Total Blood Flow Research Articles

The inability of spectral Doppler ultrasonography to identify stallions with testicular dysfunction.

This retrospective study aimed to validate the usefulness of spectral Doppler ultrasonography in diagnosing testicular dysfunction in stallions. The first part of the study included a pony stallion with age-related testicular degeneration (18 - 21 yrs. old). Testicular dimensions, spectral Doppler parameters of testicular blood flow, and semen parameters were obtained numerous times from this pony over four consecutive years. While testicular volume decreased dramatically, and the stallion became azoospermic, there were no changes in any of the spectral Doppler parameters of testicular blood flow, except the TABF rate (Total Arterial Blood Flow rate). TABF rate gradually increased, most likely due to a significant decrease in testicular volume. In the second part of the study, medical records of four horse stallions (5 - 8 yrs. old) with testicular dysfunction (TDF) were reviewed and analyzed. Parameters evaluated included testicular dimensions, spectral Doppler parameters of testicular blood flow, and semen parameters. Five fertile stallions (FR) served as the reference for TDF stallions. There were no significant differences between FR and TDF stallions in any of the spectral Doppler parameters of testicular blood flow, except TABF, which was significantly higher in FR stallions than in TDF stallions (P<0,005). This was likely caused by the larger testicular artery diameter in FR stallions. However, when individual stallions were considered, the values of the TABF overlapped between FR and TDF stallions. Based on the results of this study, we conclude that spectral Doppler ultrasonography is not always a reliable method for diagnosing testicular dysfunction in stallions.

Mechanical properties of stenosed coronary arterial walls with slip velocity

In the present manuscript, a detailed exploration of the non-Newtonian blood flow along an elastic, stenosed branched coronary artery is undertaken. The study involves the coupling of the laminar flow model with the solid mechanics model to achieve the fluid–structure interaction through the arbitrary Lagrangian–Eulerian approach. The characteristics of fluid flow, including velocity, pressure, and wall shear stress are examined in relation to the elastic properties of the arterial wall. The changes in several biomechanical parameters, such as principal strain, solid velocity, deformation gradient, Cauchy–Green stress tensor, and Von Mises stress along the intima layer, highlight areas vulnerable to endothelial dysfunction. The upper branch of the bifurcation is observed to carry only around 10% of the total blood flow, resulting in the formation of recirculation zones at the junction where oscillatory shear stress is elevated. Flow separation is noticed at the point on the junction wall opposite the stream experiencing an increased pressure of 1.79% of that of the neighborhood. The wall displacement profiles indicate a 37.5% rise along the lower wall with a decrease at the throat of the stenosis and a decreasing profile along the downstream. The peak Von Mises stress is reached at the stenosis inlet, and the outlet along the branches experiences relatively low Von Mises stress values. The results suggest that the pre-stenotic region along the upstream is more susceptible to undergoing endothelial dysfunction across the lower and upper arterial walls with the lower wall confining higher probability.

Reduced fetal ductus venosus shunt fraction is associated with adverse perinatal outcomes in pregnancy with pregestational diabetes mellitus.

We aimed to determine fetal liver perfusion in PGDM and GDM pregnancies and to assess the relation of ductus venosus (DV) shunt fraction with adverse pregnancy outcomes. We conducted a prospective longitudinal observational study including 188 pregnant women: group I-patients with pregestational DM (PGDM, n = 86), group II-patients with gestational DM (GDM, n = 44), group III-control (n = 58). The patients included in the study underwent ultrasound examination at 30+0-40+0weeks of pregnancy. We evaluated volumetric blood flow adjusted to EFW (Q, ml/min/kg) for umbilical vein, DV, left and main portal vein. The relative risk was calculated for adverse pregnancy outcomes. In PGDM pregnancies, umbilical blood flow was redistributed to the fetal liver, increasing left portal and total liver volumetric blood flow (p < 0.001) compared with GDM and control groups. Pathological reduction in the DV shunt fraction (≤ 16.5%) was associated with an increased relative risk of preterm delivery (3.61 [95%CI 1.68; 7.71]), LGA-birth (1.64 [95% CI 1.26; 2.12]), neonatal adiposity (1.53 [95%CI 1.18; 1.98]), fetal hypoxia (3.47 [95%CI 1.34; 9.05]), emergency cesarean Sect.(1.93 [95%CI 1.26; 2.97]), and neonatal intensive care unit stay of more than 5days (1.78 [95%CI 1.08; 2.93]). Decreased DV shunt fraction reflects changes in fetal hemodynamics in PGDM-pregnancies and associated with an increased risk of adverse perinatal outcomes.

Tissue Perfusion and Biomarkers Assessment Following Root Coverage Procedures.

To assess tissue perfusion changes and wound healing biomarker levels after root coverage procedures with coronally advanced flap in combination with the cross-linked xenogeneic collagen matrix (CCMX), loaded either with a placebo or recombinant human platelet-derived growth factor-BB (rhPDGF). This study was designed as a secondary analysis from a previously published clinical trial, and it assessed the tissue perfusion changes over 6 months around multiple gingival recession defects, treated with either with CCMX alone (control) or with CCMX + rhPDGF (test). High frequency Doppler ultrasonography (HFUS) scans were obtained at sites of interest at baseline, 2 weeks, 3 months, and 6 months after surgery. Dynamic tissue perfusion measurements (DTPMs) were performed at the midfacial, interproximal, and transverse aspects of the teeth by an operator, blinded to treatment allocation, using a software package. The expression of different wound healing biomarkers from the gingival crevicular fluid was also assessed. The regression analyses showed similar tissue perfusion changes between the two groups throughout the majority of the 6 months. DTPMs at 2 weeks showed the test group to have significantly higher perfusion relief intensity (pRI, p < 0.001), mean perfused area (pA, p < 0.001), mean blood flow intensity (FImean, p = 0.021), and total blood flow intensity (FItot, p = 0.021) at the graft region of interest (ROI) compared to control sites. The test sites also exhibited significantly greater pA (p = 0.033) and blood flow intensity "blue" (FIblue, meaning flow away from the transducer, p = 0.035) at the level of the flap compared to the control sites. At 2 weeks, FIblue of the graft was directly correlated with the final mean root coverage (p = 0.008) and complete root coverage (p = 0.003). FImean and FItot of the graft exhibited a direct correlation with volume gain at 6 months (p = 0.031 for both parameters). The final GT gain was correlated to the early DTPMs (pA and FIblue) of the graft and the flap. The two groups exhibited different expressions of IL-1β, PDFG-BB, and VEGF over 3 months, with the 1-week levels of PDGF-BB that were associated with time to recovery. HFUS allowed exquisite assessment of tissue perfusion occurring at the entire surgical reconstructive regions and also within the flap and the graft. Sites treated with CCMX + rhPDGF exhibited higher DTPMs, primarily within the graft and flap ROIs at the 2-week timepoint compared to sites augmented with CCMX + saline. Early DTPMs at the graft and flap ROIs showed associations with PROMs and the final clinical outcomes. ClinicalTrials.gov: NCT04462237.

Cardiac Biomarkers, Subclinical Brain Vascular Changes, and Cognitive Decline: Post Hoc Analysis of the SPRINT Trial.

The association between subclinical cardiovascular disease (CVD) and cognitive decline in hypertensive adults and the underlying brain pathologies remain unclear. It is also undetermined whether intensifying blood pressure (BP) treatment slows down cognitive decline associated with subclinical CVD. We conducted a post hoc analysis of the Systolic Blood Pressure Intervention Trial. Subclinical CVD at baseline was identified by elevated levels of high-sensitivity cardiac troponin T (hs-cTnT≥14ng/L) and N-terminal pro-B-type natriuretic peptide (NT-proBNP≥125 pg/mL). Global cognitive function and domain-specific measures (memory, processing speed, language, and executive function) were assessed at baseline and follow-up (years 2, 4, and 6) in 2733 participants. White matter lesions, cerebral blood flow, and brain tissue volume were assessed by MRI at baseline and years 4 in a subset of 639 participants. Both elevated hs-cTnT and NT-proBNP levels at baseline were associated with accelerated cognitive decline across all domains after adjusting for potential confounding factors. The group with elevated levels of both cardiac biomarkers showed the fastest decline, with a larger annual decline rate of 0.033 (95% CI: 0.024-0.041) in the z-score of global cognitive function compared to the group with normal levels. Elevated levels of both biomarkers were also associated with a faster progression in white matter lesions, but not with changes in total brain tissue volume or cerebral blood flow. Intensive BP treatment did not attenuate these associations compared to standard treatment. Subclinical CVD may contribute to faster white matter lesion progression and accelerated cognitive decline in patients with hypertension, regardless of intensive BP treatment.

Cardiac Biomarkers, Subclinical Brain Vascular Changes, and Cognitive Decline: Post Hoc Analysis of the SPRINT Trial

AbstractBackgroundSubclinical cardiovascular disease (CVD), assessed by high‐sensitivity cardiac troponin T (hs‐cTnT) and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP), is linked to cognitive decline, but the associations in hypertensive adults and the underlying brain pathologies remain unclear. It is also undetermined whether an intensive blood pressure treatment compared to a standard treatment may slow down cognitive decline associated with subclinical CVD.MethodWe conducted a post hoc analysis of the Systolic Blood Pressure Intervention Trial, where older adults with hypertension were randomized to an intensive treatment (systolic blood pressure (SBP) target of &lt; 120 mm Hg) or standard treatment (&lt; 140 mm Hg). Serum hs‐cTnT and NT‐proBNP concentrations were measured at baseline, with elevated levels defined as ≥ 14 ng/L for hs‐cTnT and ≥ 125 pg/mL for NT‐proBNP. Global and domain‐specific (memory, processing speed, language, and executive function) cognitive function was assessed using a battery of neuropsychological tests at baseline and during the follow‐up (year 2, year 4, and year 6) in 2733 participants with biomarker measurements. White matter lesions, cerebral blood flow, and brain tissue volume were assessed by brain MRI at baseline and 4 years of follow‐up in a subset of 639 participants.ResultElevated levels of both hs‐cTnT and NT‐proBNP were associated with accelerated decline in cognitive function across all four domains after adjusting for potential confounding factors. The group with elevated levels of both cardiac biomarkers showed the fastest decline, with a greater annual decline rate of 0.033 (95% CI, 0.024 to 0.041) in standardized z‐score of global cognitive function compared to the group with normal hs‐cTnT and NT‐proBNP. Elevated levels of both cardiac biomarkers were also associated with a faster progression in white matter lesions, but not with changes in total brain tissue volume and cerebral blood flow. Intensive SBP treatment did not attenuate these associations compared to standard treatment (all P for interaction &gt; 0.05).ConclusionElevated hs‐cTnT and NT‐proBNP levels were associated with accelerated cognitive decline and progression of white matter lesions regardless of SBP treatment assignment. Subclinical CVD may contribute to the progression of white matter lesions and thus leads to accelerated cognitive decline.

Effects of intracoronary supersaturated oxygen infusion on the time course of myocardial blood flow and extent of microvascular obstruction in an ischemia/reperfusion preclinical swine model

Abstract Introduction Despite successful epicardial reperfusion with primary PCI, reactive changes in microvascular function lead to impaired myocardial reperfusion. Intracoronary SuperSaturated Oxygen Therapy (SSO2) is the only approved therapy that improves myocardial salvage in STEMI pts through the delivery of hyperbaric levels of oxygen to viable ischemic vascular and myocardial cells. Several important questions remain unanswered regarding the potential mechanisms of this benefit. Therefore, the purpose of this study is to determine the effects of SSO2 on the time course of myocardial blood flow (MBF) and the extent of microvascular obstruction (MVO) in an ischemia/reperfusion model. Methods 10 swine (32-40 kg) surviving 90-minute balloon-induced anterior STEMI, and 15-min auto reperfusion, were assigned to 120-min of SSO2 (n=5) or control (n=5) with 120-min auto reperfusion. MBF was evaluated at various time points during the experiment by injection of 15–µm microspheres (BioPal, USA) through a catheter placed in the left ventricle. Before euthanasia, 4% thioflavin-S (TS) was injected into the left anterior descending artery. The left ventricle was sectioned into 10-mm thick slices, and the myocardial rings were photographed under UV light to determine areas at risk (TS positive), MVO (lack of TS staining within TS positive area), and remote zones (contiguous areas unstained by TS). MBF was calculated as the total blood flow within the areas at risk normalized to the total flow within the remote zones. Results All animals experienced significant reduction (p = 0.02) in MBF due to balloon occlusion at the 85-minute MI timepoint compared to baseline (Fig). Following the removal of occlusion, reactive hyperemic flows were observed for both groups at the 15-minute auto reperfusion time point (Fig). Starting at the 30-min time point of autoperfusion to 120-min, the MBF significantly decreased (p=0.02) in the controls (Fig). In contrast during these time points, for the SSO2 group the MBF values were numerically higher than the controls, with average MBF for the SSO2 group being significantly higher (p = 0.03) than the controls (1.1 ± 0.18 vs 0.6 ± 0.13, respectively) at the 120-min timepoint (Fig). MVO was found within the areas at risk in all animals, but the extent of MVO in relation to the area at risk was significantly reduced (p &amp;lt; 0.001) in the SSO2 group versus controls (15.2 ± 7.3% vs 41.8% ± 6.2%, respectively). Conclusions Results from this study showed that in a STEMI swine model, SSO2 prevented reduction in MBF during the 120-min reperfusion period, with significantly increased MBF at the end of the experiment compared to controls. This flow improvement translated to a 64% relative reduction in the extent of MVO compared to controls. These results suggest that one of the mechanisms by which SSO2 improves myocardial salvage may be by limiting early microcirculatory alterations set in motion by a cascade of reduced myocardial flow and MVO.Myocardial Blood Flow vs Time

Patients with amnestic mild cognitive impairment have higher cerebrovascular impedance than cognitively normal older adults.

Brain hypoperfusion is associated with cognitive impairment. Higher cerebrovascular impedance modulus (Z) may contribute to brain hypoperfusion. We tested hypotheses that patients with amnestic mild cognitive impairment (aMCI) (i.e., those who have a high risk of developing Alzheimer's disease) have higher Z than age-matched cognitively normal individuals, and that high Z is correlated with brain hypoperfusion. Fifty-eight patients with aMCI (67 ± 7 yr) and 25 cognitively normal subjects (CN, 65 ± 6 yr) underwent simultaneous measurements of carotid artery pressure (CAP, via applanation tonometry) and middle cerebral arterial blood velocity (CBV, via transcranial Doppler). Z was quantified using cross-spectral and transfer function analyses between dynamic changes in CBV and CAP. Patients with aMCI exhibited higher Z than NC (1.18 ± 0.34 vs. 1.01 ± 0.35 mmHg/cm/s, P = 0.044) in the frequency range from 0.78 to 4.29 Hz. The averaged Z in the frequency range (0.78-3.13 Hz) of high coherence (>0.9) was inversely correlated with total cerebral blood flow measured with 2-D Doppler ultrasonography normalized by the brain tissue mass (via structural MRI) across both patients with aMCI and NC (r = -0.311, P = 0.007), and in patients with aMCI alone (r = -0.306, P = 0.007). Our findings suggest that patients with aMCI have higher cerebrovascular impedance than cognitively normal older adults and that increased cerebrovascular impedance is associated with brain hypoperfusion.NEW & NOTEWORTHY This is the first study to compare cerebrovascular impedance between patients with amnestic mild cognitive impairment (aMCI) and age-matched cognitively normal individuals. Patients with aMCI had higher cerebrovascular impedance modulus than age-matched cognitively normal individuals, which was correlated with brain hypoperfusion. These results suggest the presence of cerebrovascular dysfunction in the dynamic regulation of cerebral blood flow in older adults who have high risks of Alzheimer's disease.

Ultrasonographic Assessment of Testicular Biometry and Arterial Blood Flow in Pre- and Postpubertal Miranda Donkeys: Correlations With Semen Quality Parameters.

The main goals of this study were to document and compare the normal ranges of testicular haemodynamic parameters in pre- (aged 8-12 months; n = 4) and postpubertal (aged 24-259 months; n = 16) Miranda donkeys in the breeding season, and to correlate animal biometric data and testicular Doppler indices with basic semen quality parameters of sexually mature jacks. Colour and pulsed-Doppler ultrasonography were employed to assess blood flow in the left and right distal supratesticular artery (DsTA) and their marginal branches (marginal arteries-MA). Peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) and resistive index (RI) were evaluated in both blood vessels, and TAMV (time-averaged mean velocity), TABF (total arterial blood flow) and TABF rate (TABF-R) were calculated for MA. The mean diameter of MA was greater (p < 0.05; 0.24 ± 0.05 vs. 0.19 ± 0.05 cm; mean ± SD) but TABF-R was less (p < 0.05; 0.004 ± 0.004 vs. 0.02 ± 0.01 mL/s/cm3) in sexually mature donkeys compared with prepubertal animals. Apart from RI values for the right testicle of prepubertal donkeys, PI and RI were consistently greater (p < 0.05) in DsTA compared with MA. Significant correlations were found among select biometric and haemodynamic attributes of the testes (height, width and length, TV, TTV and PSV-ST) and ejaculate characteristics (volume, sperm defects-total, head and midpiece) in sexually mature donkeys (n = 8). The present results highlight the importance of scrotal ultrasonography for the reproductive assessment of jacks and provide reference values, based on the available subpopulation of Miranda donkeys that can be used in their clinical and reproductive management and research, or conservation programmes.

Артериальное и венозное кровообращение у пациентов с выраженным стенозом внутренних сонных артерий до и в разные сроки после проведения каротидной эндартерэктомии

In continuation of earlier studies of the features of venous outflow from the head and neck in patients with varying degrees of stenosis of the internal carotid arteries (ICA), in this article the authors present data on the features of arterial inflow and venous outflow in patients with a high degree of stenosis before and at different periods after carotid endarterectomy. Material and methods 30 patients with stenosis ˃ 60%, were examined before and after surgery at 10-14 days, 6 months and 1 year. The control group consisted of 30 patients without ICA stenosis and signs of systemic and regional phlebohypertension. The results were compared with the control and between the groups. Results The study has shown that venous outflow through the PV in orthostasis at different times after CEAE prevailed over venous outflow in clinostasis. The average values of the total volumetric blood flow through the PV statistically significantly increase after surgery in both clinostasis and orthostasis. Conclusions The presence of phlebohypertension with severe stenosis of the ICA may indicate a relationship between atherosclerotic lesions of the ICA and changes in venous outflow and the formation of systemic or regional phlebohypertension. When restoring blood flow through the ICA with stenosis ˃ 60% after CEAE, the predominance of venous outflow remains in the horizontal position along the IJV system.

Prediction of the response to antiangiogenic sunitinib therapy by non-invasive hybrid diffuse optics in renal cell carcinoma.

In this work, broadband diffuse reflectance spectroscopy (DRS) and diffuse correlation spectroscopy (DCS) were used to quantify deep tissue hemodynamics in a patient-derived orthotopic xenograft mouse model of clear cell renal cancer undergoing antiangiogenic treatment. A cohort of twenty-two mice were treated with sunitinib and compared to thirteen control untreated mice, and monitored by DRS/DCS. A reduction in total hemoglobin concentration (THC, p = 0.03), oxygen saturation (SO2, p = 0.03) and blood flow index (BFI, p = 0.02) was observed over the treatment course. Early changes in tumor microvascular blood flow and total hemoglobin concentration were correlated with the final microvessel density (p = 0.014) and tumor weight (p = 0.024), respectively. Higher pre-treatment tumor microvascular blood flow was observed in non-responder mice with respect to responder mice, which was statistically predictive of the tumor intrinsic resistance (p = 0.01). This hybrid diffuse optical technique provides a method for predicting tumor intrinsic resistance to antiangiogenic therapy and could be used as predictive biomarker of response to antiangiogenic therapies in pre-clinical models.

Evaluation of novel balloon pulmonary angioplasty using intravascular ultrasound for total occlusion lesions and blood flow in the postprocedural phase after initially unsuccessful procedures.

Outcomes of balloon pulmonary angioplasty (BPA) using intravascular ultrasound (IVUS) with a rounded tip to cross a total occlusion lesion in chronic thromboembolic pulmonary hypertension without passing a conventional guidewire remain unclear. Even in initially unsuccessful cases of total occlusion lesions, improved blood flow may be observed in the postprocedural phase as a result of breaking the thrombosis cap surface. The aim of the study was to verify the initial success of BPA with a new technique using IVUS for total occlusion lesions and to evaluate peripheral blood flow in the postprocedural phase in initially unsuccessful cases. Initial success rate and associated factors were evaluated in 50 total occlusion lesions by attempted IVUS passage using a new technique without a preceding guidewire from August 2016 to February 2024. Peripheral blood flow improvement in the postprocedural phase among initially unsuccessful cases was investigated via subsequent angiographic examination or during follow-up. The success rate was 54%, and the sole determinant of success was the angle of the lesion. Peripheral perfusion improved in 15 of 23 initially unsuccessful cases in the postprocedural phase. Even in the unsuccessful cases, significant improvement in peripheral perfusion occurred in the postprocedural phase in the patients undergoing dilatation with the balloon advanced partway into the total occlusion lesion to confirm intravascular location of the balloon (P = .0257). BPA treatment of total occlusion lesions may improve perfusion in the postprocedural phase even following an initially unsuccessful treatment. Maximizing use of IVUS may provide an adjunctive role in BPA of total occlusion lesions.

Preclinical Female Model of Urogenital Dysfunction and Pathophysiological Changes After Pelvic Radiation Therapy.

Introduction Radiation therapy (RT) is the gold standard for many pelvic cancers and improves overall patient survival. However, pelvic RT is associated with increased sexual dysfunction and urinary incontinence. Although the side effects of pelvic RT are well-documented, the pathological mechanisms leading to pelvic organ dysfunction are unknown, and a preclinical model has not been established. This study characterized the impact of pelvic RT at early and late timepoints on female rat bladder, vaginal, and urethral physiology and morphology. Methods Adult female Sprague-Dawley rats were divided into three groups (n = 8/group): (I) Sham, (II) four weeks RT (4wk RT), and (III) nine weeks RT (9wk RT). The RT groups received a single dose of 20 Gy external beam radiation, and experiments were conducted at 4wk and 9wk post-RT. Nerve-mediated vaginal blood flow was measured via laser Doppler. Tissue bath studies assessed vaginal contractility to electric field stimulation (EFS), adrenergic and cholinergic agonists, and relaxation to a nitric oxide donor. Bladder and urethral sphincters were evaluated for cholinergic, caffeine, and EFS-mediated contractility. Quantitative polymerase chain reaction (qPCR) measured gene expression of markers of oxidative stress. Vaginal, bladder, and urethral fibrosis were assessed with Masson's trichrome staining. Results At 4wk post-RT, total vaginal blood flow decreased, and at 9wk post-RT, returned to baseline levels. At 9wk post-RT, vaginal neurogenic and adrenergic-mediated contractile responses increased significantly. Vaginal epithelial thickness decreased post-RT and correlated with an acute rise in vaginal inflammatory gene expression. At 4wk post-RT, bladder neurogenic contractions decreased and remained lowered. Internal urethral contractions increased at 4wk post-RT and returned to Sham levels after 9wk post-RT. Pelvic RT increased external urethral neurogenic contractions, which remained elevated. Conclusion This novel preclinical model provides valuable insights into the temporal pathophysiology of pelvic RT-induced sexual and urinary dysfunction. The establishment of this model is crucial for understanding the underlying mechanisms involved in RT-induced pelvic injury. A reliable, clinically relevant model will allow for the testing of therapeutic strategies to prevent adverse effects with RT in pelvic cancer survivors.

Some questions about a new study of coefficient microcirculation in example in patients with limb-threatening ischemia and intermittent claudication

BACKGROUND: Limb-threatening ischemia is one of more important problem of fundamental and practice modern angiology. Despite the development of modern diagnostic and therapeutic approaches good results, Limb-Threatening Ischemia deserves special attention and occupies a special place among medical, biomedical and socio-economic problems. A comprehensive study will make it possible to develop new approaches, the result of which should be a decrease in the total number of diseases, as well as a minimization of complications leading to large-scale tissue losses and amputations. OBJECTIVE: We set out to develop a new non-invasive method for studying microcirculation in patients with limb-threatening ischemia. METHODS: We investigated control group and adults of both sexes (age: 50–75 years) with a confirmed diagnosis of the claudication. Men and women in ratio 1 : 1 in control and target groups. RESULTS: The research results showed that the original microcirculation coefficient calculated according to our algorithm in patients with intermittent claudication was 70% better than in the control group and 120% of patients were worse than in patients with Limb-Threatening Ischemia. CONCLUSION: Our research team created an original so called coefficient of microcirculation. In order to determine it, we studied the blood flow in the pulsations on the left and right side of the posterior tibial arteries of the legs at rest (names of lines SIN F, DEX F) and during post-ischemic hyperemia in the same lines. The study of microcirculation based on the microcirculation coefficient is very informative. The importance of this methodology for studying the total peripheral blood flow and arteriolar response is due to fundamental and clinical developments, as well as financial costs. Considering the technique described in the article can be easily mastered by medical personnel, it is easy to use in the inpatient and outpatient sectors, its use does not require large areas of the medical facility, the equipment is not expensive and the test itself does not cause inconvenience to the patient, then we can recommend including the described method is included in the list of functional diagnostic tests as a direct and quantitative method for determining microcirculation (without special costs on the part of medical institutions, insurance companies and the patient).

The role of umbilical-portal venous hemodynamics in fetal macrosomia pathogenesis in pregnancy complicated by diabetes mellitus

BACKGROUND: During pregnancy complicated by diabetes mellitus, the risks of developing fetal macrosomia and other perinatal complications increase. Redistribution of blood flow in the fetal umbilical-portal venous system may be an important but poorly understood compensatory mechanism that affects macrosomic fetal growth. AIM: The aim of this study was to determine the features of the fetal umbilical-portal venous hemodynamics in pregnant women with various types of diabetes mellitus and the absence of carbohydrate metabolism disorders, taking into account the gestational age and the macrosomic fetal growth. MATERIALS AND METHODS: In this prospective cohort study, 86 pregnant women with pregestational diabetes mellitus, 44 pregnant women with gestational diabetes mellitus and 58 patients without carbohydrate metabolism disorders underwent ultrasound examinations from 30+0 to 41+3 weeks of gestation. During ultrasound, we performed Doppler assessment of venous hemodynamic parameters in the vessels of the umbilical-portal venous system, with volumetric blood flow calculated for each vessel. Additionally, the total liver volumetric blood flow and ductus venosus shunt fraction were calculated. RESULTS: The presence of fetal macrosomia in patients from the pregestational diabetes mellitus group is associated with an increase in the volumetric blood flow of the umbilical vein by 89.5 ml/min (p = 0.003) and the left portal vein by 33.3 ml/min (p = 0.008), as well as the total volumetric blood flow of the fetal liver by 95.7 ml/min (p = 0.001) compared with normal-weight fetuses. At the same time, the ductus venosus shunt fraction decreased in macrosomic fetuses by 3.83% (p = 0.001). In the gestational diabetes mellitus and control groups, despite the tendency for these parameters to increase in fetuses with macrosomia, the differences did not reach statistical significance. With a left portal vein volume flow threshold of 94.51 ml/min, the sensitivity and specificity for predicting large births were 84.46 and 72.09%, respectively. CONCLUSIONS: Pregestational diabetes mellitus in the mother is associated with a priority redistribution of blood flow to the fetal liver and is accompanied by a decrease in the ductus venosus shunt fraction. The severity of these hemodynamic changes increases in the presence of fetal macrosomia, which confirms the role of liver perfusion in the regulation of fetal growth in uncomplicated pregnancy and maternal diabetes mellitus.

Investigations of Differential Hypoxemia During Venoarterial Membrane Oxygenation with and Without Impella Support

PurposeVenoarterial extracorporeal membrane oxygenation (VA ECMO) is used in patients with refractory cardiac or cardio-pulmonary failure. Native ventricular output interacts with VA ECMO flow and may hinder sufficient oxygenation to the heart and the brain. Further on, VA ECMO leads to afterload increase requiring ventricular unloading. The aim of the study was to investigate aortic blood flow and oxygenation for various ECMO settings and cannula positions with a numerical model.MethodsFour different aortic cannula tip positions (ascending aorta, descending aorta, abdominal aorta, and iliac artery) were included in a model of a human aorta. Three degrees of cardiac dysfunction and VA ECMO support (50%, 75% and 90%) with a total blood flow of 6 l/min were investigated. Additionally, the Impella CP device was implemented under 50% support condition. Blood oxygen saturation at the aortic branches and the pressure acting on the aortic valve were calculated.ResultsA more proximal tip orientation is necessary to increase oxygen supply to the supra-aortic and coronary arteries for 50% and 75% support. During the 90% support scenario, proper oxygenation can be achieved independently of tip position. The use of Impella reduces afterload by 8–17 mmHg and vessel oxygenation is similar to 50% VA ECMO support. Pressure load on the aortic valve increases with more proximal tip position and is decreased during Impella use.ConclusionsWe present a simulation model for the investigation of hemodynamics and blood oxygenation with various mechanical circulatory support systems. Our results underline the intricate and patient-specific relationship between extracorporeal support, cannula tip orientation and oxygenation capacity.

Bi-regional dynamic contrast-enhanced MRI for prediction of microvascular invasion in solitary BCLC stage A hepatocellular carcinoma

ObjectivesTo construct a combined model based on bi-regional quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), as well as clinical-radiological (CR) features for predicting microvascular invasion (MVI) in solitary Barcelona Clinic Liver Cancer (BCLC) stage A hepatocellular carcinoma (HCC), and to assess its ability for stratifying the risk of recurrence after hepatectomy.MethodsPatients with solitary BCLC stage A HCC were prospective collected and randomly divided into training and validation sets. DCE perfusion parameters were obtained both in intra-tumoral region (ITR) and peritumoral region (PTR). Combined DCE perfusion parameters (CDCE) were constructed to predict MVI. The combined model incorporating CDCE and CR features was developed and evaluated. Kaplan–Meier method was used to investigate the prognostic significance of the model and the survival benefits of different hepatectomy approaches.ResultsA total of 133 patients were included. Total blood flow in ITR and arterial fraction in PTR exhibited the best predictive performance for MVI with areas under the curve (AUCs) of 0.790 and 0.792, respectively. CDCE achieved AUCs of 0.868 (training set) and 0.857 (validation set). A combined model integrated with the α-fetoprotein, corona enhancement, two-trait predictor of venous invasion, and CDCE could improve the discrimination ability to AUCs of 0.966 (training set) and 0.937 (validation set). The combined model could stratify the prognosis of HCC patients. Anatomical resection was associated with a better prognosis in the high-risk group (p < 0.05).ConclusionThe combined model integrating DCE perfusion parameters and CR features could be used for MVI prediction in HCC patients and assist clinical decision-making.Critical relevance statementThe combined model incorporating bi-regional DCE-MRI perfusion parameters and CR features predicted MVI preoperatively, which could stratify the risk of recurrence and aid in optimizing treatment strategies.Key PointsMicrovascular invasion (MVI) is a significant predictor of prognosis for hepatocellular carcinoma (HCC).Quantitative DCE-MRI could predict MVI in solitary BCLC stage A HCC; the combined model improved performance.The combined model could help stratify the risk of recurrence and aid treatment planning.Graphical

Comparing Vascular Morphology and Hemodynamics in Patients with Vein of Galen Malformations Using Intracranial 4D Flow MRI.

Vein of Galen malformation (VOGM) is the most common congenital cerebrovascular malformation, and many patients have high mortality rates and poor cognitive outcomes. Quantitative diagnostic tools are needed to improve clinical outcomes, and the purpose of this study was to characterize intracranial blood flow in VOGM using quantitative 4D flow MRI. A prospective study of children with VOGM was conducted by acquiring 4D flow MRI to quantify total blood inflow to the brain, flow in the pathologic falcine sinus, and flow in the superior sagittal sinus. Linear regression was used to test the relationships between these flows and age, clinical status, and the mediolateral diameter of the outflow tract of the lesion through the falcine or straight sinus diameter, which is a known morphologic prognostic metric. In all 11 subjects (mean age, 22 [SD,17 ] weeks), total blood flow to the brain always exceeded normal levels (mean, 1063 [SD, 403] mL/minute). Significant correlations were observed between falcine sinus flow and the mediolateral diameter of the straight or falcine sinus, the posterior cerebral artery/MCA flow ratio and age at scanning, and superior sagittal sinus flow proximal to malformation inflow and age at scanning. Using 4D flow MRI, we established the hemodynamic underpinnings of the mediolateral diameter of the straight or falcine sinus and investigated metrics representing parenchymal venous drainage that could be used to monitor the normalization of hemodynamics during embolization therapy.

Artificial Intelligence–Enabled Quantitative Coronary Plaque and Hemodynamic Analysis for Predicting Acute Coronary Syndrome

A lesion-level risk prediction for acute coronary syndrome (ACS) needs better characterization. This study sought to investigate the additive value of artificial intelligence-enabled quantitative coronary plaque and hemodynamic analysis (AI-QCPHA). Among ACS patients who underwent coronary computed tomography angiography (CTA) from 1month to 3 years before the ACS event, culprit and nonculprit lesions on coronary CTA were adjudicated based on invasive coronary angiography. The primary endpoint was the predictability of the risk models for ACS culprit lesions. The reference model included the Coronary Artery Disease Reporting and Data System, a standardized classification for stenosis severity, and high-risk plaque, defined as lesions with≥2 adverse plaque characteristics. The new prediction model was the reference model plus AI-QCPHA features, selected by hierarchical clustering and information gain in the derivation cohort. The model performance was assessed in the validation cohort. Among 351 patients (age: 65.9 ± 11.7 years) with 2,088 nonculprit and 363 culprit lesions, the median interval from coronary CTA to ACS event was 375days (Q1-Q3: 95-645days), and 223 patients (63.5%) presented with myocardial infarction. In the derivation cohort (n=243), the best AI-QCPHA features were fractional flow reserve across the lesion, plaque burden, total plaque volume, low-attenuation plaque volume, and averaged percent total myocardial blood flow. The addition of AI-QCPHA features showed higher predictability than the reference model in the validation cohort (n=108) (AUC: 0.84 vs 0.78; P< 0.001). The additive value of AI-QCPHA features was consistent across different timepoints from coronary CTA. AI-enabled plaque and hemodynamic quantification enhanced the predictability for ACS culprit lesions over the conventional coronary CTA analysis. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary Computed Tomography Angiography and Computational Fluid Dynamics II [EMERALD-II]; NCT03591328).

The Impact of Aging and Biological Sex on Diaphragm Hyperemia and Blood Flow Distribution

INTRODUCTION: Age-related respiratory muscle dysfunction (i.e., the diaphragm) diminishes physical capacity and increases the susceptibility to respiratory failure. The diaphragm dysfunction associated with old age is characterized by decreased diaphragm muscle mass and strength, and increased fatiguability. While inadequate perfusion and diminished microvascular function are well recognized to play a central role in age-related peripheral skeletal muscle dysfunction, the impact of aging on diaphragm hyperemia and blood flow distribution, and whether sex differences exist, has not been investigated. METHODS: Young (Y; 4-6 months) and Old (O; 22-24 months) Fischer 344 rats (n=34) were divided into four groups: 1) Young female (YF; n=8), 2) Young male (YM; n=8), 3) Old female (OF; n=9), and 4) Old male (OM; n=9). Fluorescent microspheres were used to assess bulk and regional diaphragm blood flow at rest and during electrically-induced 1Hz contractions. RESULTS: There were no age-related or sex differences in quiescent diaphragm blood flow (BF) or vascular conductance (VC) ( P&gt;0.05). Age-related differences during 1Hz contractions: The increase in total diaphragm BF was significantly lower in OM (98 ± 11 ml/min/100g) compared to YM (141 ± 7 ml/min/100g; p&lt;0.05). Total and regional diaphragm BF was not different in F rats ( P&gt;0.05); however, medial costal diaphragm VC was decreased in OF (1.2 ± 0.1 ml/mmHg/min/100g) compared to YF (1.8 ± 0.2 ml/mmHg/min/100g; p&lt;0.05). Sex differences during 1Hz contractions: Total diaphragm BF and VC were similar in YF and YM ( P &gt; 0.05). While both ventral and medial costal diaphragm BF responses were not different between YF and YM, dorsal costal diaphragm BF was higher in YF (144 ± 27 ml/min/100g) versus YM (84 ± 11 ml/min/100g; p&lt;0.05). Total and regional (ventral, medial, and dorsal costal) diaphragm BF was significantly higher in OF compared to OM ( p&lt;0.05). CONCLUSION: These data demonstrate that aging impaired the ability of the diaphragm to augment BF in response to contractile activity in M rats and decreased medial costal diaphragm VC during contractions in F rats with no significant effect on diaphragmatic hyperemia. In regards to sex differences, these data suggest that both YF and OF may have a greater regional recruitment of the diaphragm compared to YM and OM. The data herein provide a putative mechanism for age-related diaphragm contractile dysfunction and future studies are needed to investigate the impact of aging and biological sex on diaphragm vascular function. National Institute of Aging 1R15AG078060, Ruth L. Kirschstein National Research Service Awards from the National Heart, Lung, and Blood Institute 1F31HL167618-01 and 1F31HL170643-01, and Sustained Momentum for Investigators with Laboratories Established (SMILE) Grants at Kansas State University. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.