Hepatic Arterial Blood Flow Research Articles

Portal Hyperperfusion after Extended Hepatectomy Does Not Induce a Hepatic Arterial Buffer Response (HABR) but Impairs Mitochondrial Redox State and Hepatocellular Oxygenation.

Background & AimsPortal hyperperfusion after extended hepatectomy or small-for-size liver transplantation may induce organ dysfunction and failure. The underlying mechanisms, however, are still not completely understood. Herein, we analysed whether hepatectomy-associated portal hyperperfusion induces a hepatic arterial buffer response, i.e., an adaptive hepatic arterial constriction, which may cause hepatocellular hypoxia and organ dysfunction.MethodsSprague-Dawley rats underwent 30%, 70% and 90% hepatectomy. Baseline measurements before hepatectomy served as controls. Hepatic arterial and portal venous flows were analysed by ultrasonic flow measurement. Microvascular blood flow and mitochondrial redox state were determined by intravital fluorescence microscopy. Hepatic tissue pO2 was analysed by polarographic techniques. Hepatic function and integrity were studied by bromosulfophthalein bile excretion and liver histology.ResultsPortal blood flow was 2- to 4-fold increased after 70% and 90% hepatectomy. This, however, did not provoke a hepatic arterial buffer response. Nonetheless, portal hyperperfusion and constant hepatic arterial blood flow were associated with a reduced mitochondrial redox state and a decreased hepatic tissue pO2 after 70% and 90% hepatectomy. Microvascular blood flow increased significantly after hepatectomy and functional sinusoidal density was found only slightly reduced. Major hepatectomy further induced a 2- to 3-fold increase of bile flow. This was associated with a 2-fold increase of bromosulfophthalein excretion.ConclusionsPortal hyperperfusion after extended hepatectomy does not induce a hepatic arterial buffer response but reduces mitochondrial redox state and hepatocellular oxygenation. This is not due to a deterioration of microvascular perfusion, but rather due to a relative hypermetabolism of the remnant liver after major resection.

Assessment of splanchnic hemodynamics in patients with cirrhosis after splenectomy in comparison with non-operated patients at the decompensated stage

Splenectomy in patients with cirrhosis presupposes an increase of blood inflow into portal system to decrease the portal pressure. At the same time there are different opinions about splenectomy. So it is actual to study the character of changes of blood flow in vessels of abdominal cavity in pre- and postsurgical periods and assessment of an influence of these changes on the clinical course of cirrhosis.Aim of research: To assess an influence of splenectomy on the character of changes of splanchnic hemodynamics in patients with cirrhosis comparing to non-operated patients with compensated and decompensated clinical course.Materials and methods: There were examined 190 patients with cirrhosis: gastrointestinal bleeding from oesophagus varicose veins took place in 133 patients, diuretic resistant ascites – in 57 ones. 19 patients underwent splenectomy: 7 – in association with sewing of the left gastric vein and artery, 6 – with “skeletonization” of the lesser curvature of stomach with Nessen’s operation, 2 – with Patsiora’s operation, 2 – with application of selective porto-caval shunt between the low mesenteric vein and the left vein of an ovary. 84 patients died during observation. The duration of observation was from 0.5 to 3.5 years. All patients underwent fibrogastroscopy every 3–4 month. Hemodynamics was assessed on the base of repeated ultrasound of abdominal cavity. There were assessed diameter of hepatic and splenic vessels; qualitative and quantitative characteristics of blood flow in hepatic and splenic arteries, portal and splenic veins.Results of research: Changes of hemodynamics in patients after splenectomy as opposed to non-operative patients are characterized with the decrease of diameter of portal vein at almost stable speed of the linear blood flow in it. The result is some decrease of the volume of portal blood and index of portal blood congestion that indirectly indicates the decrease of portal pressure after splenectomy. At the same time arterial hepatic blood flow stays without essential changes.At fibrogastroscopy there was noticed a decrease of esophageal varicose veins dilatation, its tension, elimination of «red signs” that is a prognostic marker of the menace of bleeding. There were noticed no one relapse of bleeding and the sign of refractory ascites during the period of observation.Conclusio: The changes of splanchnic hemodynamics after splenectomy are characterized with decrease of the volume of splanchnic blood. The result is a decrease of portal pressure that is proved with decrease of congestion index in portal vein, decrease of tension of varicose veins, elimination of “red signs” and consequently elimination of the menace of relapse of bleeding and development of resistant ascites. At the same time splectomy can be done in patients with decompensated clinical course of cirrhosis that is proved with an absence of lethality in postsurgical period

Hepatic Arterial Buffer Response Maintains the Homeostasis of Graft Hemodynamics in Patient Receiving Living Donor Liver Transplantation.

In living donor liver transplantation (LDLT), the hepatic hemodynamics plays important roles in graft regeneration, and the hepatic blood inflows are associated with graft size. However, the data of interplay between the hepatic arterial buffer response (HABR) and graft-to-recipient weight ratio (GRWR) in clinical LDLT are lacking. To identify the effect of the HABR on the hepatic hemodynamics and recovery of graft function and to evaluate the safe lower limit of the GRWR in carefully selected recipients. Portal venous and hepatic arterial blood flow was measured in recipients with ultrasonography, and the graft functional recovery, various complications, and survive states after LDLT were compared. In total, 246 consecutive patients underwent LDLT with right lobe grafts. In total, 26 had a GRWR < 0.7 % (A), 29 had a GRWR between 0.7 and 0.8 % (B), and 181 had a GRWR > 0.8 % (C). For small-for-size syndrome, there was no significant difference (P = 0.176). Graft survival rates at 1, 3, and 5 year were not different (P = 0.710). The portal vein flow and portal vein flow per 100 g graft weight peaks were significantly higher in the A. Hepatic arterial velocity and hepatic arterial flow decreased in all the three groups on postoperative day 1; however, the hepatic arterial flow per 100 g graft weight was close to healthy controls. HABR played important roles not only in the homeostasis of hepatic afferent blood supply but also in maintaining enough hepatic perfusion to the graft.

Assessment of splanchnic hemodynamics in patients with cirrhosis after separating operations in comparison with non-operated patients with compensated and decompensated clinical course

Separating operations are recommended for treatment and prophylaxis of bleeding from varicose veins of gullet as a result of portocaval (azygoportal) shunting at cirrhosis and directed to its elimination using azygoportal separation. At the same time the frequency of relapse of bleeding after operations remains rather high. And the formation of new varicose nodi as a result of disorder of hepatic and splanchnic hemodynamics that inevitably appears at different dates after operation is considered as the main cause of it. At the same time an assessment of hemodynamic changes after azygoportal separation is interpreted in different ways by different authors.Aim of research. To assess an influence of separating surgical interventions on the character of changes of splanchnic hemodynamics in patients with cirrhosis in comparison with non-operated patients with compensated and decompensated clinical course.Material and methods. There were examined 190 patients with cirrhosis: in 133 took place gastrointestinal bleeding from varicose veins of gullet, in 57 – diuretic resistant ascites. 16 patients underwent separating operations. 20 patients underwent endoscopic sclerotherapy of gullet veins. 84 patients died during observation (7 after surgical treatment). Duration of observation was from 2-3 weeks to 2,5-3 years. All patients underwent the repeated ultrasound of abdominal cavity. There were assessed diameter of hepatic and splenic vessels; quantitative and qualitative characteristics of blood flow in hepatic and splenic arteries, portal and splenic veins.Results of research. At assessment of splanchnic hemodynamics the changes of portal blood flow in first months after operation characterized with moderate dilation of portal vein and decrease of linear speed in it. At the same time the volumetric blood flow did not essentially change. It was noticed the decrease of volumetric blood flow in splenic vein at the expense of constriction of its lumen and decrease of linear speed in it. Arterial blood flow characterized with decrease of inflow to liver through hepatic artery and increase of blood flow through splenic artery. At later dates the character of changes of splanchnic hemodynamics after azygoportal separation was analogous on all indicators to non-operated patients at transfer from compensated to decompensated course of cirrhosis – decrease of blood flow through the portal vein and hepatic artery at relative increase of splenic blood flow. An increase of index of stagnation in the portal vein and splenic-hepatic portal index that took place in all operated patients and non-operated ones at the stage of decompensation was an unfavorable prognostic indication.Conclusion. The character of changes of splanchnic hemodynamics after gastroesophageal separation is analogous to non-operated patients at transfer from compensated course of cirrhosis to decompensated one. Decrease of the portal blood inflow through the splenic vein is a compensatory mechanism that must decrease the portal pressure. The quality of life in postsurgical period is determined by duration of compensation of hemodynamic disorders

Assessment of splanchnic hemodynamics in patients with cirrhosis after portocaval shunting in comparison with no-operated patients with the compensated and decompensated course of disease

Portocaval shunting is recommended for decrease of the portal pressure and regression of the varicose veins in patients with cirrhosis. But the shunting surgery at cirrhosis is limited by the high risk of development of hepatic encephalopathy and the hepatocellular insufficiency in post-surgical period. And the disorder of the hepatic and splanchnic hemodynamics that inevitably appears at different dates after surgery is considered as the main cause of these states.Aim of research. To assess an influence of the shunting surgical interventions on the character of changes of splanchnic hemodynamics in patients with cirrhosis in comparison with no-operated patients with compensated and decompensated course of disease.Material and methods. 190 patients with cirrhosis were examined: 133 had gastrointestinal bleeding, 57 – diuretic-resistant ascites. 18 patients underwent surgery – portocaval shunting. 84 patients died during observation (10 after surgery). The duration of observation was from 2-3 weeks to 2,5-3 years.All patients underwent the repeated ultrasound examination of abdominal cavity. There were defined the diameter of hepatic and splenic vessels; quantitative and qualitative characteristics of the blood flow in hepatic and splenic arteries, in portal and splenic veins. Results of research. At assessment of splanchnic hemodynamics we noticed the differences of parameters depending on time that passed after surgery. The changes of portal blood flow in first 3-6 month were characterized by the moderate widening of portal and splenic veins at little decrease of its mean linear and volume speed so an inflow of the portal blood still stable. Arterial blood flow in hepatic artery was forced at the expense of both widening of diameter and increase of the mean speed of blood flow. The splenic arterial blood flow practically was not changed. The reliable decrease of the volume blood flow in portal vein at the expense of decrease of its linear speed was observed in all patients at later dates. An unfavorable sign was an increase of an index of haemostasia in portal vein and of splenic and hepatic portal index in dynamics that took place in all operated patients and in no-operated ones at the stage of decompensation.Conclusions. The character of changes of splanchnic hemodynamics after portocaval shunting is analogous to the one in no-operated patients at transition from the compensated course of cirrhosis to decompensated one. The compensatory mechanism that preserves the volume of the portal inflow to liver is the widening of the portal vein and preservation of the splenic blood flow. The quality of life in post-surgical period is determined by the duration of compensation of hemodynamic disorders

Protective Effect of Nitric Oxide on Liver Circulation from Ischemia Reperfusion Injury

ABSTRACTIntroduction: The reduction of endogenous nitric oxide (NO) production during hepatic ischemia-reperfusion injury, generally via a reduction in endothelial NO synthase activity, leads to liver injury. We hypothesized that administration of an exogenous NO donor into the portal vein may ameliorate hepatic blood flow reduction after a period of ischemia.Material and Methods: A total of 90 min of ischemia (portal vein and hepatic artery) was applied in 15 anesthetized pigs, using the Pringle method under sevoflurane anesthesia. All animals were administered either saline (control group, n = 8) or sodium nitroprusside (SNP, n = 7) as exogenous NO donor drugs into the portal vein, 30 min before and after ischemia. The portal venous blood flow and hepatic artery blood flow were measured continuously using transonic flow probes attached to each vessel. Endogenous NO (NOx = NO2− + NO3−) production was measured every 10 min using a microdialysis probe placed in the left lobe of the liver.Results: In the SNP group, portal venous flow remained unchanged and hepatic artery flow significantly increased compared to baseline. Although the production of liver tissue NOx transiently decreased to 60% after ischemia, its level in the SNP group remained higher than the control saline group.Conclusion: Regional administration of SNP into the portal vein increases hepatic arterial flow during ischemia reperfusion periods without altering mean systemic arterial pressure. We speculate that administration of an exogenous NO donor may be effective in preventing liver injury via preservation of total hepatic blood flow.

Assessment of splenic blood flow in patients with the compensated and decompensated course of cirrhosis

Splenomegaly, increased splenic blood flow are the specific characteristics of the natural course of cirrhosis. But an importance of these alienations is inadequately appreciated when choosing methods of correction the portal hypertensia syndrome.Aim of the study. To assess the splenic blood flow in patients with compensated and decompensated course of cirrhosis.Materials and methods.190 patients with cirrhosis were under surveillance: 123 had the gastrointestinal bleeding, 67 – the refractory ascites. 84 patients died during surveillance. The surveillance lasted from 2-3 weeks to 2,5 -3 years.All patients underwent reiterated ultrasound study of an abdominal cavity. The dimensions of spleen, diameter of hepatic and splenic vessels were assessed; the qualitative and quantitative characteristics of blood flow in hepatic and splenic arteries, portal and splenic veins were defined.Result of the study. All cirrhosis patients have the different degree of splenomegaly with increase of volumetric blood flow in splenic artery and vein in 1,3 and 3,2 times respectively. At the decompensation of disease on the background of decrease of the blood flow in portal vein, hepatic and splenic arteries, the blood flow in splenic vein practically didn’t change. The ratio between the volumetric blood flow in splenic vein and the portal one at decompensation of disease increased from 65,5±18,0 % to 99,1±27,0 %, while the norm is 43,2±15,0 % (р &lt; 0,01), that can be the one of prognostic indications of the complications development.Conclusions. The natural course of cirrhosis characterizes by increase of the splenic blood flow relative to the portal one when transition from the compensated state to the decompensated one, that can be one of the factors of increase of the portal pressure and hemodynamic causes of the complications development that must be taken into account choosing method of correction the syndrome of portal hypertensia

Splenic artery trunk embolization reduces the surgical risk of liver transplantation

Portal hypertension is one of the most important clinical conditions that cause intraoperative intensive hemorrhage in cirrhotic patients undergoing liver transplantation. Pre-transplant portal decompression may reduce the intraoperative bleeding during liver transplantation. Splenic artery trunk embolization (SATE) was performed one month prior to liver transplantation. Platelet count, prealbumin, international normalized ratio, and blood flow in the portal vein and hepatic artery were monitored before and one month after SATE. The measurements above were collected on admission and before surgery in the non-SATE patients, who served as controls. We also recorded the intraoperative blood loss, operating time, required transfusion, post-transplant ascites, and complications within three months after operation in all patients. SATE significantly reduced portal venous blood flow, increased hepatic arterial blood flow, normalized platelet count, and improved prealbumin and international normalized ratio in the patients before liver transplantation. Compared to the non-SATE patients, the pre-transplant SATE significantly decreased the operating time, intraoperative bleeding, post-transplant ascites and severe surgical complications. Pre-transplant SATE decreases portal pressure, improves liver function reserve, and reduces the surgical risk of liver transplantation effectively in patients with severe portal hypertension.

Efficacy of splenic artery trunk embolization with detachable balloon for portal hypertension and hypersplenism

To investigate the efficacy of detachable balloon for splenic artery trunk embolization in patients with cirrhotic portal hypertension and hypersplenism. Eight patients with cirrhotic portal hypertension received splenic artery trunk disconnection using detachable balloons under the guidance of digital subtraction angiography. The diameter and blood flow of the portal vein, the superior mesenteric vein, the splenic vein and the hepatic artery were measured by color Doppler ultrasound. Markers of liver function and blood coagulation, and routine blood parameters were assessed. Gastroscopy was used to evaluate to the degree of gastroesophageal varices. All complications experienced during the perioperative period were recorded. The portal vein diameter decreased from 1.55±0.38 cm to 1.55±0.38 cm, and the splenic artery diameter decreased from 1.45±0.10 cm to 1.41±0.09 cm (P < 0.05). The portal vein blood flow was reduced from 971.52±174.77 ml/min to 785.86±100.17 ml/min, and the splenic vein blood flow decreased from 938.01±208.86 ml/min to 644.02±188.15 ml/min, while the hepatic artery blood flow increased from 261.25±65.47 ml/min to 449.32±84.05 ml/min (P < 0.05). The symptoms of splenism were improved effectively, with platelet counts rising from 37.75±10.61*109/L to 138.63±28.22*109/L after the procedure (P < 0.05). There were no episodes of severe complications or death in the perioperative period, and all patients showed remarkable improvement in markers of liver function and coagulation function, and improvement of esophagogastric varices. The interventional disconnection technique of the splenic artery trunk using detachable balloon for the treatment of portal hypertension and hypersplenism is safe and effective.

Cilostazol improves hepatic blood perfusion, microcirculation, and liver regeneration after major hepatectomy in rats.

Major hepatectomy or small-for-size liver transplantation may result in postoperative liver failure. So far, no treatment is available to improve liver regeneration. Herein, we studied whether cilostazol, a selective phosphodiesterase III inhibitor, is capable of improving liver regeneration after major hepatectomy. Sprague-Dawley rats (n = 74) were treated with cilostazol (5 mg/kg daily) or a glucose solution and underwent either 70% liver resection or a sham operation. Before and after surgery, hepatic arterial and portal venous blood flow and hepatic microvascular perfusion were analyzed. Liver morphology, function, and regeneration were studied with histology, immunohistochemistry, western blotting, and bile excretion analysis. Cilostazol significantly increased hepatic blood flow and microcirculation before and after hepatectomy in comparison with sham-operated controls. This was associated with an elevation of hepatic vascular endothelial growth factor expression, an increase of hepatocellular proliferation, and an acceleration of liver regeneration. Furthermore, cilostazol protected the tissue of the remnant liver as indicated by an attenuation of hepatocellular disintegration. In conclusion, cilostazol increases hepatic blood perfusion, microcirculation, and liver regeneration after a major hepatectomy. Thus, cilostazol may represent a novel strategy to reduce the rate of liver failure after both extended hepatectomy and small-for-size liver transplantation.

Safety and efficacy of splenic artery embolization for portal hyperperfusion in liver transplant recipients: a 5-year experience.

Severe portal hyperperfusion (PHP) after liver transplantation has been shown to cause intrahepatic arterial vasoconstriction secondary to increased adenosine washout (hepatic artery buffer response). Clinically, posttransplant PHP can cause severe cases of refractory ascites and hydrothorax. In the past, we reported our preliminary experience with the use of splenic artery embolization (SAE) as a way to reduce PHP. Here we present our 5-year experience with SAE in orthotopic liver transplantation (OLT). Between January 2007 and December 2011, 681 patients underwent OLT at our institution, and 54 of these patients underwent SAE for increased hepatic arterial resistance and PHP (n=42) or refractory ascites/hepatic hydrothorax (n=12). Patients undergoing SAE were compared to a control group matched by year of embolization, calculated Model for End-Stage Liver Disease score, and liver weight. SAE resulted in improvements in hepatic artery resistive indices (0.92±0.14 and 0.76±0.10 before and after SAE, respectively; P<0.001) and improved hepatic arterial blood flow (HAF; 15.6±9.69 and 28.7±14.83, respectively; P<0.001). Calculated splenic volumes and spleen/liver volume ratios were correlated with patients requiring SAE versus matched controls (P=0.002 and P=0.001, respectively). Among the 54 patients undergoing SAE, there was 1 case of postsplenectomy syndrome. No abscesses, significant infections, or bleeding was noted. We thus conclude that SAE is a safe and effective technique able to improve HAF parameters in patients with elevated portal venous flow and its sequelae.

IMPACT OF THE ANTIVIRAL THERAPY ON CARDIAC HEMODYNAMICS IN PATIENTS WITH CHRONIC VIRAL HEPATITIS

Aim. To study the effect of antiviral therapy (AVT) on some cardiac hemodynamic parameters in patients with chronic viral hepatitis (CVH). Material and methods. Segmental systolic and diastolic functions of the ventricles as well as global diastolic function were evaluated in 25 patients with CVH by pulsed tissue Doppler mapping and by the method of Doppler echocardiography, respectively. The blood flow speed and diameter of blood vessels in liver were determined by ultrasound Doppler. Cardiac hemodynamics was examined in all patients before and after AVT with interferon in combination with ribavirin with formation of persistent virological response. Healthy people (n=19) were included into control group. Results. Reduction in atrial and ventricular sizes, decrease in left ventricular mass, improvement of systolic function of both ventricles, as well as diastolic function of the left ventricle were found in patients with CVH after specific treatment. Reduction in hepatic arterial and portal blood flow speed and a total number of heart rhythm disorders were also observed. Therefore AVT in patients with CVH shows a positive impact on cardiac hemodynamics. Medium-strength correlation (r=0.31; p<0.05) was identified between Еm speed at fibrous ring of mitral valve and high viral load. Strong correlation (r=0.81; p<0.05) was also found between portal vein diameter and Sm speed at fibrous ring of tricuspid valve. Conclusion. Patients with CVH that do not receive AVT have worse prognosis and indicators of cardiac hemodynamics in comparison with patients who receive specific AVT.

RNAi Knockdown of Hypoxia-Inducible Factor-1α Decreased the Proliferation, Migration, and Invasion of Hypoxic Hepatocellular Carcinoma Cells.

The obstruction of hepatic arterial blood flow results in tumor tissue hypoxia and elevated expression of hypoxia-inducible factor-1alpha (HIF-1α). Our study evaluated whether lentivirus-mediated short interference RNA against HIF-1α inhibits proliferation, invasion, and migration of hepatocellular carcinoma (HCC) cells under hypoxia. RNA interference knockdown of HIF-1α was achieved by HIF-1α-directed lentiviral shRNA, in a rat HCC cell line cultured under hypoxia condition for varying length of times. The expression levels of HIF-1α and vascular endothelial growth factor were examined using reverse transcription polymerase chain reaction and western blot analyses. Cell proliferation, migration, and invasion were measured by cell viability, transwell migration, and invasion assays, respectively. Inhibition of HIF-1α expression by shRNA suppressed vascular endothelial growth factor mRNA and protein levels under both normoxia and hypoxia. It also suppressed cell migration and invasion, which were enhanced under hypoxic conditions. RNAi knockdown of HIF-1α further suppressed hypoxia-mediated inhibition of the cell proliferation. These data suggest that shRNA of HIF-1α could antagonize the hypoxia-mediated increase in hepatic cancer cell migration and invasion, and synergize with hypoxia to inhibit the cell proliferation in HCC cells.

Clinical study of color Doppler ultrasound for early diagnosis of acute cholecystitis infection

Objective To investigate the clinical value of color Doppler ultrasound in the early diagnosis of acute cholecystitis infection ,in order to improve the diagnosis of acute cholecystitis infection .Methods 36 cases with acute cholecystitis infection were selected as the observation group , and during the same period the healthy people were randomly selected as the control group .The color Doppler performance of ultrasound was observed .The hepatic artery blood flow velocity and the maximum peak of the cystic artery （Vmax） and resistance index（RI） were meas-ured.ROC curve was observed to evaluate the specificity of color Doppler ultrasound for the disease .Results The incidence rates of weak bile sound transmission ,gallbladder wall thickness ,gallbladder enlargement ,ultrasound Mur-phy positive in the control group were 25.0%,16.7%,22.2%,8.3%,which in the observation group were 72.2%, 47.2%,100.0%,94.4%,the differences were statistically significant （χ2 =4.571,4.571,4.589,5.689,all P 0.05）.Conclusion Color Doppler ultrasound can show the form of acute infectious cholecystitis ,gallbladder wall degree of bile through sound etc .,it can improve the diagnostic value of the disease. Key words: Cholecystitis, acute; Ultrasonography, Doppler, color; Diagnostic imaging

Postoperative morphine concentration in infants with or without biliary atresia and its association with hepatic blood flow.

We measured pre-operative hepatic blood flow and postoperative morphine concentration in infants with or without biliary atresia. Thirty-four infants (0-3 months) with biliary atresia undergoing portoenterostomy (Kasai operation) were included and hepatic blood flow was assessed by magnetic resonance imaging before surgery in 12 of them. Sixteen subjects (0-3 months) without liver disease undergoing abdominal or pelvic surgery acted as controls and six of them had hepatic blood flow assessed. Intravenous morphine (8 μg.kg(-1).h(-1)) was administered to all patients postoperatively. The median (IQR [range]) relative hepatic blood flow was 3.51 (2.72-3.88 [1.68-4.43]) with and 3.15 (2.66-4.42 [2.30-5.01]) without biliary atresia (p = 0.851). The median (IQR [range]) morphine concentration after 24 h infusion was 5.9 (4.5-16.4 [2.9-42.2]) ng.ml(-1) and 6.4 (3.2-12.0 [1.9-48.6]) ng.ml(-1) , respectively (p = 0.460). An inverse regression relation was found between the morphine concentration and the hepatic perfusion index (R(2) = 0.519, p = 0.001). Compensatory increases in hepatic arterial blood flow maintain the total hepatic blood flow in infants with biliary atresia.

Effects of Mn-DPDP and manganese chloride on hemodynamics and glucose tolerance in anesthetized rats

Previous studies have demonstrated that magnetic resonance imaging may be a method of choice to visualize transplanted pancreatic islets. However, contrast agents may interfere with microcirculation and affect graft function. To evaluate the effects manganese-containing contrast media on regional blood flow and glucose tolerance. Anesthetized rats were injected intravenously with MnCl2 (10 µM/kg body weight) or Mn-DPDP (Teslascan™; 5 µM/kg body weight). Blood flow measurements were made with a microsphere technique 10 min later. In separate animals vascular arteriolar reactivity in isolated, perfused islets was examined. Furthermore, an intraperitoneal glucose tolerance test was performed in separate rats. Glucose tolerance was unaffected by both agents. No changes in regional blood flow were seen after administration of Mn-DPDP, except for an increase in arterial liver blood flow. MnCl2 increased all blood flow values except that of the kidney. MnCl2, but not Mn-DPDP, caused a vasoconstriction in isolated rat islet arterioles but only at very high doses. Mn-DPDP administration does not affect glucose tolerance or regional blood flow, besides an increase in arterial hepatic blood flow, and may therefore be suitable for visualization of islets.

Pseudoparallel Channel Sign on Ultrasonography in Alcoholic Hepatitis

Pseudoparallel Channel Sign on Ultrasonography in Alcoholic Hepatitis

Influence of the para-aminohippuric acid analysis method on the net hepatic flux of nutrients in lactating cows1

Para-aminohippuric acid (pAH) is a marker frequently used to measure plasma or blood flow. In sheep studies, it is recognized that its determination must include a deacetylation step to counteract the hepatic acetylation of pAH. Such a procedure is not of common usage in cattle studies although a recent suggestion of hepatic pAH acetylation in dairy cows may have important consequences for hepatic nutrient fluxes. The aims of this study were to evaluate pAH analytical methods according to international procedures of metrology and confirm hepatic acetylation of pAH in dairy cows. The effect of the matrix used to prepare the standard curve was tested, and the influence of the pAH analytical method on blood flows and subsequent net hepatic fluxes of nutrients was determined. For the first objective, accuracy profiles were established and bias, indicators of precision, and limits of quantification were reported for 2 analytical methods (without and with a pAH deacetylation step) using 2 different standard matrices (water and plasma). Second, the net hepatic flux of different nutrients was determined including or not the deacetylation step and preparing the standard curves in plasma using samples collected from 5 multicatheterized lactating Jersey cows. The choice of the matrix had a significant impact on plasma pAH concentrations as illustrated by accuracy profiles. Water matrix decreased (P < 0.01) the slope, y-intercept, and the absorbance at concentration 0 mg pAH/L of the standard curve in both methods (without and with the deacetylation), supporting that standards prepared in water should not be used to analyze plasma samples. Samples collected on cows confirmed hepatic acetylation of pAH across the liver. Deacetylation, performed using plasma as the standard matrix, increased (P < 0.05) plasma pAH concentrations from 18.4, 26, and 23.5 to 21.4, 28.9, and 27.3 mg/L in the artery, portal vein, and hepatic vein, respectively. Deacetylation decreased the hepatic venous and arterial plasma and blood flows (P < 0.05) by 9 and 55%, respectively, modifying the net hepatic flux of acetate, total amino acid, and oxygen by more than 19% (P < 0.05). In conclusion, our results highlight the importance of including a deacetylation step in the pAH analysis method in cattle studies and of using plasma as standard matrix.

Fetal hepatic artery flow assessment in prenatal diagnostics--a review of the literature

Standards of screening tests for the most frequent fetal chromosomal defects in modern non-invasive prenatal diagnostics provide sensitivity of about 93-96%, with the false positive rate of 2.5%. During the first trimester scan, routinely performed between 11 and 13+6 week of pregnancy the calculation of the risk for chromosomal aberrations is based on maternal age (MA), nuchal translucency (NT), levels of free beta human chorionic gonadotropin (free beta-hCG), pregnancy associated plasma protein A (PAPP-A) in maternal blood, as well as the parameters from extended ultrasound examination like evaluation of the nasal bone (NB), blood flow in ductus venosus (DV), visualization of the tricuspid valve with potential regurgitation (TR) or measurement of the frontomaxillary facial angle (FMFA). The 100% detection rate remains unachievable at present, despite constantly improving guidelines for specialists, quality of imaging, and advancement in ultrasound technology Therefore, several studies have been undertaken to establish the group of 'additional markers' of chromosomal defects which, when combined with basic markers of routine screening tests, might increase the detection rate and approach it to 100%. Results of recent studies imply that evaluation of blood flow in fetal hepatic artery performed during the first trimester scan may become a new additional marker for chromosomal defects.

Correlation between hepatic blood flow and liver function in alcoholic liver cirrhosis.

To elucidate the correlation between hepatic blood flow and liver function in alcoholic liver cirrhosis (AL-LC). The subjects included 35 patients with AL-LC (34 men, 1 woman; mean age, 58.9 ± 10.7 years; median age, 61 years; range: 37-76 years). All patients were enrolled in this study after obtaining written informed consent. Liver function was measured with tests measuring albumin (Alb), prothrombin time (PT), brain natriuretic peptide (BNP), branched amino acid and tyrosine ratio (BTR), branched chain amino acid (BCAA), tyrosine, ammonia (NH3), cholinesterase (ChE), immunoreactive insulin (IRI), total bile acid (TBA), and the retention rate of indocyanine green 15 min after administration (ICG R15). Hepatic blood flow, hepatic arterial tissue blood flow (HATBF), portal venous tissue blood flow (PVTBF), and total hepatic tissue blood flow (THTBF) were simultaneously calculated using xenon computed tomography. PVTBF, HATBF and THTBF were 30.2 ± 10.4, 20.0 ± 10.7, and 50.3 ± 14.9 mL/100 mL/min, respectively. Alb, PT, BNP, BTR, BCAA, tyrosine, NH3, ChE, IRI, TBA, and ICG R15 were 3.50 ± 0.50 g/dL, 72.0% ± 11.5%, 63.2 ± 56.7 pg/mL, 4.06 ± 1.24, 437.5 ± 89.4 μmol/L, 117.7 ± 32.8 μmol/L, 59.4 ± 22.7 μg/dL, 161.0 ± 70.8 IU/L, 12.8 ± 5.0 μg/dL, 68.0 ± 51.8 μmol/L, and 28.6% ± 13.5%, respectively. PVTBF showed a significant negative correlation with ICG R15 (r = -0.468, P <0.01). No significant correlation was seen between ICG 15R, HATBF and THTBF. There was a significant correlation between PVTBF and Alb (r = 0.2499, P < 0.05), and NH₃ tended to have an inverse correlation with PVTBF (r = -0.2428, P = 0.0894). There were also many significant correlations between ICG R15 and liver function parameters, including Alb, NH3, PT, BNP, TBA, BCAA, and tyrosine (r = -0.2156, P < 0.05; r = 0.4318, P < 0.01; r = 0.4140, P < 0.01; r = 0.3610, P < 0.05; r = 0.5085, P < 0.001; r = 0.4496, P < 0.01; and r = 0.4740, P < 0.05, respectively). Our investigation showed that there is a close correlation between liver function and hepatic blood flow.