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.

FloTrac/Vigileo监测活体肝移植患者血流动力学变化及临床分析更多〉〉相关学者黄志强严律南郑树森周宁新董家鸿吴孟超席淑华朱康顺张青萍单鸿相关检索词血流动力学 liver transplantation变异 记录心率 脑缺血监测系统 反应性输液 机体全麻 手术后并发症再灌注 移植术容量 hemodynamics变化规律 平均动脉压脉压 活体肝移植 FloTrac/Vigileo监测活体肝移植患者血流动力学变化及临床分析

目的 应用FloTrac/Vigileo监测系统探讨活体肝移植患者术中血流动力学变化规律,为临床麻醉管理提供参考.方法 肝移植患者28例,静吸复合全麻下行活体部分肝移植术.分别于切皮前即刻（T0）、无肝期5 min（T1）、无肝期30 min （T2）、新肝期5min（T3）、新肝期30min（T4）和术毕（T5）记录心率（HR）、平均动脉压（MAP）、心排量（C0）、心脏指数（CI）、每搏量（SV）、每搏变异度（SVV）等指标.结果 与To比较,患者HR在T1～5升高（P＜0.01）；MAP、CO、CI和SV于T1～4降低（P均＜0.01）,T5时恢复至切皮前水平（P ＞0.05）；SVV于T1～2升高（P＜0.01）,T3～4降低（P＜0.05）,T5恢复至切皮前水平（P＞0.05）.结论 活体肝移植患者无肝期和新肝再灌注早期循环抑制明显,应根据不同时期机体对容量负荷的反应性合理输液,并进行有效的循环支持.

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.

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.

Effects of somatostatin on splanchnic hemodynamics in cirrhotic patients with portal hypertension

INTRODUCTIONEsophageal variceal bleeding (EVB) is one of themost common complications of cirrhosis with portalhypertension.In recent years,great progress hasbeen made in medicinal treatment.Somatostatin hasbeen widely used in clinics,for it can effectivelylower the portal venous pressure (PVP) with

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.

Hepatic hemodynamic changes during liver transplantation: A review

Liver transplantation is performed in the recent decades with great improvements not only technically but also conceptually. However, there is still lack of consensus about the optimal hemodynamic characteristics during liver transplantation. The representative hemodynamic parameters include portal vein pressure, portal vein flow, and hepatic venous pressure gradient; however, there are still others potential valuable parameters, such as total liver inflow and hepatic artery flow. All the parameters are correlated closely and some internal modulating mechanisms, like hepatic arterial buffer response, occur to maintain stable hepatic inflow. To distinguish the unique importance of each hepatic and systemic parameter in different states during liver transplantation, we reviewed the published data and also conducted two transplant cases with different surgical strategies applied to achieve ideal portal inflow and pressure.

Hemodynamics and oxygen transport dynamics during hepatic resection at different central venous pressures in a pig model

BACKGROUND: Although low central venous pressure (CVP) has been used to minimize blood loss during hepatectomy the impact of variations of CVP on the rate of blood loss and on the perfusion of end-organs has not been evaluated This animal study aimed to evaluate the hemodynamics and oxygen transport changes during hepatic resection at different CVP levels. METHODS: Forty-eight anesthetized Bama miniature pigs were divided into 8 groups with CVP during hepatic resection controlled at 0 to <1, 1 to <2, 2 to <3, 3 to <4, 4 to <5, 5 to <6, 6 to <7, and 7 to <8 cmH 2 O. Intergroup comparisons were made for hemodynamic parameters, oxygen transport dynamics, and the rate of blood loss. RESULTS: The rate of blood loss and the hepatic venous pressure during hepatic resection were almost linearly related to the CVP. A significant drop in the mean arterial pressure cardiac output, and cardiac index occurred between CVP ≥2 and <2 cmH 2 O. Oxygen delivery (DO 2 ), oxygen consumption (VO 2 ) and oxygen extraction ratio (ERO 2 ) remained relatively constant between CVPs of 2 to <8 cmH 2 O. There was a significant drop in DO 2 when the CVP was <2 cmH 2 O. There was also a significant drop in VO 2 and ExO 2 when the CVP was <1 cmH 2 O.CONCLUSION: The optimal CVP for hepatic resection is 2to 3 cmH2O.

Effects of propofol versus urapidil on perioperative hemodynamics and intraocular pressure during anesthesia and extubation in ophthalmic patients

AIM: To compare the effect of propofol versus urapidil on hemodynamics and intraocular pressure during anesthesia and extubation for ophthalmic patients. METHODS: Eighty-two surgical patients (Class: ASA I-II) were randomly assigned to propofol (n = 41) and urapidil groups (n = 41). Their gender, age, body mass, operation time and dosage of anesthetics had no significant difference between the two groups (P > 0.05). The patients of propofol and urapidil groups were given propofol (1.5mg/kg) and urapidil (2.5mg/kg) respectively; and two drugs were all diluted with normal saline to 8mL. Then the drugs were given to patients by slow intravenous injection. After treatment, the patients were conducted immediate suction, tracheal extubation, and then patients wore oxygen masks for 10 minutes. By double-blind methods, before the induction medication, at the suction, and 5, 10 minutes after the extubation, we recorded the systolic and diastolic blood pressure (BP), heart rate (HR), pH, PaO2, PaCO2, SaO(2) and intraocular pressure (TOP) respectively. The complete recovery time of the patients with restlessness (on the command they could open eyes and shaking hands) was also recorded during the extubation. The data were analyzed by using a professional SPSS 15.0 statistical software. RESULTS: The incidence of cough, restlessness and glossocoma was significantly lower in the propofol group than that in the urapidil group after extubation (P < 0.05). There were no episodes of hypotension, laryngospasm, or severe respiratory depression. There was no statistical difference in recovery time between two groups (P > 0.05). In propofol group, the BP and HR during extubation and thereafter had no significant difference compared with those before induction, while they were significantly lower than those before giving propofol (P < 0.05), and had significant difference compared with those in urapidil group (P < 0.05). Compared to preinduction, the BP of urapidil group showed no obvious increase during aspiration and extubation. The HR of urapidil group had little changes after being given urapidil, and it was obviously increased compared with that before induction. The stimulation of aspiration and extubation caused less cough and agitation in propofol group than that in urapidil group (P < 0.05). The IOP of propofol group showed no obvious increase during extubation compared with that in preinduction, while in the urpidil group, extubation caused IOP significantly increased (P < 0.05). The changes in these indicators between the two groups had no significant difference (P > 0.05). CONCLUSION: Compared to urapidil, propofol is superior for preventing the cardiovascular and stress responses and IOP increases during emergence and extubation for the ophthalmic patients. Moreover, it has no effects on patient's recovery.

Early changes of hepatic hemodynamics measured by functional CT perfusion in a rabbit model of liver tumor

BACKGROUND:Early detection and treatment of hepatocellular carcinoma is crucial to improving the patients’ survival.The hemodynamic changes caused by tumors can be serially measured using CT perfusion.In this study,we used a CT perfusion technique to demonstrate the changes of hepatic hemodynamics in early tumor growth,as a proof-of-concept study for human early hepatocellular carcinoma.METHODS:VX2 tumors were implanted in the liver of ten New Zealand rabbits.CT perfusion scans were made 1 week(early) and 2 weeks(late) after tumor implantation.Ten normal rabbits served as controls.CT perfusion parameters were obtained at the tumor rim,normal tissue surrounding the tumor,and control liver;the parameters were hepatic blood flow,hepatic blood volume,mean transit time,permeability of capillary vessel surface,hepatic arterial index,hepatic arterial perfusion and hepatic portal perfusion.Microvessel density and vascular endothelial growth factor were correlated.RESULTS:At the tumor rim,compared to the controls,hepatic blood flow,hepatic blood volume,permeability of capillary vessel surface,hepatic arterial index,and hepatic arterial perfusion increased,while mean transit time and hepatic portal perfusion decreased on both early and late scans(P<0.05).Hepatic arterial index increased(135%,P<0.05),combined with a sharp increase in hepatic arterial perfusion(182%,P<0.05) and a marked decrease in hepatic portal perfusion(-76%,P<0.05) at 2 weeks rather than at 1 week(P<0.05).Microvessel density and vascular endothelial growth factor showed significant linear correlations with hepatic blood flow,permeability of capillary vessel surface and hepatic arterial index,but not with hepatic blood volume or mean transit time.CONCLUSION:The CT perfusion technique demonstrated early changes of hepatic hemodynamics in this tumor model as proof-of-concept for early hepatocellular carcinoma detection in humans.

Goal-directed therapy in intraoperative fluid and hemodynamic management

Intraoperative fluid management is pivotal to the outcome and success of surgery, especially in high-risk proce- dures. Empirical formula and invasive static monitoring have been traditionally used to guide intraoperative fluid management and assess volume status. With the awareness of the potential complications of invasive procedures and the poor reliability of these methods as indicators of volume status, we present a case scenario of a patient who underwent major abdominal surgery as an example to discuss how the use of minimally invasive dynamic monitoring may guide intraoperative fluid therapy.

The effect of aneurismal-wall mechanical properties on patient-specific hemodynamic simulations:two clinical case reports

Hemodynamic factors such as the wall shear stress play an important role in the pathogenesis and treatment of cerebral aneurysms. In present study, we apply computational fluid-structure interaction analyses on cerebral aneurysms with two different constitutive relations for aneurismal wall in order to investigate the effect of the aneurismal wall mechanical properties on the simulation results. We carry out these analyses by using two patient-specific models of cerebral aneurysms of different sizes located in different branches of the circle of Willis. The models are constructed from 3D rotational angiography image data and blood flow dynamics is studied under physiologically representative waveform of inflow. From the patient models analyzed in this investigation, we find that the deformations of cerebral aneurysms are very small. But due to the nonlinear character of the Navier-Stokes equations, these small deformations could have significant influences on the flow characteristics. In addition, we find that the aneurismal-wall mechanical properties have great effects on the deformation distribution of the aneurysm, which also affects the wall shear stress distribution and flow patterns. Therefore, how to define a proper constitutive relation for aneurismal wall should be considered carefully in the hemodynamic simulation.

Effect of obstructive jaundice on hemodynamics in the liver and its clinical significance

BACKGROUND: Many diseases can cause obstructive jaundice and then lead to a series of pathologic disorders. Thus preoperative assessment of liver function is of utmost importance. Traditional assessment is to monitor related indicators of liver function, but it is invasive and needs to be performed repeatedly. Color Doppler flow imaging (CDFI) was used to monitor blood flow of the hepatic artery and portal vein, a non-invasive method which can be used repeatedly. METHODS: Twenty cases of obstructive jaundice were detected by CDFI and changes of liver function were measured after operation. The variables of hemodynamic monitoring included peak flow rate and mean blood flow in the hepatic artery proper at the peak of the contraction period; the inner diameter of blood vessels, the peak flow rate, and the congestion index, the blood flow in the main portal vein. RESULTS: The average peak flow rate in the hepatic artery of patients with obstructive jaundice was significantly higher than that of normal people; both the inner diameter and congestive index of the portal vein were significantly larger than those of normal people. But the mean blood flow and peak flow rate in the portal vein were lower than those of normal people. CONCLUSIONS: CDFI is an ideal and non-invasive method for evaluating liver hemodynamics in obstructive jaundice. If the increase of hepatic arterial flow is more significant than the decrease of the blood flow in the portal vein, hepatic functional recovery after operation is smoother, suggesting a better prognosis. If the increase of the hepatic arterial flow is less significant than the decrease of the blood flow in the portal vein, hepatic functional recovery after operation may not be smooth, suggesting a worse prognosis.

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.

Asymmetrical traumatic bilateral hip dislocations with hemodynamic instability and an unstable pelvic ring: Case report and review of literature

Simultaneous anterior and posterior traumatic dislocations of both hips are very rare. Only 33 cases have been previously reported in the English language literature. Although they were all due to high-energy injuries, they were hemodynamically stable and had a stable pelvic ring. We report a unique case of asymmetrical hip dislocations with an unstable pelvic ring and hemodynamic instability. A 40-year-old man was injured in a high-energy motor vehicle accident. He was hemodynamically unstable when he presented in the emergency department. Radiolographs showed asymmetrical dislocations of both hips with an unstable pelvic ring. Under general anesthesia, he had closed reduction of the dislocations of both hips, followed by temporary stabilization with an external fixator. Transcatheter arterial embolization was performed to stop active pelvic bleeding. Delayed open reduction and internal fixation was performed 12 d later with anterior and posterior plates. The patient recovered well with an uneventful post-operative course. Asymmetrical bilateral hip dislocations with pelvic ring instability caused by trauma, as presented in this case, is very rare and potentially life threatening. Prompt treatment can give a good outcome.

Hemodynamic changes in hepatic sinusoids of hepatic steatosis mice

BACKGROUND Fatty liver(FL) is now a worldwide disease. For decades, researchers have been kept trying to elucidate the mechanism of FL at the molecular level, but rarely involve the study of morphology and medical physics. Traditionally, it was believed that hemodynamic changes occur only when fibrosis occurs, but it has been proved that these changes already show in steatosis stage, which may help to reveal the pathogenesis and its progress. Because the pseudolobules are not formed during the steatosis stage, this phenomenon may be caused by the compression of the liver microcirculation and changes in the hemodynamics.AIM To understand the pathogenesis of hepatic steatosis and to study the hemodynamic changes associated with hepatic steatosis.METHODS Eight-week-old male C57 BL/6 mice were divided into three groups randomly(control group, 2-wk group, and 4-wk group), with 16 mice per group. A hepatic steatosis model was established by subcutaneous injection of carbon tetrachloride in mice. After establishing the model, liver tissue from mice was stained with hematoxylin and eosin(HE), and oil red O stains. Blood was collected from the angular vein, and hemorheological parameters were estimated. A two-photon fluorescence microscope was used to examine the flow properties of red blood cells in the hepatic sinusoids.RESULTS Oil red O staining indicated lipid accumulation in the liver after CCl_4 treatment.HE staining indicated narrowing of the hepatic sinusoidal vessels. No significant difference was observed between the 2-wk and 4-wk groups of mice onmorphological examination. Hemorheological tests included whole blood viscosity(mPas, γ = 10 s-1/γ = 100 s-1)(8.83 ± 2.22/4.69 ± 1.16, 7.73 ± 2.46/4.22 ±1.32, and 8.06 ± 2.88/4.22 ± 1.50), red blood cell volume(%)(51.00 ± 4.00, 42.00 ±5.00, and 40.00 ± 3.00), the content of plasma fibrinase(g/L)(3.80 ± 0.50, 2.90 ±0.80, and 2.30 ± 0.70), erythrocyte deformation index(%)(44.49 ± 5.81, 48.00 ±15.29, and 44.36 ± 15.01), erythrocyte electrophoresis rate(mm/s per V/m)(0.55 ±0.11, 0.50 ± 0.11, and 0.60 ± 0.20), revealing pathological changes in plasma components and red blood cells of hepatic steatosis. Assessment of blood flow velocity in the hepatic sinusoids with a laser Doppler flowmeter(mL/min per100 g)(94.43 ± 14.64, 80.00 ± 12.12, and 67.26 ± 5.92) and two-photon laser scanning microscope(μm/s)(325.68 ± 112.66, 213.53 ± 65.33, and 173.26 ± 44.02)revealed that as the modeling time increased, the blood flow velocity in the hepatic sinusoids decreased gradually, and the diameter of the hepatic sinusoids became smaller(μm)(10.28 ± 1.40, 6.84 ± 0.93, and 5.82 ± 0.79).CONCLUSION The inner diameter of the hepatic sinusoids decreases along with the decrease in the blood flow velocity within the sinusoids and the changes in the systemic hemorheology.

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.

Hemodynamic and morphologic changes of peripheral hepatic vasculature in cirrhotic liver disease: A preliminary study using contrast-enhanced coded phase inversion harmonic ultrasonography

AIM: To provide the useful information for the diagnosis of liver cirrhosis by observing the morphology of peripheral hepatic vessels and the hemodynamics of microbubble arrival time in these vessels.METHODS: Twenty-one subjects including 5 normal volunteers and 16 patients (liver cirrhosis, n=10;chronic hepatitis, n=6) were studied by contrast-enhanced coded phase inversion harmonic sonography (GE LOGIQ9 series) using a 6-8 MHz convex-arrayed wide-band transducer. The images of peripheral hepatic artery,portal and hepatic vein were observed in real-time for about 2 min after intravenous injection of Levovist. The time when microbubbles appeared in the peripheral vessels (microbubble arrival time) was also recorded. The morphologic changes of peripheral hepatic vasculature were classified as marked, slight, and no changes based on the regularity in caliber, course, ramification, and the delineation of vessels compared to normal subjects.RESULTS: The microbubble arrival time at peripheral artery, portal, and hepatic vein was shorter in cirrhotic patients than in chronic hepatitis patients and normal subjects. The marked, slight and no morphologic changes of peripheral hepatic vasculature found in 5 (5/6,83.3%), 1 (1/6, 16.7% ), and 0 (0/6, 0%) liver cirrhosis patients, respectively, and in 1 (1/10, 10%), 6 (6/10,60%), and 3 (3/10, 30%) chronic hepatitis patients,respectively. There was a significant difference between the two groups (P＜0.001).CONCLUSION: Evaluation of the hemodynamics and morphology of peripheral hepatic vasculature by contrast-enhanced coded pulse inversion harmonic sonography can provide useful information for the diagnosis of liver cirrhosis.

Effects of environmental hypothermia on hemodynamics and oxygen dynamics in a conscious swine model of hemorrhagic shock

BACKGROUND:Hypothermia is associated with poor outcome in trauma patients;however,hemorrhagic shock(HS)model with anesthetized swine was different from that of clinical reality.To identify the effects of environmental hypothermia on HS,we investigated hemodynamics and oxygen dynamics in an unanesthetized swine model of HS under simulating hypothermia environment.METHODS:Totally 16 Bama pigs were randomly divided into ambient temperature group(group A)and low temperature group(group B),8 pigs in each group.Venous blood(30 mL/kg)was continuously withdrawn for more than 15 minutes in conscious swine to establish a hemorrhagic shock model.Pulmonary arterial temperature(Tp),heart rate(HR),mean arterial pressure(MAP),pulmonary arterial pressure(PAP),pulmonary arterial wedge pressure(PAWP),central venous pressure(CVP),cardiac output(CO),hemoglobin(Hb),saturation of mixed venous blood(SvO_2)and blood gas analysis were recorded at the baseline and different hemorrhagic shock time(HST).The whole body oxygen delivery indices,DO_2l and VO_2l,and the O_2 extraction ratio(O_2ER)were calculated.RESULTS:Core body temperature in group A decreased slightly after the hemorrhagic shock model was established,and environmental hypothermia decreased in core body temperature.The mortality rate was significantly higher in group B(50%)than in group A(0%).DO_2l and VO_2l decreased significantly after hemorrhage.No difference was found in hemodynamics,DO_2l and VO_2l between group A and group B,but the difference in pH,lactic acid and O_2ER was significant between the two groups.CONCLUSION:Environmental hypothermia aggravated the disorder of oxygen metabolism after hemorrhagic shock,which was associated with poor prognosis.

Effects of somatostatin analog on splanchnic hemodynamics and plasma glucagon level in portal hypertensive rats

IM To investigate the effects of somatostatin analog on splanchnic hemodynamics and plasma glucagon level in portal hypertensive rats.METHODS Twentyeight male SpragueDawley rats were divided into two groups: intrahepatic portal hypertension (IHPH, n=14) by injection of CCl4 and prehepatic portal hypertension (PHPH, n=14) by stenosis of the portal vein. Animals of each group were divided into two subgroups: injection of octreotide and injection of normal saline. Seven agematched normal rats served as controls. The mean systemic arterial pressure (MSAP) and free portal venous pressure (FPP) were measured. The splanchnic blood flow was detected by injection of toad blood red cell labelled with 51Cr and 125I·T3. The concentration of plasma glucagon was determined by radioimmunoassay.RESULTS Octreotide significantly decreased both the splanchnic blood flow and FPP in portal hypertensive rats, and markedly increased splanchnic vascular and portal venous resistance. Octreotide did not significantly lower the plasma glucagon levels in both the peripheral and the portal veins.CONCLUSION The decreased splanchnic blood flow induced by octreotide in portal hypertensive rats results mainly from direct vasoconstriction but less from decreased plasma glucagon level.