0D-1D coupling model and 3D fluid-structure interaction model based on coronary CT angiography for displaying hemodynamic characteristics of coronary artery stenosis

Objective To observe value of 0D-1D coupling model and 3D fluid-structure interaction(FSI)model based on coronary CT angiography(CCTA)for displaying hemodynamic characteristics of coronary artery stenosis.Methods Based on CCTA data of the stenosed left anterior descending branch(LAD)in a patient with coronary heart disease,an 0D-1D coupling model and 3D FSI model were built,respectively.Then hemodynamic characteristic indexes,including the pressure,flow velocity and wall shear stress(WSS)were obtained in every 0.01 s during 1 s at 5 sampling points(i.e.sampling point 1—5)using these 2 models,respectively,and the consistencies of the results between models were evaluated with Spearman correlation coefficient r s.Results The time consuming for construction of 0D-1D coupling model and 3D FSI model was 0.033 min and 704 min,respectively.Both models showed basically distribution of the pressure,flow velocity and WSS of the stenosed LAD.For more details,the pressure at the stenosed segment of LAD and the proximal segment of stenosis were both higher,which gradually decreased at the distal segment of stenosis,and the flow velocity at the proximal segment of stenosis was in a relatively slow and uniform condition,with significantly increased flow velocity and WSS at the stenosed segment.Compared with 3D FSI model,0D-1D vascular coupling model was relatively unrefined and lack of distal flow lines when displaying blood flow velocity.For sampling point 2 at the stenosed segment of LAD,no significant consistency for pressure between 2 models was found(P=0.118),but strong consistency for the flow velocity and WSS(r s=0.730,0.807,both P<0.05).The consistencies of pressure,flow velocity and WSS between 2 models at the proximal and distal segment of stenosis,i.e.1,3—5 sampling points were week to moderate(r s=0.237—0.669,all P<0.05).Conclusion 0D-1D coupling model exhibited outstanding computational efficiency and might provide relatively reasonable results,while 3D FSI model showed higher accuracy for details and streamline when simulating LAD stenosis.

Effect of Dexmedetomidine on Maintaining Perioperative Hemodynamic Stability in Elderly Patients:A Systematic Review and Meta-analysis

Objective Dexmedetomidine is a highly selective alpha-2 adrenergic receptor agonist with sedative and analgesic properties but without respiratory depression effect and has been widely used in perioperative anesthesia.Here we performed a systematic review and meta-analysis to evaluate the effect of dexmedetomidine on maintaining perioperative hemodynamic stability in elderly patients.Methods PubMed,Web of Science,the Cochrane Library,China National Knowledge Infrastructure(CNKI),and Wanfang Data were searched for randomized-controlled trials(RCTs)on the application of dexmedetomidine in maintaining perioperative hemodynamic stability in elderly patients from their inception to September,2021.The standardized mean differences(SMD)with 95%confidence interval(CI)were employed to analyze the data.The random-effect model was used for the potential clinical inconsistency.Results A total of 12 RCTs with 833 elderly patients(dexmedetomidine group,546 patients;control group,287 patients)were included.There was no significant increase in perioperative heart rate(HR),mean arterial pressure(MAP),and diastolic blood pressure(DBP)in the dexmedetomidine group before and during the operation.In addition,the variations of hemodynamic indexes including HR,MAP,SBP(systolic blood pressure),and DBP were significantly lower in the dexmedetomidine group compared with the control group(HR:SMD=-0.87,95%CI:-1.13 to-0.62;MAP:SMD=-1.12,95%CI:-1.60 to-0.63;SBP:SMD=-1.27,95%CI:-2.26 to-0.27;DBP:SMD=-0.96,95%CI:-1.33 to-0.59).Subgroup analysis found that with the prolongation of 1.0μg/kg dexmedetomidine infusion,the patient’s heart rate declined in a time-dependent way.Conclusion Dexmedetomidine provides more stable hemodynamics during perioperative period in elderly patients.However,further well-conducted trials are required to assess the effective and safer doses of dexmedetomidine in elderly patients.

Spatiotemporal hemodynamic monitoring via configurable skin-like microfiber Bragg grating group

Systemic blood circulation is one of life activity’s most important physiological functions.Continuous noninvasive hemodynamicmonitoring is essential for the management of cardiovascular status.However,it is difficult to achieve systemichemodynamic monitoring with the daily use of current devices due to the lack of multichannel and time-synchronized operationcapability over the whole body.Here,we utilize a soft microfiber Bragg grating group to monitor spatiotemporalhemodynamics by taking advantage of the high sensitivity,electromagnetic immunity,and great temporal synchronizationbetween multiple remote sensor nodes.A continuous systemic hemodynamic measurement technique is developedusing all-mechanical physiological signals,such as ballistocardiogram signals and pulse waves,to illustrate the actualmechanical process of blood circulation.Multiple hemodynamic parameters,such as systemic pulse transit time,heartrate,blood pressure,and peripheral resistance,are monitored using skin-like microfiber Bragg grating patches conformallyattached at different body locations.Relying on the soft microfiber Bragg grating group,the spatiotemporal hemodynamicmonitoring technique opens up new possibilities in clinical medical diagnosis and daily health management.

One in four patients with gastrointestinal bleeding develops shock or hemodynamic instability:A systematic review and meta-analysis

BACKGROUND Hemodynamic instability and shock are associated with untoward outcomes in gastrointestinal bleeding.However,there are no studies in the existing literature on the proportion of patients who developed these outcomes after gastrointestinal bleeding.AIM To determine the pooled event rates in the available literature and specify them based on the bleeding source.METHODS The protocol was registered on PROSPERO in advance(CRD42021283258).A systematic search was performed in three databases(PubMed,EMBASE,and CENTRAL)on 14^(th) October 2021.Pooled proportions with 95%CI were calculated with a random-effects model.A subgroup analysis was carried out based on the time of assessment(on admission or during hospital stay).Heterogeneity was assessed by Higgins and Thompson’s I^(2) statistics.The Joanna Briggs Institute Prevalence Critical Appraisal Tool was used for the risk of bias assessment.The Reference Citation Analysis(https://www.referencecitationanalysis.com/)tool was applied to obtain the latest highlight articles.RESULTS We identified 11589 records,of which 220 studies were eligible for data extraction.The overall proportion of shock and hemodynamic instability in general gastrointestinal bleeding patients was 0.25(95%CI:0.17-0.36,I^(2)=100%).In non-variceal bleeding,the proportion was 0.22(95%CI:0.14-0.31,I^(2)=100%),whereas it was 0.25(95%CI:0.19-0.32,I^(2)=100%)in variceal bleeding.The proportion of patients with colonic diverticular bleeding who developed shock or hemodynamic instability was 0.12(95%CI:0.06-0.22,I^(2)=90%).The risk of bias was low,and heterogeneity was high in all analyses.CONCLUSION One in five,one in four,and one in eight patients develops shock or hemodynamic instability on admission or during hospitalization in the case of non-variceal,variceal,and colonic diverticular bleeding,respectively.

Hemodynamic Profiling Using a Cardiac Index–Systemic Vascular Resistance Plot in Patients with Fontan Circulation

Background: Elevated Fontan pressure (FP) alone cannot fully predict clinical outcomes. We hypothesized thathemodynamic profiling using a cardiac index (CI)-systemic vascular resistance (SVR) plot could characterize clinicalfeatures and predict the prognosis of post-Fontan patients. Methods: We included post-Fontan patients whounderwent cardiac catheterization at age < 10 years. Patients were classified into four categories: A, CI ≥ 3, SVRindex (SVRI) ≥ 20;B, CI < 3, SVRI ≥ 20;C, CI ≥ 3, SVRI < 20;and D, CI < 3, SVRI < 20. The primary outcome wasfreedom from the combined endpoint: new onset of protein-losing enteropathy or plastic bronchitis, heart transplant,and death. Clinical and hemodynamic variables and freedom from the endpoint were compared betweenthe hemodynamic categories and outcome predictors were evaluated. Results: Eighty-three patients wereincluded. Median follow-up was 5.3 years. Category A/B/C/D consisted of 4/15/53/11 patients, respectively. Allthe patients in category A were New York Heart Association I/II and had a significantly lower pulmonary vascularresistance index (PVRI). Patients in category C had lower pulmonary/systemic blood flow. Patients in category Dhad a higher PVRI and had the poorest freedom from the endpoint (44% at 5 years). Elevated FP and category Dwere outcome predictors. Conclusions: CI-SVR plots was a novel adjunctive method for Fontan hemodynamicprofiling.

Preliminary Evaluation of Hemodynamic Effects of Fontan Palliation on Renal Artery Using Computational Fluid Dynamics

Background:The assessment of renal function is important to the prognosis of patients needing Fontan palliation due to the reconstructed compromised circulation.To know the relationship between the kidney perfusion and hemodynamic characteristics during surgical design could reduce the risk of acute kidney injury(AKI)and the postoperative complications.However,the issue is still unsolved because the current clinical evaluation methods are unable to predict the hemodynamic changes in renal artery(RA).Methods:We reconstructed a three-dimensional(3D)vascular model of a patient requiring Fontan palliation.The technique of computational fluid dynamics(CFD)was utilized to explore the changes of RA hemodynamics under different possible blood flow rates.The relationship between the kidney perfusion and hemodynamic characteristics was investigated.Results:The calculated results indicated the declined tendency of the pressure and pressure drop as the flow rate decreased.When the flow rate decreased to two-thirds of its baseline,both the pressure of left renal artery(LRA)and the pressure of right renal artery(RRA)dipped below 50%,and the pressure of RRA fell more quickly than that of LRA.Uneven distribution of WSS was observed on the trunk of RA,and the lowest WSS was found at the distal of RA.The average WSS in RA dropped to around 50%as the flow rate reached one-third of its baseline.Conclusions:As a promising approach,CFD can be utilized to quantitatively evaluate the hemodynamic characteristics of RA and contribute to offsetting the drawbacks of clinical assessments of renal function,to help realize better prognosis for the patients with Fontan palliation.

Effects of remifentanil combined with propofol on hemodynamics and oxidative stress in patients undergoing resection of rectal carcinoma

BACKGROUND Rectal carcinoma(RC)treatment primarily involves laparoscopic surgery,which may induce significant hemodynamic changes and weaken immune function.Certain anesthetic approaches using opioid drugs(including remifentanil and sufentanil)pose risks,such as hypotension.AIM To determine the effects of remifentanil combined with propofol on hemodynamics and oxidative stress in patients undergoing RC resection.METHODS A total of 211 patients one hundred and four patients with RC treated at the First Affiliated Hospital of Dalian Medical University between November 2018 and November 2022 were retrospectively analyzed.Among them,the remifentanil group included 45 patients receiving remifentanil with propofol anesthesia and the sufentanil group included 59 patients receiving sufentanil with propofol anesthesia.Changes in the hemodynamic index,oxidative stress index,general data,consumption of remifentanil,and use of vasoactive drugs were compared.The incidences of adverse reactions were calculated.RESULTS The two groups did not significantly differ in terms of operation,anesthesia,and extubation times(P>0.05).At 1 min after intubation,the sufentanil group showed a notably higher heart rate,systolic blood pressure(SBP),diastolic blood pressure,and mean arterial pressure(MAP)compared with the remifentanil group(P<0.05),whereas the sufentanil group showed a notably higher SBP and MAP compared with the remifentanil group at 5 min after pneumoperitoneum(P<0.05).Thirty minutes after surgery,the remifentanil group showed significantly lower plasma cortisol,noradrenaline,and glucose levels than the sufentanil group(P<0.001).The remifentanil group consumed significantly less remifentanil than the sufentanil group(P<0.05),and the adoption frequency of ephedrine was lower in the remifentanil group than that in the sufentanil group(P<0.05).The incidence of hypotension was notably higher in the sufentanil group than that in the remifentanil group(P<0.05).CONCLUSION Remifentanil combined with propofol can improve hemodynamics and relieve oxidative stress in patients undergoing RC resection.

Research progress on the influence of local hemodynamics on carotid atherosclerosis

The reasons for the formation of atherosclerosis are diverse and complex,and atherosclerosis as a kind of systemic disease has the characteristics of focal selectivity,which occurs in the carotid bifurcation.The feature enables a large number of studies have found that the severe local hemodynamic characteristics has a great influence to the occurrence of this disease.This paper briefly reviews the related research on the local hemodynamics of carotid bifurcation.The relevant parameters of local hemodynamics were sorted out and summarized,and the effects of wall shear force and its derived parameters on the generation,progression and rupture of carotid atherosclerosis and their clinical applications were reviewed,in order to provide mechanical information for the early warning of carotid plaque rupture.At the same time,this paper describes the transformation of local hemodynamics research in the clinical application of carotid atherosclerosis disease,in order to provide personalized selection and basis for the clinical treatment of this disease.

Clinical efficacy of total laparoscopic splenectomy for portal hypertension and its influence on hepatic hemodynamics and liver function

BACKGROUND The liver hemodynamic changes caused by portal hypertension(PH)are closely related to various complications such as gastroesophageal varices and portosystemic shunts,which may lead to adverse clinical outcomes in these patients,so it is of great clinical significance to find treatment strategies with favorable clinical efficacy and low risk of complications.AIM To study the clinical efficacy of total laparoscopic splenectomy(TLS)for PH and its influence on hepatic hemodynamics and liver function.METHODS Among the 199 PH patients selected from October 2016 to October 2020,100 patients[observation group(OG)]were treated with TLS,while the remaining 99[reference group(RG)]were treated with open splenectomy(OS).We observed and compared the clinical efficacy,operation indexes[operative time(OT)and intraoperative bleeding volume],safety(intraperitoneal hemorrhage,ascitic fluid infection,eating disorders,liver insufficiency,and perioperative death),hepatic hemodynamics(diameter,velocity,and flow volume of the portal vein system),and liver function[serum alanine aminotransferase(ALT),serum aspartate aminotransferase(AST),and serum total bilirubin(TBil)]of the two groups.RESULTS The OT was significantly longer and intraoperative bleeding volume was significantly lesser in the OG than in the RG.Additionally,the overall response rate,postoperative complications rate,and liver function indexes(ALT,AST,and TBil)did not differ significantly between the OG and RG.The hepatic hemodynamics statistics showed that the pre-and postoperative blood vessel diameters in the two cohorts did not differ statistically.Although the postoperative blood velocity and flow volume reduced significantly when compared with the preoperative values,there were no significant inter-group differences.CONCLUSION TLS contributes to comparable clinical efficacy,safety,hepatic hemodynamics,and liver function as those of OS in treating PH,with a longer OT but lesser intraoperative blood loss.

Hemodynamic Fetal Response to Maternal Isometric Exercise in Pregnant Patients with Hypertension

Objective: to evaluate the maternal-fetal hemodynamic response with Doppler in pregnant women with chronic arterial hypertension and preeclampsia submitted to controlled isometric activity. Methods: experimental study comparing 50 healthy and 26 hypertensive and 24 preeclamptic pregnant women, from 26 to 36 weeks of gestational age, submitted to isometric contraction with handgrip dynamometer. Maternal hemodynamic parameters (systolic and diastolic blood pressure;heart rate;uterine arteries Doppler) and fetal (heart rate;umbilical artery, middle cerebral and venous duct Doppler) were evaluated before, during and post-isometry. Results: in preeclampsia were observed higher values of blood pressure and uterine artery indexes in all times;middle cerebral artery indexes in the pre and post-isometry;and of maternal heart rate post-isometry. In hypertensive women, systolic blood pressure is increased all the times, with indexes of the right uterine and middle cerebral arteries higher in pre-isometry;middle cerebral and umbilical arteries greater during isometry;and maternal heart rate and umbilical artery indexes bigger after isometry. Conclusion: blood pressure is higher in preeclamptic and hypertension women. The right uterine artery has more resistance in preeclampsia, with a significant decrease in pre to isometry in hypertensive and preeclamptic women;and increased in contraction to post-isometry in healthy and hypertensive women. The left uterine artery increases resistance post-isometry in all groups. The fetal hemodynamic parameters did not show significant differences when comparing the before, during and post-isometry.

Hemodynamic Fetal Response to Maternal Isometric Exercise in Pregnant Patients with Diabetes

Background: Studies on physical activity during pregnancy and its impact on mother and fetus are still limited. International protocols consider only aerobic exercise and fail to provide information about other modalities such as isometric exercise. Isometric exercise promotes cardiorespiratory resistance and muscle strengthening, but it is rarely tested on pregnant women because it increases maternal blood pressure and can subsequently affect placental circulation. Objectives: To assess the fetal response by use of Doppler study in diabetes pregnant women submitted to isometric exercise. Methods: A cross-sectional experimental study was conducted on 25 diabetes pregnant women with gestational age between 26 and 36 weeks. The patients were submitted to isometric handgrip, and data were collected from the mother (blood pressure, heart rate and Doppler velocimetry for the uterine arteries) and from the fetus (heart rate, Doppler velocimetry for the umbilical artery, middle cerebral artery and ductus venosus). All variables were collected before, during and after the isometric handgrip. Results: There was a significant reduction in the pulsatilityindex (average values pre 0.77 ± 0.30, trans 0.65 ± 0.22, and post 0.75 ± 0.22, with p = 0.001), resistance index (average values pre 0.49 ± 0.12, trans 0.44 ± 0.10, and post 0.48 ± 0.90, with p =

Effects of Continuous Non-Invasive Blood Pressure Monitoring on Intraoperative Hemodynamics and Postoperative Myocardial Injury in Craniotomy:Comparison Between Groups Based on Self-Control and Propensity Score Matching

Objective:To explore the effect of continuous non-invasive blood pressure monitoring on intraoperative hemodynamics and postoperative myocardial injury in craniotomy.Methods:120 cases of elective craniotomy were divided into the self-control group(continuous non-invasive blood pressure monitoring and intermittent cuff non-invasive blood pressure monitoring,CNAP group)and propensity score matching group(only intermittent cuff non-invasive blood pressure measurement in previous craniotomy,PSM group);Goal-directed hemodynamic management in CNAP group included heart rate(HR),blood pressure(BP),stroke volume(SV),stroke variability(SVV),and systemic vascular resistance index(SVRI).The main index is to compare the troponin level within 72 hours after operation between the CNAP group and the PSM group;The secondary indicators are the comparison of the hemodynamic conditions between the CNAP group and the PSM at 10 specific time points.Results:The incidence of postoperative myocardial injury in the CNAP group was significantly lower than that in the PSM group(12%vs.30%,P=0.01);in the CNAP group hypotensive episodes(6 vs.3,P=0.01),positive balance of fluid therapy(700 vs.500 mL,P<0.001),more use of vasoactive drugs(29 vs.18,P=0.04),more stable hemodynamics medical status(P=0.03)were recorded.Conclusion:The hemodynamic management strategy based on continuous non-invasive blood pressure monitoring can reduce the incidence of myocardial injury after elective craniotomy and maintain a more stable hemodynamic state.

Noninvasive Hemodynamic Monitoring for Heart Failure:A New Era of Heart Failure Management

Despite the development of noninvasive tools as echocardiography,right-sided heart catheterization remains an integral part of the cardiovascular evaluation.In the last decade,better understanding of the hemodynamic process before heart failure decompensation led to improvement of outpatient strategies to prevent it.Advances in implantable wireless technology now allow frequent and direct measurement of intracardiac fi lling pressures,which can be monitored by health care providers to help tailor therapy to reduce fi lling pressures and hospital readmission rates.

Effects of Captopril and Nadolol on Renal Hemodynamics in Patients with Essential Hypertension

The randomized single-blind study was designed to compare the effects of captopril Cap),and nadolol(And)on renal hemodynamics in 60 patients with essential hyperttnsion.They were divided into two groups at random.Cap was given in dosage of 37.5-75 mg/d per os and And 40-80 mg/d.The results show that both drugs increase the blood volume distributed to the kidneys from cardiac output(renal blood flow/cardiac output),Cap increasing 10% (P<0. 05) and And 8%(F<0.05) Renal vascular resistance(RVR)is lowered by the two drugs,13%(P<0. 05) by Cap and 11%(P<0.05) by And.These suggest that both drugs facilitate the maintenance of renal blood circulation in patients with essential hypeitension.being beneficial for long-term treatment of hypertension.

Effects of rh BNP after PCI on non-invasive hemodynamic in acute myocardial infarction patients with left heart failure

Objective: To investigate the effects of exogenous recombinant human brain natriuretic peptide(rh BNP) after primary percutaneous coronary intervention(PCI) on non-invasive hemodynamic in acute myocardial infarction patients with left ventricular failure. Methods: A number of 96 acute myocardial infarction patients accompanied with heart failure after PCI hospitalized in the People's Hospital of Sanya during February 2012 to October 2015 were selected. They were randomly divided into the therapy group(n = 50) and control group(n = 46). On the basis of routine treatment, patients in the therapy group were treated with intravenous rh BNP(1.5 μg/kg was intravenous injection with uniform speed of 3 min, followed by continuous infusion 0.007 5 μg/kg·min for 72 h), while the control group received conventional treatment. Bio Z-2011 non-invasive hemodynamic real-time monitoring system was used to monitor the hemodynamic parameters changes and the leves of plasma pro-BNP, serum creatinine, serum potassium, serum sodium and urine volume of each group before and after treating for 30 min, 1 h, 3 h, 6 h, 12 h, 24 h, 48 h, 72 h. Results: Patients in the therapy group showed no effect on heart rate, while after 30 min of intravenous injection of rh BNP, CO, CI, SV, and SI increased significantly and LVET and TFC reduced at the same time, which had certain effect on blood pressure(SBP/DBP). Compared with the control group, the therapy group showed a faster and more effective improvement on haemodynamics. Conclusions: Acute myocardial infarction patients complicated with left heart failure after primary PCI can significantly improve hemodynamics by treating with rh BNP.

Hemodynamic analysis of esophageal varices in patients with liver cirrhosis using color Doppler ultrasound

AIM： To study the portal hemodynamics and their relationship with the size of esophageal varices seen at endoscopy and to evaluate whether these Doppler ultrasound parameters might predict variceal bleeding in patients with liver cirrhosis and portal hypertension. METHODS： One hundred and twenty cirrhotic patients with esophageal varices but without any previous bleeding were enrolled in the prospective study. During a 2-year observation period, 52 patients who had at least one episode of acute esophageal variceal hemorrhage constituted the bleeding group, and the remaining 68 patients without any previous hemorrhage constituted the non-bleeding group. All patients underwent endoscopy before or after color Doppler-ultrasonic examination, and images were interpreted independently by two endoscopists. The control group consisted of 30 healthy subjects, matched to the patient group in age and gender. Measurements of diameter, flow direction and flow velocity in the left gastric vein （LGV） and the portal vein （PV） were done in all patients and controls using color Doppler unit. After baseline measurements, 30 min after oral administration of 75 g glucose in 225 mL, changes of the diameter, flow velocity and direction in the PV and LGV were examined in 60 patients with esophageal varices and 15 healthy controls. RESULTS： The PV and LGV were detected successfully in 115 （96%） and 105 （88%） of 120 cirrhotic patients, respectively, and in 27 （90%） and 21 （70%） of 30 healthy controls, respectively. Among the 120 cirrhotic patients, 37 had F1, 59 had F2, and 24 had F3 grade varices. Compared with the healthy controls, cirrhotic group had a significantly lower velocity in the PV, a significantly greater diameter of the PV and LGV, and a higher velocity in the LGV. In the cirrhotic group, no difference in portal flow velocity and diameter were observed between patients with or without esophageal variceal bleeding （EVB）. However, the diameter and blood flow velocity of the LGV were significantly higher for EVB （＋） group compared with EVB （-） group （P〈0.01）. Diameter of the LGV increased with enlarged size of varices. There were differences between F1 and F2, F1 and F3 varices, but no differences between F2 and F3 varices （P = 0.125）. However, variceal bleeding was more frequent in patients with a diameter of LGV 〉6 mm. The flow velocity in the LGV of healthy controls was 8.70＋1.91 cm/s （n = 21）. In patients with liver cirrhosis, it was 10.3＋2.1 cm/s （n = 12） when the flow was hepatopetal and 13.5＋2.3 cm/s （n = 87） when it was hepatofugal. As the size of varices enlarged, hepatofugal flow velocity increased （P〈0.01） and was significantly different between patients with F1 and F2 varices and between patients with F2 and F3 varices. Variceal bleeding was more frequent in patients with a hepatofugal flow velocity 〉15 cm/s （32 of 52 patients, 61.5%）. Within the bleeding group, the mean LGV blood flow velocity was 16.6＋2.62 cm/s. No correlation was observed between the portal blood flow velocity and EVB. In all healthy controls, the flow direction in the LGV was hepatopetal, toward the PV. In patients with F1 varices, flow direction was hepatopetal in 10 patients, to-and-fro state in 3 patients, and hepatofugal in the remaining 18. The flow was hepatofugal in 91% patients with F2 and all F3 varices. Changes in diameter of the PV and LGV were not significant before and after ingestion of glucose （PV： 1.41＋1.5 cm before and 1.46＋1.6 cm after; LGV： 0.57＋1.7 cm before and 0.60＋1.5 cm after）. Flow direction in the LGV was hepatopetal and to-and-fro in 16 patients and hepatofugal in 44 patients before ingestion of glucose. Flow direction changed to hepatofugal in 9 of 16 patients with hepatopetal and to-and-fro blood flow after ingestion of glucose. In 44 patients with hepatofugal blood flow in the LGV, a significant increase in hepatofugal flow velocity was observed in 38 of 44 patients （86%） with esophageal varices. There was a relationship between the percentage changes in flow velocity and the size of varices. Patients who responded excessively to food ingestion might have a high risk for bleeding. The changes of blood flow velocity in the LGV were greater than those in the PV （LGV： 28.3＋26.1%, PV： 7.2＋13.2%, P〈0.01）, whereas no significant changes in the LGV occurred before and after ingestion of glucose in the control subjects. CONCLUSION： Hemodynamics of the PV is unrelated to the degree of endoscopic abnormalities in patients with liver cirrhosis. The most important combinations are endoscopic findings followed by the LGV hemodynamics. Duplex-Doppler ultrasonography has no value in the identification of patients with cirrhosis at risk of variceal bleeding. Hemodynamics of the LGV appears to be superior to those of the PV in predicting bleeding.

Amelioration of hemodynamics and oxygen metabolism by continuous venovenous hemofiltration in experimental porcine pancreatitis

AIM: To investigate the potential role of continuous venovenous hemofiltration (CVVH) in hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis (SAP). METHODS: SAP model was produced by intraductal injection of sodium taurocholate [4%, 1 mL/kg body weight (BW)] and trypsin (2 U/kg BW). Animals were allocated either to untreated controls as group 1 or to one of two treatment groups as group 2 receiving a low-volume CVVH [20 mL/(kg·h)], and group 3 receiving a high-volume CVVH [100 (mL/kg·h)]. Swan-Ganz catheter was inserted during the operation. Heart rate, arterial blood pressure, cardiac output, mean pulmonary arterial pressure, pulmonary arterial wedge pressure, central venous pressure, systemic vascular resistance, oxygen delivery, oxygen consumption, oxygen extraction ratio, as well as survival of pigs were evaluated in the study. RESULTS: Survival time was significantly prolonged by low-volume and high-volume CVVHs, which was more pronounced in the latter. High-volume CVVH was significantly superior compared with less intensive treatment modalities (low-volume CVVH) in systemic inflammatory reaction protection. The major hemodynamic finding was that pancreatitis-induced hypotension was significantly attenuated by intensive CVVH (87.4±12.5 kPa vs116.3±7.8 kPa,P＜0.01). The development of hyperdynamic circulatory failure was simultaneously attenuated, as reflected by a limited increase in cardiac output, an attenuated decrease in systemic vascular resistance and an elevation in oxygen extraction ratio. CONCLUSION: CVVH blunts the pancreatitis-induced cardiovascular response and increases tissue oxygen extraction. The high-volume CVVH is distinctly superior in preventing sepsis-related hemodynamic impairment.

Effect of endotoxin on portal hemodynamic in rats

AIM: To study the effects of endotoxin on portal hemodynamic of normal and noncirrhotic portal hypertensive rats. METHODS: Normal rats were intraperitoneally injected with 0.1, 0.25, 0.5, 1.0, 2.0, 4.0mg.kg(-1) of lipopolysaccharide(LPS) respectively, portal vein ligation(PVL) and intrahepatic portal occlusion (IPO) rats as well as sham-operated rats were treated with an intraperitoneal injection of 1.0mg.kg(-1) of LPS, the portal vein pressure(PVP), portal venous flow(PVF), inferior vena cava pressure(IVCP) and portal vein resistance(PVR) were detected 4 hours after injection. RESULTS: PVF of the 5 groups of rats accepting intraperitoneal injection of LPS were increased from 14.0 to 18.0, 22.2, 26.2, 34.8, 39.6, 38.8 mL.min(-1) 4 hours after injection of LPS(P【0.01). PVP of the 4 groups of rats accepting more than 0.1mg/kg.b.w of LPS was increased from 1.04 to 1.25, 1.50, 1.80, 1.95, 2.05 kPa(P【0.01). The increments of PVF and PVP were in a dose-dependent manner of LPS. PVR of the 5 groups of rats was decreased from 51 to 42,44,48,45,44,47 kPa.min.L(-1) (P【0.05) and no dose-dependent manner was observed. PVF of PVL, IPO and sham-operated rats increased from 22.6 to 32.8, 22.0 to 28.0, 14.0 to 34.8 mL.min(-1) (P【0.01), and PVP increased from 1.86 to 2.24, 1.74 to 1.95, 1.04 to 1.80 kPa(P【0.01), PVR decreased from 71 to 61, 67 to 61, 52 to 44 kPa.min.L(-1) after intraperitoneal injection of 1mg.kg(-1) of LPS. The increments of PVF and PVP of PVL and IPO rats were significantly less than the sham-operated rats(P【0.01), There was no significant difference between the amounts of PVR decreased in the two groups of PHT model rats and sham-operated rats(P】0.05) after intraperitoneal injection 1mg.kg(-1) of LPS. CONCLUSION: Endotoxin could prompt portal hypertension of the normal and noncirrhotic portal hypertensive rats by increasing portal blood flow mainly.

Effects of combined splenorenal shunt devascularization and devascularization only on hemodynamics of the portal venous system in patients with portal hypertension

Shunt and devascularization have totally different effects on hemodynamics of the portal venous system , and the actual results of combined shunt and devascularization should be determined by more clinical observations. This study aimed to evaluate effects on hemodynamics of the portal venous system after conventional spleno-renal shunt combined with pericardial devascularization and pericardial devascularization only. METHODS: In 20 patients who had received conventional splenorenal shunt combined with pericardial devascularization(CP) and 18 who had received pericardial devascularization and splenectomy (PCDV), hemodynamic parameters of the portal venous system were studied by magnetic resonance angiography 1 week before and 2 weeks after operation. Free portal pressure was detected continuously by a transducer during the operation. RESULTS: Compared to the preoperative data, a decreased flow of the portal vein (PVF) (563.12±206.42 ml/min vs 1080.63±352.85 ml/min, P<0.05), a decreased diameter of the portal vein (PVD) (1.20±0.11 cm vs 1.30±0.16 cm, P<0.01 ), a decreased free portal preasure ( FPP ) (21.50±2.67 mmHg vs 29.88±2.30 mmHg, P<0.01) and an increased flow of the superior mesenteric vein (SMVF) (1105.45±309.03 ml/min vs 569.13±178.46 ml/min, P < 0.05) were found in the CP group after operation; a decreased PVD (1.27±0.16 cm vs 1.40±0.23 cm, P<0.05), a decreased PVF (684.60±165.73 ml/min vs 1175.64±415.09 ml/min, P<0.05), a decreased FPP (24.40±3.78 mmHg vs 28.80±3.56 mmHg, P<0.05) and an increased SMVF (697.91+121.83 ml/min vs 521.30±115.82 ml/min, P<0.05) were found in the PCDV group. After operation, the PVF of CP group (563.12±206.42 ml/min vs 684.60±165.73 ml/min, P>0.05) was not decreased significantly while FPP (21.50±2.67 mmHg vs 24.40±3.78 mmHg, P< 0.01) was decreased significantly as compared with that of the PCDV group. PVF and FPP could be decreased by both surgical procedures, but the effect of decreasing FPP is much better in the combined procedures than in PCDV. Since there is no significant difference in PVF between the two groups, the combined procedures could integrate advantages of shunt with those of the devascularization, maintaining the normal anatomy structure of the hepatic portal vein, and should be one of the best choices for patients with PHT when surgical interventions are considered.

Clinical and experimental study of effect of Raondix Salviae Militiorrhiza and other blood activating and stasis eliminating Chinese herbs on hemodynamics of portal hypertension

AIM To study the effects of Radix Salviae Militiorrhiza (RSM), other blood-activating and stasis-eliminating Chinese herbs on hemodynamics of portal hypertension.METHODS Portal pressure of cirrhotic dogs after chronic common bile duct ligation was measured directly; portal blood flow in patients with liver cirrhosis were detected by ultrasound Doppler.RESULTS After administration of RSM and Radix Angelicae Sinensis (RAS) by intravenous infusion in cirrhosis dogs, the portal venous pressure (Ppv), wedge hepatic venous pressure (WHVP), hepatic venous pressure gradient (HVPG), were significantly decreased (P＜0.05-0.01), but the mean arterial pressure (MAP), and the heart rate (HR) remained unchanged. When nifedipine was used, Ppv, WHVP, MAP and HR were significantly decreased (P＜0.05), and the MVPG unchanged (P＞0.05). After administration of RSM, RSM+nifedipine and RSM+Hirudin+Nifedpin for 10-12 weeks, the diameter of portal vein (Dpv), spleen vein (Dsv), the portal venous flow (Qpv) and splenic venous flow (Qsv) in patients with hepatic cirrhosis were significantly lowered (P＜0.05-0.01), and the effect of RAS was weaker.CONCLUSIONS The efficacy of decreasing Ppv by Chinese herbs-RSM, RAS, etc. as compared with nifedipine, demonstrated that the Chinese herbs were slower in action than that of nifedipine, but more long-lasting and without side effects. Hence, long-term administration of Chinese herbs, would be more beneficial.