑old male received a gunshot wound to the soft tissues of the pelvis and right lower limb, as well as a gunshot fracture of the right femur. Immediate post‑evacuation therapy included the management of life‑threatening bleeding by ligating the deep femoral artery and providing external fixation of the gunshot femur fracture. Following the healing of the wounds and the removal of the external fixation device, the injured individual experienced a progressive and notable swelling of the lower limb over a period of 3 months. Subsequently, trophic ulcers appeared on the lower leg. In September 2023, the patient was admitted to the National Military Medical Clinical Centre in Kyiv after developing clinical signs of the post‑thrombotic syndrome. However, further examination revealed the presence of an AV fistula. Consequently, a simultaneous endovascular reconstructive intervention was performed on the arteries and veins of the patient’s lower extremity. Conclusions. A gunshot wound to the major blood vessels can contribute to pathological changes in the normal anatomical structure, resulting in arterial collateral blood circulation or narrowing of blood vessels that can lead to regional hemodynamic disorders. The clinical case exemplifies the importance of using modern imaging techniques for a comprehensive examination of the vascular system and the possibility of minimally invasive treatment for patients with gunshot injuries to the major blood vessels.

The Importance of the Circle of Willis in Carotid Interventions Outcomes: A Real-Life Study

ObjectiveThe main objective of this study is to evaluate and compare the outcomes regarding operative mortality rate, ipsilateral stroke and overall survival rate among patients with internal carotid artery (ICA) stenosis submitted to carotid endarterectomy or stenting regarding the completeness of Circle of Willis (CoW). MethodsProspective, consecutive cohort study of patients submitted to carotid interventions (carotid endarterectomy – CEA - and carotid stenting - CAS) for ICA stenosis diagnosis evaluated according complete or incomplete CoW. The patients were divided into two groups: group I - the patients with complete CoW and group II - the patients with incomplete CoW, with the disruption of anterior and/ or ipsilateral posterior circulation, regarding the ipsilateral significant carotid stenosis. ResultsOverall, 98 patients submitted to carotid intervention were evaluated. Two groups of patients were identified: group CoW complete with 54 patients and group CoW incomplete with 44 patients. Regarding the type of intervention, the prevalence of CAS in CoW complete group and CoW incomplete group were statistically similar (54.1% versus 55.1%, p = 0.22). Notwithstanding, CEA was also statistically similar in CoW incomplete group and CoW complete group (44.2% versus 45.9%, p = 0.22). The perioperative mortality rate was 2% in total cohort (2 patients), with no differences among CoW complete and incomplete groups (3.7% versus 0%, p = 0.50, respectively). Furthermore, the incidence of post-operative stroke was 3.1% (asymptomatic 2%, symptomatic 1.1%), with no differences among CoW complete and incomplete groups (3.7% versus 2.3%, p = 0.68, respectively). A univariate and multivariate linear regression showed that among the factors evaluated, only chronic kidney failure was related with HR = 1.89, p = 0.003, CI 1.058-2.850. ConclusionThe completeness of the CoW, independently of the type of carotid intervention (CEA and CAS), did not interfere in the results regarding postoperative outcomes for stroke and death. Chronic Kidney disease was associated to increased risk of perioperative stroke.

Factors associated with thrombotic disease in dogs with renal proteinuria: A retrospective of 150 cases.

Knowledge of additional risk factors for thrombotic disease (TD) among dogs with renal proteinuria is limited; these might differ for TD affecting the systemic arterial (AT), systemic venous (VT), and pulmonary circulation (PT). To compare signalment and clinicopathological data between dogs with renal proteinuria with or without TD, and between dogs with AT, VT, and PT. One hundred fifty client-owned dogs with renal proteinuria, 50 of which had TD. Retrospective case-controlled study. A database search (2004-2021) identified proteinuric dogs (UPC > 2) with and without TD. Clinicopathological data were obtained from the records. TD and non-TD (NTD) groups were compared by binary logistic regression, and AT, VT, and PT groups by multinomial regression. Normal data presented as mean ± SD, non-normal data presented as median [25th, 75th percentiles]. Cavalier King Charles Spaniels were overrepresented in the TD group (OR = 98.8, 95% CI 2.09-4671, P = .02). Compared to NTD cases, TD cases had higher concentration of neutrophils (11.06 [8.92, 16.58] × 109 /L vs 7.31 [5.63, 11.06] × 109 /L, P = .02), and lower concentration of eosinophils (0 [0, 0.21] × 109 /L vs 0.17 [0.04, 0.41] × 109 /L, P = .002) in blood, and lower serum albumin (2.45 ± 0.73 g/dL vs 2.83 ± 0.73 g/dL, P = .04). AT cases had higher serum albumin concentrations than VT cases (2.73 ± 0.48 g/dL vs 2.17 ± 0.49 g/dL, P = .03) and were older than PT cases (10.6 ± 2.6 years vs 7.0 ± 4.3 years, P = .008). VT cases were older (9.1 ± 4.2 years vs 7.0 ± 4.3 years, P = .008) and had higher serum cholesterol concentration (398 [309-692 mg/dL] vs 255 [155-402 mg/dL], P = .03) than PT cases. Differences between thrombus locations could reflect differences in pathogenesis.

Why do we keep missing left circumflex artery myocardial infarctions?

BackgroundDiagnosis of left circumflex artery (LCx) myocardial infarctions via 12‑lead electrocardiogram (ECG) has posed a challenge to healthcare professionals for many years. Methods and resultsA retrospective observational study was performed to analyze patients admitted with myocardial infarction. The study used electronic medical records and specific ICD-10 codes to identify eligible patients, resulting in 2032 encounters. After independent adjudication of cardiac biomarkers, coronary angiography, and electrocardiographic changes, a final patient population of 58 encounters with acute occlusion myocardial infarction (OMI) with a culprit LCx lesion was established. OMI was defined as a lesion with either thrombolysis in myocardial infarction flow (TIMI) 0–2 or TIMI 3 with Troponin I > 1 ng/mL (Reference range 0.00–0.03 ng/mL). ECGs of these patients were then independently evaluated and grouped into 8 different classifications based on the presence or absence of ST elevation and/or depression in corresponding leads. ECG patterns and anatomical characteristics (proximal or distal to the first obtuse marginal artery) of the LCx lesions were then correlated. The appropriateness of triage and delay in reperfusion therapy were also assessed. Those with a left dominant or codominant circulation, and with LCx lesions proximal to the first obtuse marginal artery, were more likely to present with no or subtle ST-segment changes that led to delays in reperfusion therapy. ConclusionsPatients with left or codominant coronary artery circulation, with OMI proximal to the first obtuse marginal artery, may be less likely to have “classic” findings of ST-segment elevation on ECG due to cancellation forces in the limb leads.

Arterial revascularization in patients with hand pain dialyzing with upper arm Arteriovenous (AV) fistulas: A single center experience.

Distal hand ischemia syndrome (DHIS) is a well reported adverse outcome in patients with upper arm AV access. 25%-40% of these patients have been reported to be due to primary arterial disease complicated with significant arterial calcification. The effectiveness of revascularization of the distal arterial circulation on symptom resolution has not been reported yet. Retrospective single center analysis of patients evaluated for hand/forearm pain in patients with upper arm AV access who had arterial revascularization between 01/2016 and 12/2020 were included for the analysis. Fifty-one patients met inclusion criteria. Stenotic lesions greater than 70% in the subclavian, axillary, brachial, radial, or ulnar artery were treated with balloon angioplasty. Institutional approval was obtained to review charts. Successful revascularization, improvement in pain in 48 h, 1 month, and 3 months. Seventy six percent of patients had an upper arm Arteriovenous Fistula (AVF) and 24% patients had an upper arm Arteriovenous Graft (AVG). Mean access flow was 1210 (556) ml/min. 55% of patients had radial or ulnar arterial stenosis, 45% had brachial/axillary or subclavian artery stenosis. 45% patients had lesions in both radial and ulnar arteries, 88% of patients were successfully revascularized. 76% (18) of patients had improvement in symptoms within 48 h and 68% remained symptom free in 3 months. Mean DHIS stage was 3.1 before intervention and improved to 1.1 post intervention (p < 0.001). Patient satisfaction with their AV access improved from 34% to 72% (p < 0.01). Multiple regression analysis did not reveal statistically significant correlations between time on dialysis vintage and other chronic medical conditions on post procedure symptom improvement. DHIS with occlusive arterial disease can be successfully revascularized to improve symptoms. Complete evaluation of the inflow arterial segment and optimal endovascular revascularization could decrease the need for access revision procedures or access abandonment.

Modeling of blood flow in cerebral arterial circulation and its dynamic impact on electrical conductivity in a realistic multi-compartment head model

Background and ObjectiveThis study aims to assess the dynamic impact of non-Newtonian cerebral arterial circulation on electrical conductivity within a realistic multi-compartment head model. Evaluating this research question is crucial and challenging due to its relevance to electrophysiological modalities like transcranial electrical stimulation (tES), electro-/magnetoencephalography (EEG/MEG), and electrical impedance tomography (EIT). In these modalities, accurate forward modeling depends on the electrical conductivity, which is affected by complex tortuous vessel networks, limited data acquisition in Magnetic Resonance Imaging (MRI), and non-linear blood flow phenomena, including shear rate and viscosity in non-Newtonian fluid. MethodsTo obtain an approximation for the blood concentration, we first use Navier–Stokes equations (NSEs) to solve for the pressure and velocity of the blood in the major vessels. Then Fick's law is used to solve for the blood concentration in the tissues. Finally, Archie's law is used to estimate the electrical conductivity distribution based on the blood concentration. ResultsThe results, obtained with an open 7 Tesla MRI dataset, suggest that a dynamic model of cerebral blood flow (CBF) for both arterial and microcirculation can be established; we find blood pressure and electrical conductivity distributions given a numerically simulated pulse sequence and approximate the blood concentration and electrical conductivity inside the brain based on those. ConclusionsOur model provides an approximation of the dynamical blood flow and the corresponding electrical conductivity distribution in the different parts of the brain. The advantage of our approach is that it is applicable with limited a priori information about the blood flow and with an arbitrary head model distinguishing the arteries.

Evaluating the Impact of Domain Boundaries on Hemodynamics in Intracranial Aneurysms within the Circle of Willis

Hemodynamic simulations are increasingly used to study vascular diseases such as Intracranial Aneurysms (IA) and to further develop treatment options. However, due to limited data, certain aspects must rely on heuristics, especially at the simulation’s distal ends. In the literature, Murray’s Law is often used to model the outflow split based on vessel cross-section area; however, this poses challenges for the communicating arteries in the Circle of Willis (CoW). In this study, we contribute by assessing the impact of Murray’s Law in patient-specific geometries featuring IA at the posterior communication. We simulate different domain extensions representing common modelling choices and establish Full CoW simulations as a baseline to evaluate the effect of these modelling assumptions on hemodynamic indicators, focusing on IA growth and rupture-related factors such as the Wall Shear Stress (WSS) and Oscillatory Shear Index (OSI). Our findings reveal qualitative alterations in hemodynamics when not modeling posterior communication. Comparisons between computing the anterior circulation and computing the whole Circle of Willis reveal that quantitative changes in WSS may reach up to 80%, highlighting the significance of modelling choices in assessing IA risks and treatment strategies.

Classification and treatment strategy for Moyamoya disease-related aneurysms

BackgroundMoyamoya disease (MMD) is a cerebrovascular disorder characterized by progressive unilateral or bilateral stenosis of the distal internal carotid artery. As hemodynamic features in MMD patients alter, the comorbidity of intracranial aneurysm (IA) is sometimes observed clinically. We aim to investigate clinical characteristics and therapeutic strategies for the comorbidity of Moyamoya disease with intracranial aneurysms (MMD-IA).MethodsA total of 13 MMD-IA patients were recruited in this study and were manifested to be intracranial hemorrhage. We reviewed the surgical technique notes for all patients.ResultsAccording to the locations of an aneurysm, MMD-IA could be divided into several categories: (1) MMD-IA at a circle of Willis—aneurysms usually located at the trunk of Willis circle; (2) MMD-IA at collateral anastomosis—aneurysms located at the distal end of collateral anastomosis; and (3) MMA-IA at basal ganglia region. In this report, aneurysms in 10 patients located at Willis circle, 2 at the pericallosal artery, and 1 at the basal ganglia region. Among them, endovascular embolism was performed among 5 patients. Aneurysm clipping was conducted among 7 patients. A patient with an aneurysm at the basal ganglia region just accepted revascularization treatment. All the treatments were successful. Follow-up studies, ranging from 6 to 24 months, demonstrated all patients received satisfactory curative effects.ConclusionDiverse clinical presentations could be observed among MMD-IA patients. Individualized neurosurgical treatments should be chosen according to the locations of the aneurysm.

A rare anatomical variation of the circle of Willis in a patient with an ischemic stroke

Purpose &#x0D; The cerebral arterial circuit provides collateral circulation to the brain and protects the brain from ischemia, by sustaining tissue perfusion in case of reduced or impaired blood flow through its branches. Although many random anatomical variations in the circle of Willis (CoW) are of minor importance, some increase the risk of ischemic events, aneurysm, and atherosclerosis, and play an important role in endovascular and surgical treatment planning. &#x0D; Case presentation &#x0D; We report a rare arterial variation of the CoW diagnosed by computed tomography angiography in a patient with ischemic stroke. We found aplasia of the A1 segment of the left anterior cerebral artery and ipsilateral hypoplasia of the P1 segment of the left posterior cerebral artery. &#x0D; Conclusion &#x0D; For neurosurgeons, neurologists, and neuroradiologists, detailed knowledge of the numerous anatomical variations in the arterial supply to the brain is crucial to make a correct diagnosis and choose the appropriate treatment. The type of CoW variation influences stroke severity and outcome, with an incomplete CoW related to more severe conditions (higher National Institutes of Health Stroke Scale scores, more severe neurological deficits, and worse neurological outcomes) and poor prognosis.

Rotation effect on a fluid model exhibiting thermo-diffusion in a porous environment subject to convective boundary conditions through a slanted conduit

The goal of this work is to show how important the rotation effect is by using a model that simulates thermo-diffusion in a porous material. The model incorporates convective boundary conditions and an inclined conduit to provide a comprehensive analysis. Hall current and thermal flux’s prospective repercussions are considered. We assume a long wavelength and a low Reynolds number to approximate the solution of the governing equations of motion. The current investigation has substantial significance for several medical scenarios, including the movement of gastric fluid inside the intestinal tract and blood circulation in arteries. Utilizing a peristaltic transport mechanism with minor stenosis, industries such as water purification and the production of artificial hearts and lungs have used the transport mechanism. Various physical attributes of the issue are discussed, and their graphic effects are illustrated. Increasing the porosity parameter, hall current parameter and grashof number causes the velocity distribution to enhance, whereas increasing the biot number causes it to diverge. The radiation parameter and Prandtl number improve as temperature distribution extends, whereas the biot number worsens it. The magnitudes of the skin friction coefficient and the nusselt number exhibit a positive correlation with both the Prandtl number and the radiation parameter. Moreover, the present study compares the numerical velocity values with those reported in a previously published publication.

The Arteries of the Encephalon Base in Caracal (Caracal caracal; Felidae; Carnivora).

This study represents the comprehensive anatomical analysis of the arterial circulation at the base of the encephalon in caracal (Caracal caracal), a member of the Felidae family. Caracals are found in various environments in Africa and Asia, and their conservation status is threatened by hunting and habitat loss. This study was conducted on 14 post-mortem specimens obtained from zoos. Three different methods were used to prepare the specimens-corrosive preparation, latex specimen preparation, and computer tomography imaging. This study revealed a configuration of the arterial circulation in the caracal encephalon resembling the shape of the number eight. The presence of the rostral communicating artery in this species is of particular significance, as it is associated with an increased ability to detect dehydration in the forebrain. This adaptation plays a crucial role in responding to challenges related to hydration. Comparative anatomical analysis with other felids highlighted differences in the shape and configuration of the encephalon's arterial circulation. This study also discussed the obliteration of the extracranial segment of the internal carotid artery in adult caracals, a feature shared with other Felidae members. The results of this study provide valuable information regarding the anatomy of blood vessels in caracals, with potential implications for veterinary practice in zoos and wildlife conservation efforts. This research expands our knowledge of this species' unique adaptations and physiological processes, contributing to the development of comparative anatomy in the Felidae family.

Peripheral artery disease diagnosis based on deep learning-enabled analysis of non-invasive arterial pulse waveforms

This paper intends to investigate the feasibility of peripheral artery disease (PAD) diagnosis based on the analysis of non-invasive arterial pulse waveforms. We generated realistic synthetic arterial blood pressure (BP) and pulse volume recording (PVR) waveform signals pertaining to PAD present at the abdominal aorta with a wide range of severity levels using a mathematical model that simulates arterial blood circulation and arterial BP-PVR relationships. We developed a deep learning (DL)-enabled algorithm that can diagnose PAD by analyzing brachial and tibial PVR waveforms, and evaluated its efficacy in comparison with the same DL-enabled algorithm based on brachial and tibial arterial BP waveforms as well as the ankle-brachial index (ABI). The results suggested that it is possible to detect PAD based on DL-enabled PVR waveform analysis with adequate accuracy, and its detection efficacy is close to when arterial BP is used (positive and negative predictive values at 40 % abdominal aorta occlusion: 0.78 vs 0.89 and 0.85 vs 0.94; area under the ROC curve (AUC): 0.90 vs 0.97). On the other hand, its efficacy in estimating PAD severity level is not as good as when arterial BP is used (r value: 0.77 vs 0.93; Bland-Altman limits of agreement: −32%-+32 % vs −20%-+19 %). In addition, DL-enabled PVR waveform analysis significantly outperformed ABI in both detection and severity estimation. In sum, the findings from this paper suggest the potential of DL-enabled non-invasive arterial pulse waveform analysis as an affordable and non-invasive means for PAD diagnosis.

FAUX ANEVRISMES POSTTRAUMATIQUES DE L’ARTERE FEMORALE SUPERFICIELLE : A PROPOS DE TROIS CAS OPERES

Post-traumatic superficial femoral artery pseudoaneurysm are rare. The aim of their treatment is to exclude the pseudoaneurysm from the arterial circulation while maintaining distal vascularization of the limb. That can be done by open surgical repair or by endovascular procedure. We report three cases of post-traumatic pseudoaneurysm of the superficial femoral artery operated on in our centre. The authors want to present three surgical treatment modalities for post-traumatic pseudoaneurysm, of the superficial femoral artery, namely direct suture, bypass using an inverted saphenous vein graft and ligation of the superficial femoral artery.

КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ УСПЕШНОГО СОВМЕСТНОГО ПРОВЕДЕНИЯ ТРОМБОЛИТИЧЕСКОЙ ТЕРАПИИ, МЕХАНИЧЕСКОЙ ТРОМБОЭКСТРАКЦИИ И СТЕНТИРОВАНИЯ У ПАЦИЕНТА С ИШЕМИЧЕСКИМ ИНСУЛЬТОМ В БАССЕЙНЕ ПРАВОЙ СРЕДНЕЙ МОЗГОВОЙ АРТЕРИИ

Abstract. Introduction. As of today, acute cerebrovascular accident is still the most important medical and social challenge in the modern society, due to its high growth rates of morbidity, disability, and mortality. A highly proven method of ischemic stroke treatment is reperfusion therapy, including intravenous thrombolytic therapy and mechanical thrombus extraction. Thrombus extraction is a high–tech medical procedure aimed at removing blood clots, which is the most effective way to treat patients with ischemic stroke. Aim. To illustrate the efficiency of collaborative thrombolytic therapy, mechanical thrombus extraction, and stenting. Materials and Methods. The article presents a clinical case report on a patient with ischemic stroke in the territory of the right middle cerebral artery upon the successful collaborative thrombolytic therapy, mechanical thrombus extraction, and stenting. The patient’s neurological status was assessed, and neuroimaging was performed before and after thrombolytic therapy, mechanical thrombus extraction, and stenting; laboratory tests and instrumental investigations were carried out, and secondary prevention was prescribed. Results and Discussion. Due to the successful staged reperfusion therapy including intravenous thrombolytic therapy followed by mechanical thrombus extraction using a stent retriever, and stenting of the right internal carotid artery, the physicians managed to achieve the restoration of blood flow along the right middle cerebral artery with significant clinical regression of neurological deficit, which achievement demonstrated the effectiveness, safety, and expediency of using this treatment technique. Combining these methods is efficient for the treatment of patients with ischemic stroke caused by the major artery occlusions in the anterior parts of Willis circle. In centers of vascular medicine where there is no high-tech medical care, thrombolytic therapy is administered intravenously in one medical institution, and then the patient is transferred to another one where it is possible to perform mechanical thrombus extraction, or both reperfusion therapy techniques can be used within one medical institution. Conclusions. Collaboratively performing the above procedures illustrates their high efficiency and safety. Time elapsed from the disease onset to the treatment initiation is essential to successful recanalization.

КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ УСПЕШНОГО СОВМЕСТНОГО ПРОВЕДЕНИЯ ТРОМБОЛИТИЧЕСКОЙ ТЕРАПИИ, МЕХАНИЧЕСКОЙ ТРОМБОЭКСТРАКЦИИ И СТЕНТИРОВАНИЯ У ПАЦИЕНТА С ИШЕМИЧЕСКИМ ИНСУЛЬТОМ В БАССЕЙНЕ ПРАВОЙ СРЕДНЕЙ МОЗГОВОЙ АРТЕРИИ

Abstract. Introduction. As of today, acute cerebrovascular accident is still the most important medical and social challenge in the modern society, due to its high growth rates of morbidity, disability, and mortality. A highly proven method of ischemic stroke treatment is reperfusion therapy, including intravenous thrombolytic therapy and mechanical thrombus extraction. Thrombus extraction is a high–tech medical procedure aimed at removing blood clots, which is the most effective way to treat patients with ischemic stroke. Aim. To illustrate the efficiency of collaborative thrombolytic therapy, mechanical thrombus extraction, and stenting. Materials and Methods. The article presents a clinical case report on a patient with ischemic stroke in the territory of the right middle cerebral artery upon the successful collaborative thrombolytic therapy, mechanical thrombus extraction, and stenting. The patient’s neurological status was assessed, and neuroimaging was performed before and after thrombolytic therapy, mechanical thrombus extraction, and stenting; laboratory tests and instrumental investigations were carried out, and secondary prevention was prescribed. Results and Discussion. Due to the successful staged reperfusion therapy including intravenous thrombolytic therapy followed by mechanical thrombus extraction using a stent retriever, and stenting of the right internal carotid artery, the physicians managed to achieve the restoration of blood flow along the right middle cerebral artery with significant clinical regression of neurological deficit, which achievement demonstrated the effectiveness, safety, and expediency of using this treatment technique. Combining these methods is efficient for the treatment of patients with ischemic stroke caused by the major artery occlusions in the anterior parts of Willis circle. In centers of vascular medicine where there is no high-tech medical care, thrombolytic therapy is administered intravenously in one medical institution, and then the patient is transferred to another one where it is possible to perform mechanical thrombus extraction, or both reperfusion therapy techniques can be used within one medical institution. Conclusions. Collaboratively performing the above procedures illustrates their high efficiency and safety. Time elapsed from the disease onset to the treatment initiation is essential to successful recanalization.

History of blood pressure measurement in newborns and infants.

The development of methods for measuring blood pressure (BP) in newborns and small children has a rich history. Methods for BP measuring in adults had to be adapted to this age group. For measuring BP in direct invasive way, a suitable approach had to be found to access the arterial circulation through the umbilical and later radialis artery. Currently, results obtained from direct invasive BP measurement are considered the "gold standard". The development of non-invasive methods for BP measuring in newborns and children began with the use of von Basch's sphygmomanometer (1880). In 1899, Gustav Gärtner constructed the device, which was the basis for the flush method. After the discovery of the palpation and auscultation methods, these methods were also used for BP measurement in newborns and children, however, the BP values obtained in these ways were typically underestimated using excessively wide cuffs. From the auscultation method, methods utilizing ultrasound and infrasound to detect arterial wall movement and blood flow were later developed. The oscillometric method for BP measurement was introduced by E. J. Marey so early as in 1876. In 1912, P. Balard used the oscillometric technique to measure blood pressure in a large group of newborns. Through different types of oscillometers using various methods for detecting vascular oscillations (such as xylol method, impedance and volume plethysmography, etc.), the development has continued to assessment of vascular oscillations by modern sensor technology and software. For continuous non-invasive blood pressure measurement, the volume-clamp method, first described by Jan Peňáz in 1968, was developed. After modification for use in newborns, application of the cuff to the wrist instead of the finger, it is primarily used in clinical physiological studies to evaluate beat-to-beat BP and heart rate pressure variability, such as in the determination of the baroreflex sensitivity.

Cerebral uptake of microvesicles occurs in normocapnic but not hypocapnic passive hyperthermia in young healthy male adults.

Passive hyperthermia causes cerebral hypoperfusion primarily from heat-induced respiratory alkalosis. However, despite the cerebral hypoperfusion, it is possible that the mild alkalosis might help to attenuate cerebral inflammation. In this study, the cerebral exchange of extracellular vesicles (microvesicles), which are known to elicit pro-inflammatory responses when released in conditions of stress, were examined in hyperthermia with and without respiratory alkalosis. Ten healthy male adults were heated passively, using a warm water-perfused suit, up to core temperature+2°C. Blood samples were taken from the radial artery and internal jugular bulb. Microvesicle concentrations were determined in platelet-poor plasma via cells expressing CD62E (activated endothelial cells), CD31+ /CD42b- (apoptotic endothelial cells), CD14 (monocytes) and CD45 (pan-leucocytes). Cerebral blood flow was measured via duplex ultrasound of the internal carotid and vertebral arteries to determine cerebral exchange kinetics. From baseline to poikilocapnic (alkalotic) hyperthermia, there was no change in microvesicle concentration from any cell origin measured (P-values all >0.05). However, when blood CO2 tension was normalized to baseline levels in hyperthermia, there was a marked increase in cerebral uptake of microvesicles expressing CD62E (P=0.028), CD31+ /CD42b- (P=0.003) and CD14 (P=0.031) compared with baseline, corresponding to large increases in arterial but not jugular venous concentrations. In a subset of seven participants who underwent hypercapnia and hypocapnia in the absence of heating, there was no change in microvesicle concentrations or cerebral exchange, suggesting that hyperthermia potentiated the CO2 /pH-mediated cerebral uptake of microvesicles. These data provide insight into a potential beneficial role of respiratory alkalosis in heat stress. KEY POINTS: The hyperthermia-induced hyperventilatory response is observed in most humans, despite causing potentially harmful reductions in cerebral blood flow. We tested the hypothesis that the respiratory-induced alkalosis is associated with lower circulating microvesicle concentrations, specifically in the brain, despite the reductions in blood flow. At core temperature+2°C with respiratory alkalosis, microvesicles derived from endothelial cells, monocytes and leucocytes were at concentrations similar to baseline in the arterial and cerebral venous circulation, with no changes in cross-brain microvesicle kinetics. However, when core temperature was increased by 2°C with CO2 /pH normalized to resting levels, there was a marked cerebral uptake of microvesicles derived from endothelial cells and monocytes. The CO2 /pH-mediated alteration in cerebral microvesicle uptake occurred only in hyperthermia. These new findings suggest that the heat-induced hyperventilatory response might serve a beneficial role by preventing potentially inflammatory microvesicle uptake in the brain.

COVID-19 and Long-COVID Thrombosis: From Clinical and Basic Science to Therapeutics.

Coronavirus infectious disease-19 (COVID-19) is a pandemic characterized by serious lung disease and thrombotic events in the venous and circulation trees, which represent a harmful clinical sign of poor outcome. Thrombotic events are more frequent in patients with severe disease requiring intensive care units and are associated with platelet and clotting activation. However, after resolution of acute infection, patients may still have clinical sequelae, the so-called long-COVID-19, including thrombotic events again in the venous and arterial circulation. The mechanisms accounting for thrombosis in acute and long COVID-19 have not been fully clarified; interactions of COVID-19 with angiotensin converting enzyme 2 or toll-like receptor family or infection-induced cytokine storm have been suggested to be implicated in endothelial cells, leucocytes, and platelets to elicit clotting activation in acute as well in chronic phase of the disease. In acute COVID-19, prophylactic or full doses of anticoagulants exert beneficial effects even if the dosage choice is still under investigation; however, a residual risk still remains suggesting a need for a more appropriate therapeutic approach. In long COVID-19 preliminary data provided useful information in terms of antiplatelet treatment but definition of candidates for thrombotic prophylaxis is still undefined.

Real-time model-based cerebral perfusion calculation for ischemic stroke

Background and ObjectivesClinical diagnosis of ischemic stroke commonly relies on examining cerebral perfusion changes by using computed tomography perfusion (CTP) techniques. However, the radiation dose in CTP is quite higher in comparison to computed tomography angiography (CTA), with associated costs and time. MethodsHence, this study established a lumped-parameter model (LPM) of brain tissue microcirculation (BTM) based on CTA, aiming to achieve real-time calculation of cerebral perfusion. After validation of calculated flow results with clinical data, the BTM-LPM model was used to examine the changes in cerebral perfusion following ischemic stroke, in which the effects of nine anatomical structures of the Circle of Willis (CoW) together with various distribution patterns of stenosis in the feeding arteries were considered. ResultsWhen compared the calculated flow results from BTM-LPM with the clinically measured data of literature, the mean squared error (MSE) value for the feeding arteries was 3.9 % and its total value for microcirculatory flow in each region was 0.1 %. Notably, the calculation time was 35.6 s. In the case of the CoW missing the left and right posterior communicating artery, a 60 % stenosis of the basilar artery is likely to cause ischemic damage to some temporal and occipital lobes of the right and left hemispheres. While in the case of the CoW missing the anterior communicating artery and the left posterior communicating artery, ischemic damage to the entire frontal lobe and parts of the temporal and parietal lobes of the left hemisphere was found when 80 % stenosis occurred in the left internal carotid artery. ConclusionsThe BTM-LPM proposed in this study could accurately calculate cerebral perfusion in real time and demonstrated the importance of CoW anatomy in different ischemic injuries to cerebral tissue. The calculated cerebral perfusion would be a reference value for early diagnosis and preoperative planning of different ischemic injuries to cerebral tissue, thereby the BTM-LPM holds great promising for replacing CTP examination.