A computational model-based study on the exchangeability of hepatic venous pressure gradients measured in multiple hepatic veins

2020 ◽  
Vol 84 ◽  
pp. 28-35
Author(s):  
Tianqi Wang ◽  
Fuyou Liang ◽  
Lei Li ◽  
Wen Zhang ◽  
Guangchuan Wang ◽  
...  
1992 ◽  
Vol 262 (1) ◽  
pp. G14-G22 ◽  
Author(s):  
R. Maass-Moreno ◽  
C. F. Rothe

We tested the hypothesis that the larger (greater than 2 mm ID) hepatic veins are the primary site of the portal-to-caval venous pressure gradient in the dog. Double-lumen catheters were inserted through the caval wall into hepatic veins of pentobarbital sodium-anesthetized dogs. One lumen opened at the end, and the other to the side. Each catheter was advanced until stopped and then it was withdrawn. The pressure at either port dropped from 87 +/- 31 to 13 +/- 11% of the portal-to-caval pressure difference as each moved past a transition point (TP). The location of the TP depended on the catheter diameter. Intraportal histamine or norepinephrine, 4 and 2.6 micrograms.min-1.kg body wt-1 respectively, augmented only the pressure measured upstream to the TP. A mathematical model of flow through a vessel with a catheter inside predicted a marked increase in resistance when the ratio of catheter OD to vessel ID exceeded approximately 0.6. Autopsy revealed ratios greater than 0.6 upstream to the TP. A hydraulic model confirmed that this effect caused the appearance of the TP. Given the depth (11.7 cm) at which near caval pressures could be found, even during histamine administration, we conclude that the major pressure gradients in the canine liver must lie upstream to the large hepatic veins.


2018 ◽  
Vol 40 ◽  
pp. 23-32 ◽  
Author(s):  
Vedrana Baličević ◽  
Hrvoje Kalinić ◽  
Sven Lončarić ◽  
Maja Čikeš ◽  
Bart Bijnens

2021 ◽  
Vol 75 (2) ◽  
pp. 125-133
Author(s):  
Soňa Franková ◽  
Jan Šperl

Portal hypertension represents a wide spectrum of complications of chronic liver diseases and may present by ascites, oesophageal varices, splenomegaly, hypersplenism, hepatorenal and hepatopulmonary syndrome or portopulmonary hypertension. Portal hypertension and its severity predicts the patient‘s prognosis: as an invasive technique, the portosystemic gradient (HPVG – hepatic venous pressure gradient) measurement by hepatic veins catheterisation has remained the gold standard of its assessment. A reliable, non-invasive method to assess the severity of portal hypertension is of paramount importance; the patients with clinically significant portal hypertension have a high risk of variceal bleeding and higher mortality. Recently, non-invasive methods enabling the assessment of liver stiffness have been introduced into clinical practice in hepatology. Not only may these methods substitute for liver biopsy, but they may also be used to assess the degree of liver fibrosis and predict the severity of portal hypertension. Nowadays, we can use the quantitative elastography (transient elastography, point shear-wave elastrography, 2D-shear-wave elastography) or magnetic resonance imaging. We may also assess the severity of portal hypertension based on the non-invasive markers of liver fibrosis (i.e. ELF test) or estimate clinically signifi cant portal hypertension using composite scores (LSPS – liver spleen stiff ness score), based on liver stiffness value, spleen diameter and platelet count. Spleen stiffness measurement is a new method that needs further prospective studies. The review describes current possibilities of the non-invasive assessment of portal hypertension and its severity.


1986 ◽  
Vol 251 (3) ◽  
pp. G375-G381 ◽  
Author(s):  
W. W. Lautt ◽  
C. V. Greenway ◽  
D. J. Legare ◽  
H. Weisman

The pressure drop from the portal vein to the vena cava occurs primarily across a postsinusoidal site localized to a narrow segment (less than 0.5 cm) of hepatic veins (roughly 1.5 mm diam) in the anesthetized cat. Portal venous pressure (PVP = 8.9 +/- 0.3 mmHg) and lobar hepatic venous pressure (LVP = 8.7 +/- 0.4 mmHg) are insignificantly different, and pressure changes imposed from the presinusoidal or postsinusoidal side are equally transmitted to both pressure sites. Several types of experiments were done to validate the LVP measurement. The portal vein, hepatic sinusoids, and hepatic veins proximal to the resistance site are all under a similar pressure. Previously reported calculations of hepatic vascular resistance are in error because of incorrect assumptions of sinusoidal pressure and localization of the portal resistance site as presinusoidal. Stimulation of hepatic sympathetic nerves for 3 min caused LVP and PVP to increase equally, showing that the increased "portal" resistance is postsinusoidal across the same region of the hepatic veins that was previously localized as the site of resistance in the basal state.


1996 ◽  
Vol 1 (3-4) ◽  
pp. 391-396
Author(s):  
Mingyuan Jin ◽  
Lishan Kang ◽  
Dechun Peng

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