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PubMed1973

Liver structure and function following small bowel resection.

The observation that patients with extensive small bowel resection have impaired hepatocellular function with reduced BSP clearance and fatty change in biopsies from the liver led to a systematic study of liver structure and function following proximal and distal small bowel resection in the rat. While anaesthesia and surgery impaired BSP clearance per se, small bowel resection further reduced BSP clearance with impairment of both uptake and excretion phases of BSP excretion. The increased BSP retention was more marked after distal than after proximal small bowel resection, but in both experimental groups the abnormalities of BSP excretion spontaneously returned to normal three to four weeks after surgery. Circulating liver enzymes were normal but serum alkaline phosphatase was significantly depressed, particularly after distal resection. Isoenzyme studies showed that the depression of serum AP was due to a reduced intestinal isoenzyme. While serum levels remained consistently depressed up to eight weeks after proximal resection, in parallel with mucosal regeneration, serum AP returned to normal two to four weeks after ileectomy. While these minor changes in hepatic structure and function would normally be of little clinical importance, the additional insult of hepatic dysfunction may well be important in malnourished patients after extensive small bowel resection.

Adult↗
PubMed2003

Portomesenteric disconnection for small-for-size grafts in liver transplantation: Preclinical studies in pigs.

This study reviews the evaluation and results of a new liver transplantation technique for small-for-size grafts with portomesenteric disconnection. Twenty Large-White pigs underwent heterotopic liver transplantation after a mesocaval shunt, ligation of the superior mesenteric vein downstream from the shunt, and ligation of the recipient portal vein near the native liver. The donor-to-recipient weight ratio was 24%, and the graft-to-recipient weight ratio was 0.6%. In five control pigs, no mesocaval shunt was performed. The mesocaval shunt provided diversion of 60% of the splanchnic blood flow. The median survival of study pigs was 39 days (range, 8 to 98). Median serum bilirubin levels at 1 week were 12 micromol/L (range, 4 to 59). At autopsy, graft weight was increased to 2.7 times the initial weight and histologic findings were normal. In the control group, all pigs died quickly of acute splanchnic congestion. Portomesenteric disconnection was effective to achieve survival of small-for-size grafts in pig liver transplantation.

Animals↗
PubMed2002

Impairment of hepatosplanchnic oxygenation and increase of serum hyaluronate during normothermic and mild hypothermic cardiopulmonary bypass.

UNLABELLED: Hepatic sinusoidal endothelial cells (SECs) are more vulnerable to hypoxia or hypothermia than hepatocytes. To test the hypothesis that hepatic venous desaturation during cardiopulmonary bypass (CPB) leads to impairment of SEC function, we studied the plasma kinetics of endogenous hyaluronate (HA), a sensitive indicator of SEC function, and hepatosplanchnic oxygenation during and after CPB. Twenty-five consecutive patients scheduled for elective coronary artery bypass graft surgery, who underwent normothermic (>35 degrees C; n = 15) or mild hypothermic (32 degrees C; n = 10) CPB participated in this study. A hepatic venous catheter was inserted into each patient to monitor hepatosplanchnic oxygenation and serum levels of HA concentration. Hepatic venous oxygen saturation decreased essentially to a similar degree during normothermic and mild hypothermic CPB. Hepatosplanchnic oxygen consumption and extraction increased during normothermic (P < 0.05), but not mild hypothermic, CPB. Both arterial and hepatic venous HA concentrations showed threefold increases during and after CPB in both groups. A positive correlation was found between hepatosplanchnic oxygen consumption and arterial HA concentrations during CPB, suggesting a role of changes in hepatosplanchnic oxygen metabolism in the mechanisms of increases in serum HA concentrations. The failure of the liver to increase HA extraction to a great degree suggests that a functional impairment of the SEC may contribute to the observed increase of serum HA. IMPLICATIONS: Hepatic sinusoidal endothelial cells (SECs) are pivotal in the regulation of sinusoidal blood flow. This study showed that SEC function might be impaired during and after cardiopulmonary bypass, irrespective of the temperature management.

Aged↗
PubMed1992

Measurement of visceral blood flow with magnetic resonance imaging.

With the increasing application of magnetic resonance imaging (MRI) and MR angiography in parenchymal liver disease, methods are becoming more widely available for noninvasive measurement of visceral blood flow. Amplitude-based (time-of-flight) and phase-based techniques have proved effective for measurement of portal blood flow, and phase-sensitive methods are applicable to arterial flow measurements. Because respiratory motion degrades the quality of examinations in the abdomen, it is desirable to use methods that can generate flow information in a breath-hold period. Although substantial technical difficulties persist for quantitative arterial flow measurements in the abdomen, the technical requirements for venous flow are less stringent, and important clinical information can be derived using straightforward techniques. The authors describe the principles of flow measurement using time-of-flight and phase methods in visceral arteries and veins, and discuss their practical implementation. Clinical applications are discussed, based on the experience of the authors and others working in the field.

Blood Flow Velocity↗
PubMed2002

Increased hepatosplanchnic inflammation precedes the development of organ dysfunction after elective high-risk surgery.

This study investigated the relationship of the hepatosplanchnic production and uptake of inflammatory mediators, hepatosplanchnic perfusion, and outcome during major abdominal surgery to evaluate the hypothesis that regional production of inflammatory mediators precedes the development of hepatic dysfunction. This retrospective analysis of data and blood samples collected during a randomized controlled clinical trial included high-risk surgical patients undergoing major abdominal surgery in a 24-bed university-afilliated intensive care unit. Patients were divided into a subgroup that developed hepatic dysfunction (HD+) postoperatively and a subgroup without hepatic dysfunction (HD-). Hepatic vein and arterial plasma levels of IL-6, IL-8, s-E-selectin, s-ICAM-1, and the TNF-receptors 55 and 75 were measured, and the flux was calculated by multiplying the difference in hepatic vein minus arterial levels of the mediators by the hepatosplanchnic flow. Systemic (thermodilution) and total hepatosplanchnic blood flow (using indocyanine green [ICG]-dilution method) and gastric intramucosal pH (pHi) were assessed preoperatively, 4, 24, and 36 h postoperatively. Of a total of 26 patients, 6 patients developed hepatic dysfunction after their abdominal surgery (mean 6 days postoperatively). The number of sepsis-related deaths and postoperative days on the ventilator were significantly higher in this group. A higher production of IL-8, TNF-receptor-75 and 55 in the hepatosplanchnic area in the HD+ subgroups was found, which preceded the development of organ dysfunction (P = 0.04, P = 0.02, and P = 0.02, respectively). Moreover, the uptake of s-ICAM-1 was significantly increased in this subgroup. Furthermore, total hepatosplanchnic blood flow was significantly higher and pHi was significantly lower in the HD+ group, whereas global hemodynamic data were similar in the two subgroups. In conclusion, the development of postoperative organ dysfunction is preceded by an increased regional inflammatory response, indicated by an increased soluble TNF-receptor shedding and IL-8 production from the hepatosplanchnic area together with an increased uptake of s-ICAM-1. Moreover, an increased total hepatosplanchnic blood flow with intramucosal acidosis was associated with this regional inflammatory response.

Aged↗
PubMed1984

Influence of somatostatin on splanchnic haemodynamics in patients with liver cirrhosis.

The influence of intravenous somatostatin infusion (7.6 micrograms/min) on systemic and splanchnic haemodynamics was examined in 10 patients with liver cirrhosis and portal hypertension. The hepatic vein catheter technique was employed and indocyanine green dye was injected to evaluate hepatic blood flow. Mean wedged hepatic venous pressure fell from 24.9 +/- 2.8 in the basal state to 21.4 +/- 3.2 mmHg (P less than 0.2) at 60 min of infusion and the mean arterial pressure decreased from 87 +/- 5 to 80 +/- 6 mmHg (P less than 0.05). The rate of indocyanine green dye disappearance decreased from 8.7 +/- 1.9 to 6.6 +/- 1.7%/min (P less than 0.001) during the infusion, indicating decreased hepatic blood flow. Arterial-hepatic venous oxygen differences rose from 69 +/- 11 to 78 +/- 11 ml/l. Blood glucose levels fell from 4.84 +/- 0.31 to 3.79 +/- 0.33 mmol/l at 60 min of infusion (P less than 0.005). It is concluded that a continuous infusion of somatostatin in patients with liver cirrhosis and portal hypertension causes a decreased hepatic blood flow with augmented hepatic oxygen extraction and a modest reduction in mean wedged hepatic venous pressure. In view of the magnitude of the observed haemodynamic changes the findings do not suggest an important role for somatostatin in the treatment of patients with bleeding oesophageal varices.

Adult↗
PubMed2006

Endothelin-1 contributes to maintenance of systemic but not portal haemodynamics in patients with early cirrhosis: a randomised controlled trial.

BACKGROUND AND AIMS: Increased endothelin (ET)-1 activity may contribute to the complications of cirrhosis and portal hypertension. The aim of this study was to assess the systemic and portal haemodynamic effects of selective ET-A and ET-B receptor antagonism in patients with cirrhosis. METHODS: Sixteen patients with cirrhosis and portal hypertension (aged 52 (1) years, Pugh score 6.2 (0.3)) underwent 24 studies with infusions of: (A) selective ET-A antagonist, BQ-123 (n = 8), at 1000 and 3000 nmol/min; (B) selective ET-B antagonist, BQ-788 (n = 8), at 100 and 300 nmol/min; or (C) matched saline placebo (n = 8) in a double blind randomised manner. Haemodynamic measurements were performed through pulmonary artery, hepatic venous, and femoral artery catheters. RESULTS: Baseline patient characteristics were well matched. Compared with placebo, BQ-123 decreased mean arterial pressure (MAP -15 (11) mm Hg (-18%); p<0.02) and pulmonary vascular resistance index (PVRI -81 (54) dyn x s x m2/cm5 (-64%); p<0.05), with no effect on hepatic venous pressure gradient (HVPG), cardiac index (CI), or systemic vascular resistance index (SVRI). Compared with placebo, BQ-788 increased MAP (+11 (3) mm Hg (+12%); p<0.03) and SVRI (+1101 (709) dyn x s x m2/cm5 (+50%); p<0.05), reduced CI (-1.0 (0.4) l/min/m2 (-29%); p = 0.05) with no effect on HVPG or PVRI. CONCLUSIONS: ET-1 contributes to maintenance of systemic and pulmonary haemodynamics without acutely affecting HVPG in patients with early cirrhosis. In this group of patients, the use of selective ET-A and ET-B antagonists for the management of variceal haemorrhage is likely to be limited.

Adult↗
PubMed1989

Hemodynamic effects of a combination of clonidine and propranolol in conscious cirrhotic rats.

The hemodynamic effects of the combination of clonidine and propranolol were studied in conscious rats with portal hypertension owing to secondary biliary cirrhosis. Pressure and blood flow measurements (radioactive microsphere method) were performed in three groups of eight rats before and after drug administration. The combined effects of clonidine (2 micrograms/100 g body wt., i.v.) and propranolol (0.2 mg/min for 10 min) were compared with those observed after administration of either clonidine alone or propranolol alone. The association of clonidine and propranolol induced significant decreases in portal pressure (30%) and portal tributary blood flow (43%), the magnitude of these changes being significantly more marked than that after administration of either clonidine alone (12 and 20%, respectively) or propranolol alone (16 and 17%, respectively). After the combination, no significant change in arterial pressure was observed, but cardiac output significantly decreased and systemic vascular resistance significantly increased. Renal blood flow decreased to a similar extent (40%) in the three groups. These findings indicate that the combination of clonidine and propranolol is more effective for reversing splanchnic hemodynamic changes than clonidine alone or propranolol alone. The additive effects of this association are in agreement with the action of clonidine and propranolol at different levels (central and peripheral) and on different receptors (alpha and beta). It suggests that an increase in sympathetic activity may play a major role in hemodynamic changes observed in experimental cirrhosis.

Animals↗
PubMed2003

[The effect of dopexamine and iloprost on plasma disappearance rate of indocyanine green in patients in septic shock].

OBJECTIVES: To evaluate the effect of dopexamine and iloprost on the plasma disappearance rate (PDR) of indocyanine green (ICG) in patients in septic shock in a prospective clinical trial. METHODS: In 40 consecutive patients in septic shock, a femoral arterial fiberoptic catheter (COLD system) and a gastrotonometric probe were placed. Patients received either dopexamine infusion (0.5 microgram/kg body weight/min) or iloprost (1 ng/kg body weight/min) for 24 h i.v. PDR, intramucosal pH of stomach wall (pHi), cardiac index (HI) and intrathoracic blood volume (ITBV) were determined before, 1, 6, and 24 h after dopexamine or iloprost infusion and 1 h after end of infusion. RESULTS: PDR was significantly increased 24 h after starting dopexamine infusion from 12.2 +/- 1.8%/min to 17.8 +/- 2.2%/min (+45.9%) and 1 h after the end of infusion PDR decreased to baseline values. PDR increased to 16.4 +/- 2.1%/min, 1 h after starting iloprost infusion and increased to a maximum value of 18.6 +/- 2.2%/min (+33.8%, p < 0.05) 24 h after start of infusion compared to the baseline (13.9 +/- 1.7%/min). After the end of infusion PDR decreased to baseline values. Baseline values of pHi were in normal ranges in all groups and there was no change during the observation period. Cardiac index and ITBV were stable during the study. Dosage of norepinephrine could be reduced by dopexamine infusion. CONCLUSIONS: Dopexamine and iloprost have a positive effect on the plasma disappearance rate of ICG and therefore have a protective effect on splanchnic perfusion and liver function, respectively.

Adult↗
PubMed1987

Reduction of intrahepatic vascular space in the pathogenesis of portal hypertension. In vitro and in vivo studies in the rat.

To elucidate a possible role for reduction of intrahepatic vascular space in the pathogenesis of portal hypertension, we studied a partially hepatectomized rat model in vitro and in vivo. The in vitro study used livers from normal, 1/3-hepatectomized, and 2/3-hepatectomized rats, and rats with cirrhosis caused by chronic bile duct ligation, for isolated, perfused flow-pressure plotting. Resistance to perfusion increased such that significant differences were found between all groups except the last two, which showed similar resistances. The in vivo study measured splanchnic blood flow by radioactive microspheres and portal pressure in anesthetized sham-operated and 1/3- and 2/3-hepatectomized rats. Although absolute portal tributary blood flows did not change, portal flow per gram of remnant liver showed significant increases: 1.57 +/- 0.32 ml/min X g liver, 2.52 +/- 0.60 ml/min X g liver, p less than 0.01; 3.48 +/- 1.04 ml/min X g liver, p less than 0.01, respectively. Although intrahepatic resistance increased significantly only in the 2/3-hepatectomized group, portal pressures increased significantly in both groups of hepatectomized rats: normal, 7.5 +/- 1.1 mmHg; 1/3-hepatectomized, 9.4 +/- 1.1 mmHg; and 2/3-hepatectomized, 11.1 +/- 1.2 mmHg. Thus, decreased intrahepatic vascular space caused by resection and hepatocellular hypertrophy leads to portal hypertension, thereby suggesting that this reduction in space may be the pathogenic factor common to a number of different theories of portal hypertension.

Animals↗
PubMed2006

[Low-MI-sonography with the contrast-agent SonoVue in the diagnosis of infarction of the spleen, kidney, liver and pancreas].

PURPOSE: The diagnosis of ischemic injury by B-mode-sonography is difficult in many cases. Aim of the pilot-study was to evaluate whether additional examination with the ultrasound contrast agent SonoVue could improve the sonographic diagnosis of ischemic injury. MATERIALS AND METHODS: In a prospective study, intra-abdominal organs (n = 12) with ischemic lesions found by CT-scan were examined. All ischemic organs were examined by native B-mode-sonography and after injection of 1.2 ml SonoVue i. v. The SonoVue-examinations were performed using the CPS-software (Siemens, Erlangen). RESULTS: Native B-mode-sonography detected demarcation of ischemic lesions in only 7 of the 12 organs. In contrast, SonoVue-enhanced sonography diagnosed ischemic lesions in all organs. In one patient with renal infarction, however, the ischemic lesion found by SonoVue-enhanced sonography was smaller compared with the CT-scan. The diagnosis "compatible with ischemia" as cause for the abnormalities in B-mode sonography was described in only 3 out of 12 organs, and none of the organs were classified as "definite diagnosis of ischemia". In contrast, the diagnosis "definite diagnosis of ischemia" was made in 10 of the 12 organs when examined with SonoVue-enhanced sonography. In two further patients, the lesion was classified as "compatible with ischemia". In these patients, the diagnosis of ischemia was verified by CT-scan, due to the accompanying subtotal splenic infarction and a partial thrombosis of the coeliac trunc. CONCLUSION: It became evident that SonoVue-enhanced sonography was more sensitive in the diagnosis of ischemic injury than native B-mode sonography.

Abdomen, Acute↗
PubMed1990

Effects of ketamine, halothane, enflurane, and isoflurane on systemic and splanchnic hemodynamics in normovolemic and hypovolemic cirrhotic rats.

The effects of ketamine, halothane, enflurane, and isoflurane on systemic and splanchnic hemodynamics in cirrhotic rats that were either normovolemic or hypovolemic following hemorrhage were characterized. Rats received at random either ketamine (30 mg/kg iv, 1.5 mg.kg-1.min-1 iv), halothane, enflurane, or isoflurane (1 MAC). Conscious rats were considered the control group. Four weeks before hemodynamic studies bile duct ligation was performed in all rats to induce cirrhosis. Hemodynamic measurements were performed using the radioactive microsphere method 1 h after the onset of anesthesia and 30 min after hemorrhage. Anesthetized rat lungs were mechanically ventilated with room air. Before hemorrhage cardiac index was higher in conscious rats and in rats receiving isoflurane than in the other groups (P less than 0.001). Hepatic arterial blood flow was similar in conscious rats and in those receiving isoflurane or halothane and was higher than in those receiving ketamine or enflurane. The lowest splanchnic and portal venous tributary blood flows were observed in rats receiving enflurane. After hemorrhage cardiac index was significantly less than before hemorrhage in all groups, except in rats receiving enflurane. After hemorrhage portal venous tributary blood flow decreased significantly in all groups except in enflurane group. During halothane and enflurane anesthesia hepatic arterial blood flow and hepatic arterial fraction of cardiac output decreased (P less than 0.01) and they were maintained in the other groups. After hemorrhage hepatic arterial fraction of cardiac output in conscious rats was higher than in those receiving ketamine, halothane, or enflurane (P less than 0.05) and was similar to those receiving isoflurane.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Disturbance of hepatic and intestinal microcirculation in experimental liver cirrhosis.

AIM: To analyze hepatic, mesenteric and mucosal microcirculation and leukocyte-endothelium interaction (LEI) in a rat model with liver cirrhosis. METHODS: Hepatic cirrhosis was induced in Wistar rats by gavage with carbon tetrachloride, and intravital videomicroscopy was performed in liver, mesentery and small intestine mucosa. Special emphasis is given on microcirculatory and morphometric changes during cirrhotic portal hypertension. RESULTS: LEI was influenced significantly in the cirrhotic liver but not in the gut. Blood flow measurement showed significant differences among liver, main mesenteric vessels and the mucosa. The results of our study indicate that liver cirrhosis leads to alterations in hepatic and mesenteric blood flow but not in mucosal blood flow. CONCLUSION: The enhanced inflammatory response in hepatic microvessels may be caused by a decrease of antithrombin III levels and could be responsible for disturbances of organ pathology.

Animals↗
PubMed1991

Selective dopamine DA1 stimulation with fenoldopam in cirrhotic patients with ascites: a systemic, splanchnic and renal hemodynamic study.

We studied the effects of fenoldopam, a selective dopamine DA1 agonist on systemic and splanchnic hemodynamics, renal blood flow and sodium excretion in 12 patients with alcoholic cirrhosis and ascites. Hepatic, azygos and renal veins were catheterized before and after intravenous administration of fenoldopam, 0.05 micrograms/kg/min for 1 hr and increased to 0.1 micrograms/kg/min for another hour. Mean arterial pressure progressively decreased (from 83 +/- 7 to a minimum of 77 +/- 8 mm Hg 100 min after starting the infusion) but returned to baseline level at 120 min. Plasma norepinephrine and renin activity increased (respectively from 567 +/- 297 to 919 +/- 375 pg/ml, p less than 0.05, and from 17 +/- 14 to 23 +/- 15 ng/ml/hr, p less than 0.05). Renal blood flow, urine output or sodium excretion did not change. Sodium output decreased at 1 hr from 6.9 mumol/min to 4.0 mumol/min, p less than 0.05. Both hepatic venous pressure gradient and azygos blood flow significantly increased by 21%. We conclude that the acute administration of fenoldopam did not improve renal hemodynamics or function in patients with cirrhosis and ascites. In addition, dopamine DA1 agonism caused further increases in norepinephrine concentration and plasma renin activity. Portal pressure also increased, probably because of an increase in mesenteric blood flow. These results question the renal benefit and raise concern about the use of dopamine agonists in patients with cirrhosis and ascites.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMedDate not supplied

[Changes in the enzyme activity of the hydroxylating system of the rat liver endoplasmic reticulum in ischemia].

Local disturbance of liver circulation for 40 minutes did not lead to any substantial changes in the hydroxylation system of microsomes of the ischemized area. 60-, 120- and 180-minute circulation distress causes a progressing decrease in amidopyrine and aniline metabolism, diminution of the content of cytochrome P-450 in the microsomes, and of the activity of NADP.H-ferricytochrome-c-reductase, NADP.H-neotetrazolium-reductase and NADP.H-oxidase. After 120-minute ischemia hydrophobic properties of the microsomal membranes were found to be decreased.

Animals↗
PubMed1996

Long-term hemodynamic effects of portocaval shunt and Sugiura procedure in patients with cirrhosis.

Systemic and splanchnic hemodynamics were studied before and six months after a portal systemic shunt (n = 6) or a Sugiura procedure (n = 9) in 15 patients with cirrhosis and a past history of variceal bleeding. Hepatic blood flow was estimated by hepatic extraction and clearance of continuous indocyanine green infusion. Azygos blood flow was measured with a continuous thermodilution catheter. After portocaval shunt, the cardiac index increased significantly from 4.0 +/- .4 to 5.4 +/- 0.8 l/min m2 (p < 0.05), the hepatic venous pressure gradient and hepatic blood flow were significantly decreased from 21 +/- 3 to 13 +/- 5 mm Hg (p < 0.05) and from 1.20 +/- 0.35 to 0.37 +/- 0.16 l/min (p < 0.05) respectively. The decrease in azygos blood flow was not significant (0.51 +/- 0.31 vs 0.25 +/- 0.33 l/min; p = 0.1). After Sugiura procedure, there was no significant change in cardiac index, hepatic venous pressure gradient, hepatic blood flow or azygos blood flow. This is the first study to show the long-term maintenance of splanchnic and systemic hemodynamics in patients with cirrhosis after Sugiura procedure. The absence of long-term hemodynamic alterations could explain the absence of encephalopathy after this procedure.

Azygos Vein↗
PubMed1985

Effect of somatostatin on splanchnic hemodynamics in patients with liver cirrhosis and portal hypertension.

The effect of somatostatin on splanchnic hemodynamics in patients with liver cirrhosis is not clearly defined, as some authors report a decrease in portal pressure and in liver blood flow during intravenous administration of this hormone, while others do not. In 19 subjects with liver cirrhosis and portal hypertension the following parameters were measured before and during intravenous administration of somatostatin (7.5 micrograms/min): porto-hepatic gradient, estimated hepatic blood flow, specific splenic blood flow, cardiac index. Estimated hepatic blood flow decreased significantly during somatostatin infusion (p less than 0.05), averaging a 13% decrease; porto-hepatic gradient, splenic specific blood flow and cardiac index did not vary significantly. These data indicate that somatostatin infused at a dose of 7.5 micrograms/min induces a slight decrease in liver blood flow without affecting portal hypertension.

Adult↗