Hepatic blood flow distribution: consideration of gravity, liver surface, and norepinephrine on regional heterogeneity

1993 ◽  
Vol 71 (2) ◽  
pp. 128-135 ◽  
Author(s):  
W. Wayne Lautt ◽  
Joshua Schafer ◽  
Dallas J. Legare
Keyword(s):  
Blood Flow ◽  
Portal Vein ◽  
Hepatic Artery ◽  
Arterial Occlusion ◽  
Flow Distribution ◽  
Arterial Flow ◽  
Blood Flow Distribution ◽  
Hepatic Arterial Flow ◽  
Venous Flow ◽  
Core Samples

Blood flow distribution within the livers of cats and dogs was assessed using 15-μm microspheres injected into the hepatic artery and portal vein. Representative vertical core samples (n = 11–18) were taken from the thickest part of each liver. Heterogeneity was assessed in several ways. The difference in total flow to different lobes was greater in dogs than in cats, and in dogs, those lobes with highest portal venous flow had lowest hepatic arterial flow. Overall flow variance was very high in both species, with adjacent surface samples in a single lobe showing variance of 15–22% for both vessels. The ratio of highest to lowest flow within core samples averaged 2.1–3.4 for both vessels in both species. The hepatic arterial flow was highest to the surface 2 mm of the liver. Portal flow most often (31% of all samples) showed a pattern of highest flow to the top, graduating down to lowest flow to the bottom (dorsal side) of the vertical cores. However, this pattern appeared much more frequently in the most ventral liver lobes and very seldom in the lobes lying beneath the liver mass. Norepinephrine reduced heterogeneity. Hepatic arterial occlusion for 10 min produced minor and inconsistent reduction of heterogeneity. Rotating cats from back to front and again to back disrupted patterns of distribution but not in a way that could be interpreted as due to effects of gravity. Flow patterns changed with time. The heterogeneity of perfusion appears to be under dynamic and multiple interacting forces.Key words: blood flow distribution, blood flow heterogeneity, hepatic artery, portal vein, liver.

Factors influencing control of arterial circulation in the liver of the dog

1963 ◽  
Vol 205 (6) ◽  
pp. 1260-1264 ◽  
Author(s):  
Roy Cohn ◽  
Samuel Kountz
Keyword(s):  
Blood Flow ◽  
Hepatic Artery ◽  
Artery Blood Flow ◽  
Portal Venous Flow ◽  
Hepatic Arterial Flow ◽  
Experimental Conditions ◽  
Venous Flow ◽  
Arterial Circulation ◽  
Factors Influencing ◽  
Intrinsic Regulation

Measurements were made of the hepatic arterial flow in thirty-one mongrel dogs by the use of the electromagnetic square wave flowmeter under the following experimental conditions: hepatic arterial neurectomy, portal venous flow reductions, portal venous flow elimination and diversion, and systemic acidosis and alkalosis. The findings suggest that the periarterial nerves about the hepatic artery influence the intrinsic regulation of hepatic artery blood flow only in the presence of severely reduced portal venous flow.

Intrahepatic blood flow distribution in the perfused rat liver: effect of hepatic artery perfusion

1996 ◽  
Vol 271 (4) ◽  
pp. G561-G567 ◽  
Author(s):  
F. J. Burczynski ◽  
B. A. Luxon ◽  
R. A. Weisiger
Keyword(s):  
Blood Flow ◽  
Portal Vein ◽  
Hepatic Artery ◽  
Rat Liver ◽  
Transit Time ◽  
Flow Distribution ◽  
Low Flow ◽  
Perfused Rat Liver ◽  
Time Dispersion ◽  
Artery Perfusion

Variations in blood flow to different sinusoids within the liver can prevent uniform uptake of solutes from plasma and contribute to cellular ischemia in low-flow states. However, the degree of variability and the role of hepatic artery perfusion in maintaining uniform flow are poorly defined. We used an indicator dilution technique to compare the distribution of sinusoidal transit times in isolated rat livers perfused through the portal vein alone with livers perfused using both portal vein and hepatic artery. Physiological flow rates were used in each case (1.2 +/- 0.3 ml.min-1.g liver-1), but the second group received 32% of flow through the hepatic artery. Intralobular flow heterogeneity was further assessed by gamma counting of small (approximately 100 mg) pieces of the liver after bolus injection of approximately 5 mCi of a highly extracted compound ([125I])triiodothyronine) into the portal vein. Hepatic artery perfusion had no significant effect on mean sinusoidal transit time or intrahepatic distribution volume for 51Cr-labeled red blood cells or 125I-albumin. Analysis of the outflow profiles indicated that hepatic artery perfusion did not affect transit time dispersion. However, heterogeneity of flow to individual portions of the liver, measured as the coefficient of variation, increased from 19 to 30%. These results indicate relatively uniform perfusion of the sinusoids in the portally perfused rat liver and that additional perfusion of the hepatic artery does not further improve hemodynamics. These results have significance for the design and interpretation of transport studies with the use of the perfused rat liver model.

scholarly journals A New Method to Measure Portal Venous and Hepatic Arterial Blood Flow Patients Intraoperatively

HPB Surgery ◽  
1996 ◽  
Vol 9 (4) ◽  
pp. 239-243 ◽  
Author(s):  
F. Jakab ◽  
Z. Ráth ◽  
F. Schmal ◽  
P. Nagy ◽  
J. Faller
Keyword(s):  
Hepatic Artery ◽  
Arterial Flow ◽  
Arterial Blood Flow ◽  
Portal Venous Flow ◽  
Hepatic Arterial Flow ◽  
Venous Flow ◽  
Venous Circulation ◽  
Arterial Blood ◽  
Temporary Occlusion ◽  
Artery Flow

The intraoperative measurement of the afferent circulation of the liver, namely the hepatic artery flow and portal venous flow was carried out upon 14 anesthetized patients having carcinoma in the splanchnic area, mainly in the head of the pancreas by means of transit time ultrasonic volume flowmeter. The hepatic artery flow, portal venous flow and total hepatic flow were 0.377±0.10; 0.614±0.21; 0.992±0.276 l/min respectively.The ratio of hepatic arterical flow to portal venous flow was 0.66±0.259 There was a sharp, significant increase in hepatic arterial flow (29.8±6.1%, p<0,01) after the temporary occlusion of the portal vein, while the temporary occlusion of hepatic artery did not have any significant effect on portal venous circulation. The interaction between hepatic arterial flow and portal venous flow is a much disputed question, but according to the presented data here, it is unquestionable, that the decrease of portal venous flow immediately results a significant increase in hepatic artery circulation.

Numerical Analysis of the VAD Outflow Cannula Positioning on the Blood Flow in the Patient–Specific Brain Supplying Arteries

2020 ◽  
Vol 22 (2) ◽  
pp. 619-636 ◽  
Author(s):  
Zbigniew Tyfa ◽  
Damian Obidowski ◽  
Krzysztof Jóźwik
Keyword(s):  
Blood Flow ◽  
Computer Aided Design ◽  
Volume Flow Rate ◽  
Flow Distribution ◽  
Primary Objective ◽  
Patient Specific ◽  
Blood Flow Distribution ◽  
Reconstruction Process ◽  
Outflow Cannula ◽  
The Brain

AbstractThe primary objective of this research can be divided into two separate aspects. The first one was to verify whether own software can be treated as a viable source of data for the Computer Aided Design (CAD) modelling and Computational Fluid Dynamics CFD analysis. The second aspect was to analyze the influence of the Ventricle Assist Device (VAD) outflow cannula positioning on the blood flow distribution in the brain-supplying arteries. Patient-specific model was reconstructed basing on the DICOM image sets obtained with the angiographic Computed Tomography. The reconstruction process was performed in the custom-created software, whereas the outflow cannulas were added in the SolidWorks software. Volumetric meshes were generated in the Ansys Mesher module. The transient boundary conditions enabled simulating several full cardiac cycles. Performed investigations focused mainly on volume flow rate, shear stress and velocity distribution. It was proven that custom-created software enhances the processes of the anatomical objects reconstruction. Developed geometrical files are compatible with CAD and CFD software – they can be easily manipulated and modified. Concerning the numerical simulations, several cases with varied positioning of the VAD outflow cannula were analyzed. Obtained results revealed that the location of the VAD outflow cannula has a slight impact on the blood flow distribution among the brain supplying arteries.

Mechanisms of improvement in pulmonary gas exchange during isovolemic hemodilution

1999 ◽  
Vol 87 (1) ◽  
pp. 132-141 ◽  
Author(s):  
Steven Deem ◽  
Richard G. Hedges ◽  
Steven McKinney ◽  
Nayak L. Polissar ◽  
Michael K. Alberts ◽  
...  
Keyword(s):  
Blood Flow ◽  
Fractal Dimension ◽  
Gas Exchange ◽  
Spatial Correlation ◽  
Pulmonary Blood Flow ◽  
Minute Ventilation ◽  
Flow Distribution ◽  
Pulmonary Gas Exchange ◽  
Normal Lung ◽  
Blood Flow Distribution

Severe anemia is associated with remarkable stability of pulmonary gas exchange (S. Deem, M. K. Alberts, M. J. Bishop, A. Bidani, and E. R. Swenson. J. Appl. Physiol. 83: 240–246, 1997), although the factors that contribute to this stability have not been studied in detail. In the present study, 10 Flemish Giant rabbits were anesthetized, paralyzed, and mechanically ventilated at a fixed minute ventilation. Serial hemodilution was performed in five rabbits by simultaneous withdrawal of blood and infusion of an equal volume of 6% hetastarch; five rabbits were followed over a comparable time. Ventilation-perfusion (V˙a/Q˙) relationships were studied by using the multiple inert-gas-elimination technique, and pulmonary blood flow distribution was assessed by using fluorescent microspheres. Expired nitric oxide (NO) was measured by chemiluminescence. Hemodilution resulted in a linear fall in hematocrit over time, from 30 ± 1.6 to 11 ± 1%. Anemia was associated with an increase in arterial [Formula: see text] in comparison with controls ( P < 0.01 between groups). The improvement in O2 exchange was associated with reducedV˙a/Q˙heterogeneity, a reduction in the fractal dimension of pulmonary blood flow ( P = 0.04), and a relative increase in the spatial correlation of pulmonary blood flow ( P = 0.04). Expired NO increased with anemia, whereas it remained stable in control animals ( P < 0.0001 between groups). Anemia results in improved gas exchange in the normal lung as a result of an improvement in overallV˙a/Q˙matching. In turn, this may be a result of favorable changes in pulmonary blood flow distribution, as assessed by the fractal dimension and spatial correlation of blood flow and as a result of increased NO availability.

scholarly journals A rare anastomosis between the root of common hepatic artery and proper hepatic artery: implications for pancreaticoduodenectomy

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Takeshi Morinaga ◽  
Katsunori Imai ◽  
Keisuke Morita ◽  
Kenichiro Yamamoto ◽  
Satoshi Ikeshima ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Hepatic Artery ◽  
Pancreatic Head ◽  
Common Hepatic Artery ◽  
Arterial Flow ◽  
Anastomotic Site ◽  
Proper Hepatic Artery ◽  
Arterial Reconstruction ◽  
Hepatic Arterial Flow ◽  
The Common

Abstract Background Hepatic artery anomalies are often observed, and the variations are wide-ranging. We herein report a case of pancreatic cancer involving the common hepatic artery (CHA) that was successfully treated with pancreaticoduodenectomy (PD) without arterial reconstruction, thanks to anastomosis between the root of CHA and proper hepatic artery (PHA), which is a very rare anastomotic site. Case presentation A 78-year-old woman was referred to our department for the examination of a tumor in the pancreatic head. Contrast-enhanced computed tomography (CT) revealed a low-density tumor of 40 mm in diameter located in the pancreatic head. The involvement of the common hepatic artery (CHA), the root of the gastroduodenal artery (GDA), and portal vein was noted. Although such cases would usually require PD with arterial reconstruction of the CHA, it was thought that the hepatic arterial flow would be preserved by the anastomotic site between the root of the CHA and the PHA, even if the CHA was dissected without arterial reconstruction. PD with dissection of the CHA and PHA was safely completed without arterial reconstruction, and sufficient hepatic arterial flow was preserved through the anastomotic site between the CHA and PHA. Conclusion We presented an extremely rare case of an anastomosis between the CHA and PHA in a patient with pancreatic cancer involving the CHA. Thanks to this anastomosis, surgical resection was successfully performed with sufficient hepatic arterial flow without arterial reconstruction.

Pulmonary blood flow distribution after the total cavopulmonary connection for complex cardiac anomalies

1999 ◽  
Vol 14 (3) ◽  
pp. 154-160 ◽  
Author(s):  
Masao Tayama ◽  
Nobuaki Hirata ◽  
Tohru Matsushita ◽  
Tetsuya Sano ◽  
Norihide Fukushima ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Flow Distribution ◽  
Total Cavopulmonary Connection ◽  
Blood Flow Distribution ◽  
Cardiac Anomalies ◽  
Cavopulmonary Connection
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