Portal Flow Mean Velocity Research Articles

Hepatic microcirculatory thrombosis in acute-on-chronic hepatic failure

BackgroundAcute-on-chronic hepatic failure is an increasing number of identified distinct disorders encompassing an acute deterioration of hepatic functions in patients with chronic liver diseaseAimThe aim was to evaluate the possibility of hepatic microcirculatory thrombosis in acute-on-chronic hepatic failure and the value of plasma fibrin monomer (FM) and D-dimer in the diagnosis.Patients and methodsA total of 50 patients with chronic hepatitis C infection developing new-onset ascites, encephalopathy, and/or jaundice with raised international normalisation ratio (INR) (group 1); group 2 included 30 patients with compensated chronic hepatitis C virus infection who served as the control group. Ascetic fluid examination and culture were done for group 1, in addition to complete blood count, liver enzymes, INR, serum bilirubin and albumin, blood culture, α-fetoprotein, D-dimer, plasma FM, abdominal ultrasound, and Doppler for portal vein were done for all patients groups.ResultsGroup 1was subdivided according to the level of FM into subgroups A and B. FM showed a significant difference between group 1A and other groups; group IB showed nonsignificant elevation of the level of FM and a significant increase in D-dimer compared with the control group. A marked reduction in portal flow mean velocity in group 1A was recorded with further deterioration of portal flow direction after 2 weeks from the admission time. Three months follow-up showed significant reduction of FM, improvement of portal flow mean velocity and direction in group 1A; FM was significantly positively correlated with portal flow mean velocity.ConclusionHepatic microcirculatory thrombosis may occur in acute-on-chronic hepatic disease; determination of the FM and D-dimer level may be useful biomarkers predicting hepatic microcirculatory thrombosis.

Value of soluble fibrin as a biomarker for intrahepatic microthrombosis and its sequel acute-on-chronic liver failure in chronic hepatitis C patients

Background: There is a lack in finding the precipitating factor in acute –on chronic liver failure (ACLF)insult in large number of patients and either this factor is hepatic or extra hepatic origin. Aim of the work : Our study aiming to evaluate the potential usefulness of a new plasma soluble fibirin polymer (SF) assay for diagnosing the possibility of occurrence of intrahepatic microthrombosis as a cause of ACLF in patients with chronic hepatitis C virus. Patients & Methods: The study was carried out in Zagazig University Hospital, internal medicine department in collaboration with microbiology department from February 2015 tell November 2015. 50 patients having chronic hepatitis c virus was enrolled in this study with ACLF developing new onset ascitis in 15 patient encephalopathy in 12 patients, jaundice in12 and elevated INR in 11 patients all having regular follow-up in hepatology clinic in Zagazig university Hospital with stable clinical course in the previous three months. Control subject was classified as normal subject 20 and 30 patients with compensated chronic hepatitis C virus infection. All patients and control groups were subjected to full history, complete clinical examination and laboratory tests including CBC, INR, serum albumin, serum bilirubin, liver enzymes, ascitic fluid examination and culture, blood culture, alpha-fetoprotein, d D-dimer, thrombin generation and soluble fibrin polymer., abdominal ultrasound, Doppler ultrasound for portal vein. Results: Our results showed significant difference between patients group and both control groups regarding SF and D-dimer, also there were significant differences in patients group and other groups regarding ALT, total bilirubin especially direct bilirubin. There were marked reduction in portal flow mean velocity in patients group and other groups and we recorded further reduction in the portal flow mean velocity in patients group after 2 weeks from the starting time. There is significant positive correlation between SF and D-dimer with ALT, bilirubin, INR, portal flow mean velocity and increasing amount of ascitis and degree of encephalopathy. Conclusion: Evaluation the level of soluble fibrin polymer is a useful biomarker to predict ACLF development. Further studies are needed to insure its value and the best modality of treatment in this condition.Research Highlight 1- Soluble fibrin as a biomarker for intrahepatic microthrombosis 2- The possibility of intrahepatic microthrombosis in developing acute-on-chronic liver failure in chronic hepatitis C patients

Effect of Levovist® on splanchnic hemodynamics in cirrhotic patients

This study was aimed to assess the effect of Levovist® on Doppler parameters of splanchnic hemodynamics. A total of 12 patients with cirrhosis and 12 healthy subjects underwent Doppler ultrasound (US) examination of the portal vein and of the hepatic, splenic and superior mesenteric arteries before, 5 to 8 and 12 to 15 min after the start of an 8-min long IV infusion of 2.5 g of Levovist®. Mean velocity and mean diameter were calculated for the portal vein. Resistance index was determined for the arteries. A significant increase of resistance index was observed in the hepatic (0.80 ± 0.07 vs. 0.71 ± 0.06; p < 0.01) and splenic arteries (0.72 ± 0.06 vs. 0.64 ± 0.06; p < 0.01) 5 to 8 min after contrast agent injection in patients with cirrhosis, but not in controls. Neither portal vein diameter nor portal flow mean velocity changed during the test in both controls and cirrhotic patients. This effect might be related to a selective trapping of microbubbles in the altered hepatic and splenic microvasculature in patients with cirrhosis rather than being artefactual. It might have implications on harmonic imaging US protocols designed to image the cirrhotic liver in the early arterial phase. (E-mail: sgaiani@med.unibo.it)

Beneficial Hemodynamic Effects of Dipyridamole on Portal Circulation in Cirrhosis

Dipyridamole is a vasodilator that inhibits the cellular uptake of adenosine, which physiologically reduces the resistance to hepatic arterial flow inside the liver. This study aims at assessing the acute effect of dipyridamole on functional liver plasma flow (measured as the extrarenal sorbitol clearance) and on the Doppler US Congestion Index of the portal vein (the ratio between the cross-sectional area of this vein and the mean velocity of portal flow), which correlates with the severity of portal hypertension. We have determined the extrarenal sorbitol clearance (14 cases) and the Congestion Index (seven cases) before and at 30, 60, and 90 min after the oral administration of 25 mg dipyridamole in patients with liver cirrhosis. We also measured the effect of dipyridamole on functional liver plasma flow in six healthy subjects. Dipyridamole increased the extrarenal sorbitol clearance in controls (+17%, p < 0.01) and in cirrhotic patients (+15%, p < 0.01). The drug decreased the portal Congestion Index in all patients, averaging 24% ( p < 0.05) 90 min after its oral administration. This result was due both to a mean decrease of the portal sectional area and to a mean increase in portal flow velocity. In conclusion, these data suggest that dipyridamole should decrease the vascular resistance to portal flow in cirrhosis; this effect may be mediated by an adenosine-dependent vasodilation in the intrahepatic site or along the portosystemic collaterals.

The relationship of endoscopy, portal doppler ultrasound flowmetry, and clinical and biochemical tests in cirrhosis

The relationship of the endoscopic aspect of esophageal varices, portal quantitative Doppler ultrasound parameters and clinical and biochemical findings was assessed in 149 patients with cirrhosis stratified according to the presence of esophageal varices (n = 115) and the absence of previous bleeding (n = 96). In this series of patients the presence of esophageal varices and red signs proved to be significantly correlated with the severity of cirrhosis. However, in the group of patients with varices, no correlation was found between variceal size and the degree of liver failure. Portal blood flow velocity was significantly different in the endoscopic subgroups, but not in the clinical and biochemical subgroups. Furthermore, portal blood flow velocity was found to correlate only with the presence and size of esophageal varices. The Congestion Index of the portal vein (derived from the ratio between the cross-sectional area of the portal vein and the mean velocity of portal flow) was significantly different in most clinical, biochemical and endoscopic subgroups and was correlated with liver function, presence and size of varices, and presence and degree of red signs. We conclude that the Congestion Index of the portal vein, the clinical status and the endoscopic aspect of varices are not independent features in patients with cirrhosis. As for liver function and endoscopic findings, portal Doppler ultrasound parameters, in particular the Congestion Index, may contribute to a better clinical assessment in patients with cirrhosis.

Changes in splanchnic hemodynamics in inflammatory bowel disease. Non-invasive assessment by Doppler ultrasound flowmetry.

An increase in splanchnic blood flow in both arterial and venous beds has been demonstrated in inflammatory bowel disease (IBD) by means of angiographic and scintigraphic studies. Doppler ultrasound (US) enables a non-invasive evaluation of splanchnic arterial inflow in the superior mesenteric artery (SMA) and of venous outflow in the portal vein. The aim of this study was to assess the role of Doppler US in detecting changes in the hemodynamic variables measured in patients with IBD. Forty-five patients with IBD were studied, including 22 with Crohn's disease (CD) and 23 with ulcerative colitis (UC), and compared with 45 matched normal subjects. The mean velocity of portal flow (Vmean) and the resistance index (RI) of the SMA were evaluated by Doppler US. In CD the Vmean of portal flow was significantly higher in patients with active disease than in controls (p less than 0.001) and patients with inactive disease (p less than 0.001). The RI of the SMA was significantly lower in active disease than in controls (p less than 0.005), but no significant difference was noted between active and inactive CD. Also in UC, the Vmean of portal flow was significantly higher in patients with active disease than in controls (p less than 0.01) and patients with inactive disease (p less than 0.05). The RI of the SMA was significantly lower in active disease than in controls (p less than 0.005) and in patients with inactive disease (p less than 0.005). Doppler follow-up studies were carried out in 10 patients after initiation of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Metoclopramide on Transmural Oesophageal Variceal Pressure and Portal Blood Flow in Cirrhotic Patients

This study was undertaken to evaluate the effect of metoclopramide on transmural oesophageal variceal pressure and portal blood flow in cirrhotic patients. Sixteen cirrhotics were randomly assigned to metoclopramide (10 mg i.v.) or saline. Metoclopramide significantly decreased transmural variceal pressure (15.7% decrease, p less than 0.05 vs. basal value). In order to evaluate if the metoclopramide-induced drop in transmural variceal pressure was due to an effect on portal haemodynamics, we also measured, by means of real time and pulsed Doppler ultrasonography, portal vein diameter, mean velocity of portal flow, and portal venous flow. No significant change was observed before and after metoclopramide. In conclusion, metoclopramide, which increases lower oesophageal sphincter pressure, significantly decreases transmural variceal pressure in cirrhotic patients. However, it does not have any effect on portal haemodynamics.

Method for Measurement of Gastrointestinal Absorption in Normal Animals, Combining Portal-Carotid Differences and Telemetered Portal Flow by Doppler Shift1,2

The Doppler Ultrasonic Blood Flow System was used to measure the portal blood flow rate (mean 40.9 ml/min/kg) in seven calves ranging from 3 to 22 weeks of age, fed milk at 5% of body weight twice daily. Absorption estimates of total sugars and glucose were made by combining portal flow and portal-carotid blood concentration differences. Telemetry of blood flow information permitted measurements on unattended animals in a normal environment. Mean velocity of portal flow one hour postprandial was increased 9.7% by feeding. Net absorption of total sugars and glucose determined from plots of portal-carotid concentration differences over the 12-hour feeding interval, combined with the portal flow rate, accounted for 60% (calculated as glucose and galactose) of the lactose intake. Glucose alone accounted for 41% of the lactose intake. Difference between the total sugars and glucose absorbed indicates that some galactose or lactose per se is absorbed. Data also indicate that 20 to 40% of the fed lactose is not accounted for as absorbed sugar, suggesting utilization in the gut wall. The method developed, using Doppler shift principle to measure blood flow and portal-carotid concentration differences, is suitable for obtaining quantitative determinations of net absorption of nutrients from the gastrointestinal tract of ruminants in a normal environment.