Vein Blood Flow Research Articles

Role of intravascular ultrasound in endovascular management of nutcracker syndrome: A case report.

Here, we describe nutcracker syndrome management using intravascular ultrasound (IVUS) during endovascular stent placement of the renal vein. A 60-year-old woman with a known Factor V Leiden mutation, long-standing smoking history, and family history of pancreatic cancer presented with 2years of intermittent left upper quadrant pain (LUQ) and a 15lb unintentional weight loss. Work-up included abdominal ultrasound (US) and abdominal computerized tomography (CT) scan. Abdominal US and Chest CT scan were negative while the abdominal CT scan revealed severe compression of the left renal vein by the superior mesenteric artery, consistent with nutcracker syndrome. Renal venogram and endovascular stent placement performed under IVUS guidance. IVUS was used to determine stent size and measure flow and assess patency after stent placement. Post-renal vein stent placement, the patient had resolution of her symptoms with follow-up duplex renal ultrasound exam demonstrating restored blood flow in the left renal vein with improved patency.

Four-dimensional flow MR imaging for evaluating treatment response after transcatheter arterial chemoembolization in cirrhotic patients with hepatocellular carcinoma.

To prospectively evaluate the potential of four-dimensional (4D) flow magnetic resonance imaging (MRI) in predicting treatment responses after transcatheter arterial chemoembolization (TACE) in cirrhoticpatients with hepatocellular carcinoma (HCC). A total of 195 patients were classified into four groups (A-D): A, cirrhotic patients without HCC (n = 30); B, cirrhotic patients with HCC before TACE (n = 75); C, cirrhotic patients with HCC showing an incomplete response following TACE (n = 56); and D, cirrhotic patients with HCC achieving a complete response (CR) following TACE (n = 34). The patients were subjected to routine laboratory tests and 4D flow MRI using a 3-T MRI system to measure the quantitative parameters of blood flow in the portal vein (PV), splenic vein(SV), and superior mesenteric vein. The data collected by 4D flow MRI were compared among the groups using one-way analysis of variance. A multivariate analysis was performed to verify the association of clinical characteristics and 4D flow parameters with CR after TACE treatment. The average through-plane velocity, peak velocity magnitude, average net flow, peak flow, and net forward volume in the PV and SVwere significantly lower in groups B and C (P < 0.05) compared to those in group A. Moreover, average through-plane velocity and peak velocity magnitude in the PV in groups B and C were significantlylower than those in group D (P < 0.05). The multivariate analysis demonstrated that the average through-plane velocity and peak velocity magnitudein the PV were independently associated with CR in HCC patients after TACE (P < 0.05). The quantitative flow data obtained by 4D flow MRI may be useful for predicting CR after TACE in cirrhotic patients with HCC.

The effectiveness of splenorenal shunt in the correction of portal hypertension and hypersplenism in the long-term period

The aim is to evaluate the long-term results of splenorenal anastomosis (SRA) in the treatment of portal hypertension a year or more after surgery. Materials and methods. The long-term results of the imposition of CPA after one to ten years have been studied. Life expectancy, the number of bleeding recurrences, and the severity of thrombocytopenia were assessed based on the results of fibrogastroscopy, duplex scanning (DS), and computed tomography with bolus enhancement. Results. One-year survival rate was 96.77%, three-year - 87.09%, five-year - 74.19%, ten-year - 22.58%. Within three years after bypass surgery, no recurrence of bleeding was observed, while in half of the patients (54.28%) the varicose veins of the esophagus disappeared, in the rest (45.72%) they decreased to grade I. Recurrence of bleeding occurred in six patients (17.14%) after 5-13 years, in one case massive, which was accompanied by shunt thrombosis (2.85%) according to the results of DS. For the rest, its function was preserved. The median platelet count one year and three after CP did not differ and was 110 x109 and 105 x109. It was found that the larger the diameter of the portal vein and the lower the volume velocity of blood flow in it, the smaller was the increase in platelets in the long-term period (r=0.90, p=0.037; r=0.87, p=0.01). Conclusions. After performing splenorenal bypass surgery for portal hypertension for the purpose of primary and secondary prevention of gastric bleeding, its recurrence occurred in 17.14% 5-13 years after surgery. After the correction of portal hypertension, there was a tendency to increase the number of platelets in the long-term postoperative period, which was dependent on the volume velocity of blood flow in the portal vein and the degree of its expansion before surgical treatment.

Effect of Compression Garments on the Ventilatory Function After Abdominoplasty.

The use of compression garments in the postoperative period of abdominoplasty seems to be a consensus, but the incidents of complications arising from this have been described, related to an increase in intraabdominal pressure and reduction of the femoral vein blood flow that may facilitate thromboembolic events. There are no studies that have evaluated the isolated effect of postoperative compression garments on respiratory function. The purpose of this study was to evaluate the effect of compression garments on respiratory function after abdominoplasty. Thirty-four female patients who underwent standard abdominoplasty were divided into 2 groups, the garment group (n = 18) and the no garment group (n = 16). Respiratory function assessment (with spirometry and manovacuometry) was performed in the preoperative and postoperative periods. Forced vital capacity assessment revealed a greater ventilatory restriction in the garment group. Forced expiratory volume in 1 second (FEV1) showed differences between the evaluation time points in the garment group; the intergroup comparisons showed that the no garment group had a lower FEV1. Slow vital capacity was evaluated with no significant differences found on both intergroup comparisons. The inspiratory capacity was reduced in the garment group, representing ventilatory restriction. Measurements of the maximum inspiratory pressure showed no significant differences between the groups. The maximum expiratory pressure showed significantly lower values on postoperative day 7 in the garment group. The use of compression garments after abdominoplasty impairs ventilatory function. Not wearing this type of garment can improve ventilation, decreasing the risk of pulmonary complications.

Colour Doppler study of blood flow in the portal vein in relation to blood flow in the milk vein, milk yield and body condition of dairy cows during dry period and lactation

In dairy cows, the liver supports the increased nutrient demands of the udder for milk production. Blood flow is key for the transport of these nutrients. This study investigated portal vein blood flow volume (PVBFVol) in relation to daily milk yield (DMY), milk vein blood flow volume (MVBFVol) and body condition parameters of high-producing dairy cows, starting from late lactation, throughout dry period, and consecutive early lactation. Seventeen repeated examinations were performed on 19 Holstein cows and 313 measurement days were finally included. Vein morphology and blood flow were examined via B-mode and spectral Doppler (triplex) ultrasonography, respectively. Body condition parameters recorded were body condition score (BCS), backfat thickness (BFT) measurement with ultrasonography, heart girth circumference (HG) and withers height (WH). Longitudinal relationship of PVBFVol with MVBFVol, DMY, BCS, BFT, HG and WH was analyzed with linear mixed models, with random intercept effects, using restricted cubic splines. A significant increase of 8.28% (p < 0.01) in PVBFVol appeared for every 1 L/min increase in MVBFVol in the univariable model. PVBFVol presented a significant negative association with BCS (p < 0.01) and BFT (p = 0.02), while interaction with production stage was significant, too. PVBFVol significantly increased by 0.38% (p = 0.04) for every 1 kg increase in DMY in the multivariable model. In conclusion, the increased PVBFVol during lactation accompanies the escalation in metabolic activity of the liver and the increased blood circulation through the udder, coping with the udder's escalating nutrient demands for milk synthesis.

The Impact of COVID-19-Related Psychological Stress on Fetoplacental Circulation: A Doppler Scan of Umbilical Vessels in Third-Trimester Antenatal Women.

The placenta is an important organ of pregnancy. A multitude of physiological and pathological factors influence blood flow in the placenta during pregnancy. However, the fetal effects of maternal psychological stress were inconclusive. The recent COVID-19 pandemic had unprecedented economic, social, and psychological effects. The effect of COVID-19-induced psychological stress in antenatal women and its resultant fetal impact were studied by observing the Doppler waveforms of the uterine and umbilical arteries. The cross-sectional study was conducted on 26 healthy third-trimester antenatal women who satisfied pre-set inclusion and exclusion criteria. A pandemic-related pregnancy stress scale (PREPS) was used to evaluate the stress in pregnant women and categorize it into mild, moderate, and severe levels. The Doppler ultrasound of the uterine and umbilical vessels was done along with a routine growth scan in the third trimester of pregnancy. The arterial waveforms, Pulsatility index (PI) of uterine and umbilical arteries, umbilical vein blood flow, and biometric parameters of the fetus were recorded and analyzed. Seventeen of the 26 participants were found to be moderately stressed. Among the three dimensions of the PREPS tool, the perinatal infection stress dimension was expressed predominantly. A strong expression of the positive affirmation dimension was seen in antenatal women. The mean Pulsatility index in the mild, moderate, and severe groups was 0.74, 0.93, and 0.63, respectively. The association between the PREPS score and the Pulsatility index of the umbilical artery alone was found to be significant at p=0.02. The COVID-19 pandemic caused moderate to severe levels of psychological stress in pregnant women. The statistically significant association between the PREPS score and the umbilical artery PI indicates possible fetoplacental compromise, suggesting the need for cognitive therapy to manage psychological stress in antenatal women.

Assessment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome using different scanning approaches for the ultrasonographic evaluation of portal vein blood flow and hepatic artery resistive index in hematopoietic stem cell transplant recipients.

Sinusoidal obstruction syndrome (SOS) is a fatal complication of hematopoietic stem cell transplantation (HSCT). Previously, we established a scoring system (Hokkaido ultrasound-based scoring system-10; HokUS-10) comprising 10 ultrasound parameters for SOS diagnosis. In HokUS-10, the portal vein time-averaged flow velocity (PV TAV) and hepatic artery resistive index (HA RI) are measured using subcostal scanning. However, measurement errors and delineation difficulties occur. Therefore, we aimed to prospectively evaluate PV TAV and HA RI measurements obtained via intercostal scanning as an alternative method to subcostal scanning and determine their cutoff values. HokUS-10 was administered before and after HSCT. PV TAV and HA RI were measured on subcostal and right intercostal scans. We performed 366 scans on 74 patients. The median value (range) of PV TAV in the main and right portal veins was 15.0cm/s (2.2-49.6cm/s) and 10.5cm/s (1.6-22.0cm/s), respectively. A low correlation was observed between the two values (r = 0.39, p < 0.01). The highest diagnostic value of the right portal vein was less than 8.0cm/s. The median value (range) of HA RI in the proper and right hepatic arteries was 0.72 (0.52-1.00) and 0.70 (0.51-1.00), respectively. A strong correlation was observed between the two values (r = 0.65, p < 0.01). The highest diagnostic value of the right HA RI was 0.72 or higher. Quantitative measurement of PV TAV and HA RI using intercostal scanning can be appropriately performed as an alternative method to using subcostal scanning.

Update on the hemodynamic significance of stenotic lesion of the extracranial carotid arteries according to ultrasonic examination of the internal jugular vein

Aim. To study changes in the size and linear velocities of the blood flow of internal jugular veins in patients with high degree stenosis of the extracranial carotid artery.Methods. The study included 28 patients: 14 patients with high degree stenoses of the internal carotid arteries (70% and more by NASCET criteria) constituted group 1, 14 patients with “small” stenoses of the ICA (less than 30%) – group 2. The state of blood flow in the extracranial sections of the main arteries of the head were evaluated using ultrasound.Results. When studying the features of venous blood flow, the following was found: in the group with unilateral hemodynamically significant stenosis, in contrast to the group of patients with “small” stenoses, the venous pressure measured on the arm was statistically significantly lower, and therefore the calculated central venous pressure, while the linear velocities of the peaks S and T were statistically significantly higher by 1 the group on the side of hemodynamically significant stenosis. On the side of contralateral stenosis in group 1, there was statistically significantly less area of VAV, and the ratio S1/S2, than in patients of group 2. Intra-group analysis revealed a statistically significant difference in almost all indicators in patients with hemodynamically significant stenosis compared with the contralateral side: the diameters of the vein and its area were larger, and the linear rates of the A, S and T peaks were higher. Whereas there were no statistically significant differences in the group of “small” stenoses.Conclusion. Changes in venous blood flow in the jugular veins are interrelated with the development of high degree carotid stenosis and have diagnostic significance, can be used as an additional sign of the hemodynamic significance of carotid stenosis.

Full-Right Full-Left Split Liver Transplantation for Two Adult Recipients: A Single-Center Experience in China.

The most effective treatment for end-stage liver diseases is liver transplantation, which is impeded by the shortage of donor livers. Split liver transplantation (SLT) is important for addressing the donor liver shortage. However, full-right full-left SLT for two adult recipients is globally rarely conducted. This study aimed to investigate the clinical outcomes of this technique. We retrospectively analyzed the clinical data of 22 recipients who underwent full-right full-left SLT at Shulan (Hangzhou) Hospital between January, 2021 and September, 2022. The graft-to-recipient weight ratio (GRWR), cold ischemia time, operation time, length of the anhepatic phase, intraoperative blood loss, and red blood cell transfusion amount were all analyzed. The differences in liver function recovery after transplantation were compared between the left and right hemiliver groups. The postoperative complications and prognosis of the recipients were also analyzed. The livers of 11 donors were transplanted into 22 adult recipients. The GRWR ranged from 1.16-1.65%, the cold ischemia time was 282.86 ± 134.87 min, the operation time was 371.32 ± 75.36 min, the anhepatic phase lasted 60.73 ± 19.00 min, the intraoperative blood loss was 759.09 ± 316.84 mL, and the red blood cell transfusion amount was 695.45 ± 393.67 mL. No significant difference in the levels of liver function markers, total bilirubin, aspartate aminotransferase, or alanine aminotransferase between left and right hemiliver groups at 1, 3, 5, 7, 14, and 28 d postoperatively was observed (both p > 0.05). One recipient developed bile leakage 10 d after transplantation, which improved with endoscopic retrograde cholangiopancreatography-guided nasobiliary drainage and stent placement. Another developed portal vein thrombosis 12 d after transplantation and underwent portal vein thrombectomy and stenting to restore portal vein blood flow. A color Doppler ultrasound performed 2 d after transplantation revealed hepatic artery thrombosis in one patient, and thrombolytic therapy was administered to restore hepatic artery blood flow. The liver function of other patients recovered quickly after transplantation. Full-right full-left SLT for two adult patients is an efficient way to increase the donor pool. It is safe and feasible with careful donor and recipient selection. Transplant hospitals with highly experienced surgeons in SLT are recommended to promote using full-right full-left SLT for two adult recipients.

Udder Ultrasonography of Dairy Cows: Investigating the Relationship between Echotexture, Blood Flow, Somatic Cell Count and Milk Yield during Dry Period and Lactation.

Udder health of dairy cows is related to their productivity and welfare. The period from dry-off to calving and early lactation is crucial. Ultrasonography is a useful and practical tool for the examination of the mammary parenchyma and blood flow. This observational study investigated the relationship between udder echotexture features, blood flow volume (BFVol) in the milk vein, milk somatic cell count (SCC) and daily milk yield (DMY) from late lactation, throughout the dry period and consecutive early lactation. Seventeen repeated measurements were performed on twenty-one Holstein cows. The udder parenchyma was examined with B-mode ultrasonography. Udder echotexture was studied using 15 features: Numerical Pixel Value (NPV), Pixel Standard Deviation (PSD), Skewness, Excess, Contrast, Homogeneity, Correlation, Entropy, Run Percentage, Long-Run Emphasis, Grey Value Distribution, Runlength Distribution, Gradient Mean Value, Gradient Variance and Percentage of Non-zero Gradients. Blood flow in the milk vein was examined with spectral Doppler. Linear mixed-effects models were employed to investigate relationships between BFVol, udder echotexture features, SCC and DMY throughout the study period. Our models showed that a 1 kg increase in DMY was associated with a significant increase of 0.25 L/min in the expected BFVol and that a 1,000,000-cells/mL increase in SCC was associated with a significant BFVol decrease of 0.49 L/min, keeping all other variables constant. Multivariable models showed significant associations between DMY and NPV, between PSD and Long-Run Emphasis, and between SCC and NPV, PSD, Gradient Mean Value, Homogeneity, Gradient Variance and Entropy. In conclusion, udder echotexture and BFVol in the milk vein are related to SCC and milk yield. Ultrasonography can be used for the comprehensive assessment of udder health in support of precision dairy farming.

PROTOCOLO DE BIOMAGNETISMO MEDICINAL NO TRATAMENTO DE INSUFICIÊNCIA VENOSA CRÔNICA DE MEMBROS INFERIORES

Magnetic therapies have been the focus of studies due the positive results observed in clinical practice. The application of Static Magnetic Fields affects human body cells. This interaction has shown good results in the treatment of various symptoms and diseases. Based on studies by Dr. Richard Broeringmeyer, Dr. Isaac Goiz Durán developed a new therapy: Medicinal Biomagnetism (BM). Changes in body flows, such as the vascular change, is the base of one of Dr. Goiz findings and can be influenced by Biomagnetic Pairs that can sustain pathogenic microorganisms or generate tissue changes that can hinder venous return. Chronic Venous Insufficiency (CVI) is the deficiency of blood flow in the deep veins of the lower limbs, resulting from dysfunctions of venous return from the limbs to the heart, causing blood reflux, venous hypertension sustained by blood accumulation in the deep veins. BM is a non-invasive, low-cost, painless, easy-to-apply and minimally contraindicated complementary practice, which aims the prevention of various pathologies, including CVI, as an alternative with great therapeutic potential. The purpose of this bibliographical review study of an exploratory and qualitative analytical method is to present a BM protocol that can be applied to assist in CVI`s treatment. As a result of this study, the Treatment Protocol for Lower Limbs Blood Flow (FSMI) is presented. It concludes that this might help in CVI`s treatment, signs and symptoms, facilitating venous return, deserving to be measured in larger studies.

Effect of stent treatment on hemodynamics in iliac vein compression syndrome with collateral vein.

Iliac vein compression syndrome (IVCS) leads to blood flow obstruction in the lower extremities and is usually treated with stents, but stenting may worsen the hemodynamics and increase the risk of thrombosis in the iliac vein. The present work evaluates the advantages and disadvantages of the stent on IVCS with a collateral vein. The computational fluid dynamics method is adopted to analyze the preoperative and postoperative flow fields in a typical IVCS. The geometric models of the iliac vein are constructed from medical imaging data. The porous model is used to simulate the flow obstruction in IVCS. The preoperative and postoperative hemodynamic characteristics in the iliac vein are obtained, e.g., the pressure gradient at two ends of the compressive region and the wall shear stress. It is found that the stenting restores the blood flow in the left iliac vein. Impacts of the stent are classified into short-term and long-term effects. The short-term effects are beneficial in relieving IVCS, i.e., shortening the blood stasis and reducing the pressure gradient. The long-term effects increase the risk of thrombosis in the stent, i.e., enlarging wall shear stress due to a large corner and a diameter constriction in the distal vessel, and suggests the need to develop a venous stent for IVCS.

Umbilical Vein Blood Flow in Uncomplicated Pregnancies: Systematic Review of Available Reference Charts and Comparison with a New Cohort.

The objectives of the study were (1) to perform a systematic review of the available umbilical vein blood flow volume (UV-Q) reference ranges in uncomplicated pregnancies; and (2) to compare the findings of the systematic review with UV-Q values obtained from a local cohort. Available literature in the English language on this topic was identified following the PRISMA guidelines. Selected original articles were further grouped based on the UV sampling sites and the formulae used to compute UV-Q. The 50th percentiles, the means, or the best-fitting curves were derived from the formulae or the reported tables presented by authors. A prospective observational study of uncomplicated singleton pregnancies from 20+0 to 40+6 weeks of gestation was conducted to compare UV-Q with the results of this systematic review. Fifteen sets of data (fourteen sets belonging to manuscripts identified by the research strategy and one obtained from our cohort) were compared. Overall, there was a substantial heterogeneity among the reported UV-Q central values, although when using the same sampling methodology and formulae, the values overlap. Our data suggest that when adhering to the same methodology, the UV-Q assessment is accurate and reproducible, thus encouraging further investigation on the possible clinical applications of this measurement in clinical practice.

Improving blood flow in occluded veins to reduce anti-vascular endothelial growth factor injections for branch retinal vein occlusion

PurposeTo assess the relationship between improving blood flow via arteriovenous (AV) sheathotomy without vitrectomy and the total number of anti-vascular endothelial growth factor injections (VEGF) required to treat branch retinal vein occlusion (BRVO). MethodsIn this prospective, clinical case series, 16 eyes of 16 patients at the Toho University Sakura Medical Center with best-corrected visual acuity (BCVA) of 20/40 or worse due to macular edema associated with BRVO were analyzed for 12 months. AV sheathotomy was performed without vitrectomy for all cases. On the second day after surgery, anti-VEGF was injected into the operated eye. During the 12-month follow-up after surgery, pro re nata injections were administered when changes in foveal exudation and BCVA were evident. The blood flow of the occluded vein was assessed before and after AV sheathotomy during the operation using laser speckle flowgraphy. The total number of anti-VEGF injections, central retinal thickness (CRT), and BCVA 12 months after surgery were examined. ResultsThe changes in CRT and BCVA from baseline to month 12 were statistically significant (P < 0.01). No additional anti-VEGF injections were required for nine of 16 eyes (56.3%) during the 12 months. The total number of anti-VEGF injections for 12 months correlated with the change rate of blood flow in an occluded vein before and after AV sheathotomy (r = −2.816, P = 0.022). Conclusions and ImportanceImproved blood flow in occluded vein may reduce the need for anti-VEGF injections in BRVO.

The effect of immediate postoperative increase in blood flow velocity in predicting maturation of arteriovenous fistula for dialysis

Background Doppler ultrasonography is the main imaging modality for hemodialysis arteriovenous fistula (AVF) as it is safe, accurate, and noninvasive. Published literature related to the utility of early postoperative ultrasound in predicting AVF maturation is scarce. With the KDOQI guidelines recommending an AVF first catheter last approach, the quest to increase AVF maturation is of utmost importance. This study aims at measuring blood flow immediately postoperatively and assessing its predictive role in AVF maturation. Methods We correlated the ultrasound parameters with maturation in newly created AVFs measured preoperatively, immediately postoperatively, 6 weeks, and 3, 6, and12 months postoperatively. Both demographics and vascular parameters were compared between the group of patients whose AVFs successfully maturated and those whose AVFs did not. Primary endpoint was AVF maturation; secondary endpoints included patency, functional success, and predictive value of increased vein blood flow on fistula patency. Results A total of 50 procedures were performed; the mean age was 52.12 years (±6.58). The overall technical success rate was 86% (43) and 39 (90.7%) of them were functionally mature according to KDOQI guidelines for maturation. Primary patency was 93.02%, 92.7%, and 88.89%; and the primary-assisted patency was 97.7%, 95.12%, and 91.67% at 3, 6, and 12 months, respectively. Receiver-operated curve (ROC) showed a cutoff value of 322.8 ml/min increase in blood flow above which the AVF is more likely to become mature. Binary logistic regression showed that arterial depth greater than 3.92 mm, arterial flow velocity greater than 88 ml/min, preoperative average vein diameter of greater than 2.5 mm, arterial flow velocity of greater than 73 ml/min immediately postoperatively, and average vein diameter of greater than 3.94 mm immediately postoperatively were significant predictors of successful maturation at 6 weeks postoperatively (P values 0.001, &lt;0.0001, &lt;0.0001, &lt;0.0001, and &lt;0.0001, respectively). Conclusion Immediately postoperative flow measurement is a reliable parameter that can be used to predict successful fistula maturation, especially if flow velocities exceed 326.15 ml/min.

Use of physical rehabilitation to improve venous blood flow in varicose veins

Statistics, symptoms, complications of varicose veins of the lower extremities were studied. According to the data of the scientific and methodical literature, the influence of the means of physical rehabilitation of patients on the improvement of venous blood flow was determined, and the most effective methods and means were selected. It has been shown that varicose veins (varicose veins) of the lower extremities are the most common among all vascular diseases. The World Health Organization included it in the list of "diseases of civilization", because according to statistics, in developed countries, varicose veins are observed in 25-34% of women and 10-20% of men. In Europe, an average of 22.23 million people suffer from varicose veins, in the USA - 98.4 million, and in Ukraine - 12.57 million people. In recent years, the disease has become younger and occurs in patients aged 12-16 years. In addition to aesthetic problems, the disease often leads to disability and death (its fatal complication is thromboembolism of the branches of the pulmonary artery). The main part of the work is devoted to the study of the influence of methods and means of physical rehabilitation, based on their physical and compressive action, with the aim of rehabilitation, preventing the progression of varicose veins and improving the morphofunctional state of patients at various stages of the disease. It is shown that the rehabilitation program should include recommendations for modifying the patient's lifestyle, wearing compression stockings to prevent dilatation of the veins of the lower extremities, to restore the "vascular pump" of the calf muscle, an individually developed walking program is offered, and kinesio taping is used to strengthen regional blood circulation.

Administration of a new nano delivery system coated with Tirofiban to prevent early thrombosis of vein graft.

To verify the administration of a new nano delivery system coated with Tirofiban on preventing early thrombosis in vein graft. Forty New Zealand white rabbits were randomly divided into five groups with eight rabbits in each group. The rabbits of all groups underwent jugular vein transplantation, except group I with only neck opening and closing operation. Vein grafts of group II were preprocessed by intravenous injection of normal saline; group III were preprocessed by tirofiban alone; group IV were preprocessed by unloaded nanoparticles of PLGA-PEG; group V were preprocessed by PLGA-PEG coated with tirofiban. Coagulation and platelet function of peripheral and vein graft blood were detected at 1, 2, 4, 12h and 1, 3, 7, 10, 14 days after operation. Patency rate of vein graft and blood flow index were measured by vascular ultrasound at third, seventh, 10th, and 14th days after operation; two rabbits in each group were randomly sacrificed at the corresponding time of detection. Pathological differences of vein grafts were observed by HE stainin. The patency rate of vein grafts in group V was significantly higher than that in group II to IV. The platelet and platelet aggregation rate in group V were inhibited in vein graft blood significantly. The post-operative PT and APTT in vein graft blood in group V were increased obviously while the FBG, D-dimer and FDP were significantly inhibited. Except group I, the lumen loss rate of vein grafts in group V was significantly lower than that in other groups, and vein graft blood in group V had a significant lower expression of platelet P-selectin and GP IIb/IIIa receptor than that in other groups. This study proves that PEG-PLGA coated with tirofiban can effectively prevent early vein graft stenosis from thrombosis by inhibition of platelet function, coagulation function.

Pulmonary Vein Sign on Computed Tomography Pulmonary Angiography in Proximal and Distal Chronic Thromboembolic Pulmonary Hypertension With Hemodynamic Correlation.

Pulmonary vein sign (PVS) indicates abnormal pulmonary venous flow on computed tomography pulmonary angiography (CTPA) is a frequent finding in proximal chronic thromboembolic pulmonary hypertension (CTEPH). PVS's occurrence in distal CTEPH and correlation to disease severity is unknown. Using right heart catheterization data, we evaluated the relationship between PVS and CTEPH disease distribution and severity. A total of 93 consecutive CTEPH cases with both CTPA and right heart catheterization were identified in this retrospective multi-institutional study. After excluding 17 cases with suboptimal CTPA, there were 52 proximal and 24 distal CTEPH cases. Blood flow in the major pulmonary veins was graded qualitatively. Subgroup analysis of PVS was performed in 38 proximal CTEPH cases before and after pulmonary endarterectomy. PVS was more frequent in proximal (79%) than distal CTEPH (29%) ( P <0.001). No significant difference was noted in invasive mean pulmonary artery pressure (46±11 and 41±12mmHg) or pulmonary vascular resistance (9.4±4.5 and 8.4±4.8 WU) between the 2 groups. In the subgroup analysis, PVS was present in 29/38 patients (76%) before surgery. Postoperatively, 33/38 cases (87%, P <0.001) had normal venous flow (mean pulmonary artery pressure 46±11 and 25; pulmonary vascular resistance 9.2±4.3 and 2.6 WU preop and postop, respectively). PVS is a common feature in proximal but infrequent findings in distal CTEPH. PVS does not correlate with hemodynamic severity. PVS resolution was seen in the majority of patients following successful endarterectomy.

Placental and Doppler ultrasound findings in pregnant women with SARS-CoV-2 infection

Several viral infections cause changes in the placenta. Cytomegalovirus, herpes viruses, and HIV cause increased placental thickness; Zika virus induces focal regions of necrosis; parvovirus B19 causes a structural injury. Umbilical flow can be considered a direct measurement of vascular placental function. This study aimed to compare placental ultrasound and umbilical Doppler findings in pregnant women who tested positive or negative for SARS-CoV-2. Our work aimed to confirm the suspicion of placental infection and the consequence in fetal physiopathology. Fifty-seven pregnant women who tested positive for SARS-CoV-2 at the time of or 1 month before the ultrasound scan were evaluated. Cases included 9 first trimester, 16 second trimester, and 32 third trimester ultrasound scans. For comparison, 110 pregnant women (controls) were evaluated. They included 19 women in their first trimester, 43 in their second trimester, and 48 in the third trimester. Controls were asymptomatic and tested negative for SARS-CoV-2 infection in the last 72 hours before the ultrasound scan. Fetal biometry, placental thickness, placental lakes and Doppler umbilical vein parameters, including venous cross-sectional area (mean transverse diameter and radius of umbilical vein, mean velocity of umbilical vein), and umbilical vein blood flow were evaluated. Placental thickness (in millimeter) was significantly higher in the group of pregnant women with SARS-CoV-2 infection (53.82 [10-115]) than in the control group (33.82 [12-66]; P<.001) in their second and third trimesters. The frequency of >4 placental lakes was significantly higher in the group of pregnant women with SARS-CoV-2 infection (28/57 [50.91%]) than in the control (7/110 [6.36]; P<.001) in all 3 trimesters. The mean velocity of umbilical vein was significantly higher in the group of pregnant women with SARS-CoV-2 infection (12.45 [5.73-21]) than in the control group (10.81 [6.31-18.80]; P=.001) in all 3 trimesters. Umbilical vein blood flow (in milliliter per minute) was significantly higher in the group of pregnant women with SARS-CoV-2 infection (389.9 [6.52-1496.1]) than in the control group (305.05 [3.11-1441]; P=.05) in all 3 trimesters. Significant differences in placental and venous Doppler ultrasound were documented. Placental thickness, placental venous lakes, mean velocity of umbilical vein, and umbilical vein flow were significantly higher in the group of pregnant women with SARS-CoV-2 infection in all 3 trimesters.

The abnormal umbilical venous-arterial index in the second half of pregnancy is associated with fetal outcome: A retrospective cross-sectional study.

This study aims to observe the changes of the umbilical venous-arterial index (VAI) and investigate its predictive power for fetal outcome during the second half of pregnancy. Fetuses with gestational age (GA) at 24-39 weeks were collected. According to the outcome score, neonates with outcome scores of 0, 1, or 2 were assigned to the control group, whereas those with scores of 3-12 were assigned to the compromised group. VAI was calculated as the ratio of normalized umbilical vein blood flow volume and umbilical artery pulsatility index. Regression analysis was performed to obtain the best-fitting curves between VAI and GA in the controls. Doppler parameters and perinatal outcomes were compared in both groups. Receiver operating characteristic analysis was used to assess the diagnostic performance of the VAI. A total of 833 (95%) fetuses had Doppler parameters and pregnancy outcomes documented. Compared with the controls, the VAI was significantly lower in the compromised group (83.2 vs. 184.8 ml/min/kg, p < 0.001). The sensitivity and specificity of VAI to predict compromised neonates were 95.15% (95% Cl, 89.14 to 97.91%) and 99.04% (95% CI: 98.03 to 99.53%), respectively at a cutoff value of 120 ml/min/kg. VAI presents better diagnostic performance than umbilical vein blood flow volume and umbilical artery pulsatility index. A cutoff value of 120 ml/min/kg might be used as the warning value for predicting the fetal outcome.