Effect on hemodynamics of a liquid meal alone and in combination with propranolol in cirrhosis

Heterogeneity of treatment response to beta-blockers in the treatment of portal hypertension: A systematic review

BACKGROUND

It has been suggested that a relevant proportion of patients do not respond to nonselective beta-blockers (NSBB)s, which raises questions regarding the need for individualized therapy. The existence of potential heterogeneity in the treatment response can be assessed using the variability ratio (VR) of the outcome measurement (in this case, HVPG) between the treated and placebo groups. We conducted a systematic review and meta-analysis of randomized controlled trials to assess the potential heterogeneity in the portal pressure response to NSBBs.

METHODS

After a systematic search, we quantified the heterogeneity of treatment response with the VR between the treatment and control groups, with VR > 1 indicating potential heterogeneity. We used a similar approach to compare carvedilol with propranolol and statins with placebo.

RESULTS

We identified 18 studies that included 965 patients. A comparison between beta-blockers and placebo showed a pooled VR of 0.99 (95% CI:0.87-1.14), which suggests a homogeneous HVPG response to NSBB at the individual patient level (ie, no evidence to support that some patients responded to beta-blockers and others did not). For the comparison between carvedilol and propranolol, pooled VR was 0.97 (95% CI 0.82-1.14), suggesting that carvedilol achieves a greater average response (rather than an increase in the proportion of responders). There was no evidence of a heterogeneous response to statins.

CONCLUSION

Our analysis did not support the existence of a heterogeneous patient-by-patient response to NSBBs in cirrhosis. These findings challenge the concept of personalized therapy based on portal pressure response and indicate that routine portal pressure measurement may not be necessary to guide NSBB therapy.

Cirrhotic Multiorgan Syndrome

Patients with cirrhosis and portal hypertension are at an increased risk of the development of circulatory dysfunction that may potentially result in multiple organ failure. Apart from the liver, this may involve the heart, lungs, kidneys, the immune system, the adrenal glands, and other organ systems. As the disease progresses, the circulation becomes hyperdynamic, and signs of cardiac, pulmonary, and renal dysfunction are observed, in addition to reduced survival. Infections and an altered cardiac function known as cirrhotic cardiomyopathy may be precipitators for the development of other complications such as hepatorenal syndrome. In patients with chronic organ dysfunction, various precipitating events may induce an acute-on-chronic renal failure and acute-on-chronic liver failure that negatively affect the prognosis. Future research on the pathophysiologic mechanisms of the complications and the precipitating factors is essential to understand the basics of the treatment of these challenging conditions. The aim of the present review is to focus on the development and precipitating factors of various organ failures in patients with decompensated cirrhosis.

A pilot study of capsule endoscopy after a standard meal for the detection and grading of oesophageal varices in cirrhotic patients

BACKGROUND

Capsule endoscopy has been proposed as an alternative to fibreoptic endoscopy for oesophageal varices evaluation in cirrhotics. However, it shows only moderate sensitivity compared to fibreoptic endoscopy.

AIM

To compare post-meal capsule endoscopy to fibreoptic endoscopy, based on the hypothesis that meal-induced increase of portal pressure can enhance its sensitivity.

METHODS

Twenty-five patients were submitted to fibreoptic endoscopy and, after a standard meal, capsule endoscopy.

RESULTS

Post-meal capsule endoscopy detected varices in the 18 patients in whom fibreoptic endoscopy detected varices plus 3 more subjects (sensitivity 100%, specificity 70%); large varices in the 4 patients in whom fibreoptic endoscopy graded varices as large, plus 5 more subjects; red markers in the 5 patients in whom fibreoptic endoscopy detected red markers, plus 3 more subjects. High-risk varices were identified in 11 patients by post-meal capsule endoscopy and in 10 by fibreoptic endoscopy (sensitivity 100%, specificity 93.8%).

CONCLUSIONS

Post-meal capsule endoscopy identified more varices, large varices and red markers than fibreoptic endoscopy. The two methods detected similar proportions of high-risk varices. These data suggest that a standard meal can enhance the sensitivity of capsule endoscopy in the detection and grading of oesophageal varices in cirrhotics.

Food intake increases liver stiffness measurements and hampers reliable values in patients with chronic hepatitis B and healthy controls: the PROLIFICA experience in The Gambia

BACKGROUND

By increasing the hepatic blood circulation, food intake has been suggested to increase liver stiffness measurement (LSM) values in HCV-infected patients.

AIM

To investigate prospectively the effects of food intake on LSM in hepatitis B virus (HBV)-infected patients and healthy controls.

METHODS

In The Gambia, patients included in the PROLIFICA project are screened for HBV at the community level and then invited for fasting assessment including LSM. Between April 2012 and October 2012, each day, the first five participants were invited to participate in this study. After the initial examination, a standardised 850 Kcal breakfast was provided. Effect of food intake was assessed by examining mean difference of LSM, IQR and IQR/LSM at T0 (fasting LSM1), T30min (LSM2) and T120min (LSM3) respectively.

RESULTS

A total of 209 subjects were enrolled in this study (133 were HBV positive, 76 healthy controls). Unreliable measurements occurred more frequently after food intake (5%, 24% and 18% at T0, T30min and T120min respectively). In both groups, median LSM2 was significantly higher than LSM1 [6.2 (IQR: 5.4, 7.9)] vs. 4.9 (4.2, 6.2), P < 0.0001. LSM3 was still higher than the baseline, but lower than LSM2. In multivariable analysis, no factor modified the effect of breakfast on LSM. In a subgroup of patients having liver biopsies, we confirmed that food intake can overestimate liver fibrosis.

CONCLUSIONS

Food intake significantly increases liver stiffness measurement and its IQR values in patients with chronic hepatitis B as well as healthy individuals; and also the number of unreliable liver stiffness measurement values.

Indications for portal pressure measurement in chronic liver disease

Portal hypertension leads to development of serious complications such as esophageal varices, ascites, renal and cardiovascular dysfunction. The importance of the degree of portal hypertension has been substantiated within recent years. Measurement of the portal pressure is simple and safe and the hepatic venous pressure gradient (HVPG) independently predicts survival and development of complications such as ascites, HCC and bleeding from esophageal varices. Moreover, measurements of HVPG can be used to guide pharmacotherapy for primary and secondary prophylaxis for variceal bleeding. Assessment of HVPG should therefore be considered as a part of the general characterization of patients with portal hypertension in departments assessing and treating this condition.

The extent of the collateral circulation influences the postprandial increase in portal pressure in patients with cirrhosis

BACKGROUND

In cirrhosis, repeated flares of portal pressure and collateral blood flow provoked by postprandial hyperaemia may contribute to variceal dilation and rupture.

AIM

To examine the effect of the extent of the collateral circulation on the postprandial increase in portal pressure observed in cirrhosis.

PATIENTS AND METHODS

The hepatic venous pressure gradient (HVPG), hepatic blood flow and azygos blood flow were measured in 64 patients with cirrhosis before and after a standard liquid meal.

RESULTS

Peak increases in HVPG (median+14.9%), hepatic blood flow (median+25.4%), and azygos blood flow (median+32.2%) occurred at 30 min after the meal. Compared with patients with marked postprandial increase in HVPG (above the median, n = 32), those showing mild (<15%, n = 32) increase in HVPG had a higher baseline azygos flow (p<0.01) and underwent a greater postprandial increase in azygos flow (p<0.02). Hepatic blood flow increased similarly in both groups. Postprandial increases in HVPG were inversely correlated (p<0.001) with both baseline azygos flow (r = -0.69) and its postprandial increase (r = -0.72). Food intake increased nitric oxide products in the azygos (p<0.01), but not in the hepatic vein. Large varices (p<0.01) and previous variceal bleeding (p<0.001) were more frequent in patients with mild increase in HVPG.

CONCLUSIONS

Postprandial hyperaemia simultaneously increases HVPG and collateral flow. The extent of the collateral circulation determines the HVPG response to food intake. Patients with extensive collateralisation show less pronounced postprandial increases in HVPG, but associated with marked flares in collateral flow. Collateral vessels preserve their ability to dilate in response to increased blood flow.

Effect of meal and propranolol on whole body and splanchnic oxygen consumption in patients with cirrhosis

Our aim was to measure whole body energy expenditure after a mixed liquid meal, with and without simultaneous propranolol infusion, in patients with cirrhosis. We also wanted to investigate the effect of propranolol on substrate fluxes and oxygen uptake in the tissues drained by the hepatic vein and azygos vein in the postprandial period in these patients. Whole-body oxygen uptake, hepatic blood flow, hepatic venous pressure gradient and net-hepatic fluxes of oxygen, lactate, glucose, glycerol, and free fatty acids (FFA) were measured in 12 patients with alcoholic cirrhosis before and for 2 h after ingestion of a mixed liquid meal (700 kcal). Half of the patients (n = 6) were randomized to a treatment group receiving intravenous infusion of propranolol in combination with the meal. The meal-induced energy expenditure was significantly lower in patients given propranolol [15.0 +/- 18.9 vs. 67.0 +/- 26.1 kJ/120 min (means +/- SD), P < 0.01]. Meal-induced whole body oxygen uptake was lower in patients receiving propranolol (19.2 +/- 38 vs. 135.7 +/- 61 mmol/120 min, P < 0.01), and the meal-induced increase in splanchnic oxygen uptake was nonexistent when propranolol was administered in combination (-13.2 +/- 34.8 vs. 110.4 +/- 34.8 mmol/120 min, P = 0.04). Postprandially, the propranolol group had a tendency toward a reduced splanchnic glucose output, and the FFA uptake was significantly reduced. Propranolol reduces meal-induced whole body oxygen uptake and energy expenditure as well as splanchnic oxygen uptake. The splanchnic reduction in oxygen consumption can explain almost the entire reduction in whole body oxygen consumption.

Current management of the complications of portal hypertension: variceal bleeding and ascites

Portal hypertension is one of the main consequences of cirrhosis. It results from a combination of increased intrahepatic vascular resistance and increased blood flow through the portal venous system. The condition leads to the formation of portosystemic collateral veins. Esophagogastric varices have the greatest clinical impact, with a risk of bleeding as high as 30% within 2 years of medium or large varices developing. Ascites, another important complication of advanced cirrhosis and severe portal hypertension, is sometimes refractory to treatment and is complicated by spontaneous bacterial peritonitis and hepatorenal syndrome. We describe the pathophysiology of portal hypertension and the current management of its complications, with emphasis on the prophylaxis and treatment of variceal bleeding and ascites.

Simvastatin enhances hepatic nitric oxide production and decreases the hepatic vascular tone in patients with cirrhosis

BACKGROUND & AIMS

In cirrhosis, an insufficient release of nitric oxide contributes to increased hepatic resistance and portal pressure and enhances the postprandial increase in portal pressure. We hypothesized that simvastatin, which enhances Akt-dependent endothelial nitric oxide synthase phosphorylation, may increase hepatic nitric oxide release and decrease hepatic resistance in patients with cirrhosis and portal hypertension.

METHODS

In protocol 1, 13 patients had measurements of the hepatic venous pressure gradient, hepatic blood flow, mean arterial pressure, cardiac output, and nitric oxide products before and 30 and 60 minutes after 40 mg of simvastatin. In protocol 2, 17 patients were randomized to receive placebo or simvastatin (40 mg) 12 hours and 1 hour before the study. After baseline measurements of the hepatic venous pressure gradient, hepatic blood flow, and nitric oxide products, a standard liquid meal was given, and measurements were repeated at 15, 30, and 45 minutes.

RESULTS

In protocol 1, acute simvastatin did not modify the hepatic venous pressure gradient but increased the hepatic blood flow (21% +/- 13% at 30 minutes; P = 0.01) and decreased hepatic sinusoidal resistance by 14% +/- 11% (P = 0.04). Nitric oxide product levels significantly increased in hepatic venous blood (from 31.4 +/- 12.3 nmol. mL(-1) to 35.8 +/- 10.7 nmol. mL(-1); P = 0.04), but not in peripheral blood. Systemic hemodynamics were not modified. In protocol 2, simvastatin pretreatment significantly attenuated the postprandial increase in hepatic venous pressure gradient (mean peak increase, 10% +/- 9% vs. 21% +/- 6% in placebo; P = 0.01). Hepatic blood flow increased similarly in the 2 groups. Hepatic nitric oxide products increased in the simvastatin group but not in the placebo group.

CONCLUSIONS

Simvastatin administration increases the hepatosplanchnic output of nitric oxide products and decreases hepatic resistance in patients with cirrhosis.

Low doses of isosorbide mononitrate attenuate the postprandial increase in portal pressure in patients with cirrhosis

Postprandial hyperemia is associated with a significant increase in portal pressure in cirrhosis, which may contribute to progressive dilation and rupture of gastroesophageal varices. In cirrhosis, an insufficient hepatic production of nitric oxide (NO) may impair the expected hepatic vasodilatory response to increased blood flow, further exaggerating the postprandial increase in portal pressure. This study was aimed at investigating whether low doses of an oral NO donor might counteract the postprandial peak in portal pressure. Twenty-three portal hypertensive cirrhotics, 8 of them under propranolol therapy, were randomized to receive orally 5-isosorbide mononitrate (ISMN; 10 mg; n = 11) or placebo (n = 12) and a standard liquid meal 15 minutes later. Hepatic venous pressure gradient (HVPG), mean arterial pressure (MAP), and hepatic blood flow (HBF) were measured at baseline and 15, 30, and 45 minutes after a meal. ISMN significantly attenuated the postprandial increase in portal pressure as compared with placebo (peak HVPG increase: 2.4 +/- 1.4 mm Hg vs. 5.2 +/- 2.1 mm Hg, P =.002). Percentual increases in HBF were similar in both groups. MAP decreased slightly in ISMN group (-7.5% +/-.5%; P <.01 vs. baseline). These effects were also observed in patients on chronic propranolol therapy. In conclusion, hepatic NO supplementation by low doses of ISMN effectively reduces the postprandial increase of portal pressure in cirrhosis, with only a mild effect on arterial pressure. The same was observed in patients receiving propranolol. Our results suggest that therapeutic strategies based on selective hepatic NO delivery may improve the treatment of portal hypertension.

Increasing intra-abdominal pressure increases pressure, volume, and wall tension in esophageal varices

Many daily activities cause acute elevations of intra-abdominal pressure (IAP). In portal hypertensive cirrhotic patients, increased IAP increases absolute portal pressure and azygos blood flow, suggesting that it may have detrimental consequences at the esophageal varices. The aim of this study was to investigate the effects of increased IAP on variceal pressure, size, and wall tension. Endosonography and a noninvasive endoscopic pressure gauge were used to measure variceal pressure, radius, wall tension, and volume in baseline conditions and after increasing IAP by 10 mm Hg using an inflatable girdle in 14 patients with cirrhosis and esophageal varices. Increasing IAP markedly increased variceal pressure (from 13.3 +/- 4.2 to 17.4 +/- 4.6 mm Hg; P =.0001) and radius (from 2.9 +/- 1.0 to 3.9 +/- 1.1 mm; P =.0001). Consequently, wall tension dramatically increased (from 38.7 +/- 13.6 to 65.9 +/- 23.8 mm Hg. mm, +78%; P =.0001). Variceal volume increased significantly from 1,264 +/- 759 to 2,025 +/- 1,129 mm(3) (P =.0001). In conclusion, in portal hypertensive cirrhotic patients, increases in IAP have deleterious effects on variceal hemodynamics, markedly increasing the volume, pressure, and wall tension of the varices. Increases in IAP may contribute to the progressive dilatation that precedes the rupture of the varices in portal hypertension.

Effects of long-term propranolol and octreotide on postprandial hemodynamics in cirrhosis: a randomized, controlled trial

BACKGROUND & AIMS

Postprandial increases in portal pressure may influence esophageal variceal rupture. The effects of chronic propranolol and octreotide (100 and 200 microg subcutaneously in a single dose) on postprandial hemodynamics were evaluated.

METHODS

FIRST STUDY: 36 cirrhotic patients were studied at baseline and 30 and 60 minutes after a standard meal and then treated with propranolol (139 +/- 9 mg/d during 39 +/- 2 days). SECOND STUDY: After baseline measurements, patients were randomized into 3 groups: (1) placebo, (2) octreotide (100 microg), or (3) octreotide (200 microg) (n = 12 for each group). Thirty minutes postinjection a new baseline was established and measurements were repeated 30 and 60 minutes after the meal.

RESULTS

First study: Baseline portal pressure was 18.1 +/- 1.2 mm Hg, 30 and 60 minutes after the meal it was 21.5 +/- 0.8 mm Hg and 20.5 +/- 0.8 mm Hg, respectively (both P < 0.01 vs. baseline). Cardiac index (CI) was 4.5 +/- 0.2, 4.8 +/- 0.2, and 4.9 +/- 0.2 L x min(-1) x m(-2), respectively (both P < 0.05 vs. baseline). Peripheral vascular resistance was 1012 +/- 56, 902 +/- 51 (P = NS), and 884 +/- 49 dynes x sec x cm(-5) (P< 0.05 vs. baseline), respectively. Second study: Propranolol and placebo did not blunt postprandial increase in portal pressure. Octreotide (100 microg) partially ameliorated postprandial increase in portal pressure. Octreotide (200 microg) significantly enhanced the portal hypotensive effect of propranolol and blunted the postprandial increase in portal pressure.

CONCLUSIONS

Octreotide blunts postprandial increase in portal pressure not prevented by long-term propranolol administration.

Octreotide ameliorates the increase in collateral blood flow during postprandial hyperemia in portal hypertensive rats

BACKGROUND/AIMS

The aims of this study were to examine, in a conscious rat model of portal hypertension, the effect of postprandial splanchnic hyperemia on collateral blood flow and to determine whether octreotide has an effect on postprandial collateral flow changes.

METHODS

In rats with portal vein ligation, pulsed-Doppler flowmeters were implanted chronically around the splenorenal venous shunt (SRS), which is the main spontaneous collateral vessel in the portal hypertensive rat and around the superior mesenteric artery (SMA). Changes in flow after a standard liquid meal gavage and after the administration of octreotide were examined in the rat under unanesthetized and unrestricted conditions.

RESULTS

SRS flow increased significantly after gavage with a standard liquid meal (10.6+/-2.9%) compared to orogastric intubation alone (-6.5+/-2.1%) (P<0.01). Similar flow changes were observed in the SMA after liquid meal gavage. The subcutaneous administration of octreotide at a dose of 400 g/kg reduces basal SRS flow (-19.5+/-2.3%) and significantly attenuated the change in SRS flow after liquid meal gavage (-8.1+/-2.9%) compared to animals that received placebo (3.6+/-4.1% and 27.8+/-7.6%, respectively) (P<0.05).

CONCLUSION

These results demonstrate that, in an experimental model of prehepatic portal hypertension, postprandial splanchnic hyperemia results in an increase in collateral flow that can be ameliorated with the use of octreotide.

Management of portal hypertension after variceal hemorrhage

Each variceal bleed is associated with 20% to 30% risk of dying. Management of portal hypertension after a bleed consists of (1) control of bleeding and (2) prevention of rebleeding. Effective control of bleeding can be achieved either pharmacologically by administering somatostatin or octreotide or endoscopically via sclerotherapy or variceal band ligation. In practice, both pharmacologic and endoscopic therapy are used concomitantly. Rebleeding can be prevented by endoscopic obliteration of varices. In this setting, variceal ligation is the preferred endoscopic modality. B-blockade is as effective as endoscopic therapy and, in combination, the two modalities may be additive.

Haemodynamic effects of propranolol, octreotide and their combination during fasting and post-prandial splanchnic hyperaemia in patients with cirrhosis

BACKGROUND/AIMS

This double-blind study was designed to evaluate the haemodynamic effect of two drugs, propranolol and octreotide, and their combination in patients with cirrhosis.

METHODS

Fifteen patients with cirrhosis were randomly assigned to two groups receiving either octreotide subcutaneously at 100 microg ('octreotide' group, n = 9) or propranolol orally at 40 mg followed by a subcutaneous dose of octreotide (100 microg) after 1 h ('propranolol + octreotide' group, n = 6); then, after 30 min, a standard meal was administered to both groups. The hepatic vein pressure gradient by hepatic vein catheterization, portal and superior mesenteric artery blood flow velocity, superior mesenteric artery pulsatility index by the echo-Doppler duplex system were recorded at baseline, 1 h after propranolol in the 'propranolol + octreotide' group, and in both groups 30 min after octreotide and 30 min after meal.

RESULTS

At fast, propranolol was more active in decreasing portal pressure (from 16 +/- 2.2 to 12.7 +/- 3.8 mmHg, -20%, P < 0.05) as compared to octreotide (from 18.6 +/- 4.8 to 16.6 +/- 4.3 mmHg, -11%, P < 0.05). Conversely, octreotide was more active on the mean blood flow velocity of superior mesenteric artery (from 22.8 +/- 5 to 19 +/- 4.5 cm/ s, -17%; P< 0.05). Octreotide administration in patients receiving beta-blockers showed, also, a trend to increase the mesenteric vascular resistances (pulsatility index from 3.14 +/- 0.69 to 3.68 +/- 1.29, +17%, not significant (NS)) which had not been affected by previous treatment with propranolol. After the meal, a reduction of the expected hyperaemic response occurred in both groups.

CONCLUSIONS

The combined acute haemodynamic effect of this association suggests the possible combination of these two drugs in critical situations, such as variceal bleeding in patients receiving beta-blockers. The simultaneous use of echo-Doppler and hepatic vein catheterization permitted us a more complete analysis of the acute haemodynamic events.

Influence of esophageal varices and spontaneous portal-systemic shunts on postprandial splanchnic hemodynamics

OBJECTIVE

The aim of the study was to assess postprandial splanchnic hemodynamic changes in cirrhosis in relation to variceal status.

METHODS

In 9 healthy controls and 56 patients with liver cirrhosis, stratified according to variceal status and presence of spontaneous portal-systemic shunts, the portal vein diameter and flow velocity, the congestion index of the portal vein, and the resistive index of the superior mesenteric artery (SMA-RI) were studied by Doppler ultrasound before and 30, 60, and 120 min after the intake of a standard meal. Comparison of postprandial parameters with basal ones was done within each group by paired t test and among groups by ANOVA and Duncan test.

RESULTS

Healthy controls and cirrhotic patients without varices showed similar significant splanchnic hemodynamic changes, namely a reduction of SMA-RI (-13% at 30 min) and a consequent increase in portal vein diameter (respectively, +32% and +17% in the two groups) and velocity (+66% and +51%). A significant reduction of SMA-RI was also found in patients with varices, irrespective of the variceal size (range, -7 to -11%), but the expected portal vein dilation and velocity increase were progressively blunted with the increase of variceal size (range, 0-5% for diameter and 5-19% for velocity). Patients with spontaneous portal-systemic shunts showed a response similar to that of patients with large varices. Significant modification of the congestion index of the portal vein did not occur in any group.

CONCLUSIONS

Our results show that the hemodynamic response to meal in patients with liver cirrhosis is influenced by the presence and size of esophageal varices and the presence of spontaneous portal-systemic shunts.

Esophageal varices. I. Clinical presentation, medical therapy, and endoscopic therapy

The last half century has witnessed great advances in the understanding of the pathogenesis and natural history of portal hypertension in cirrhotics. Several pharmacologic and endoscopic techniques have been developed for the treatment of portal hypertension. The use of these agents in a given patient must be based on an understanding of the stage in the natural history of the disease and the relative efficacy and safety of the available treatment options.

Mesenteric blood flow is related to disease activity and risk of relapse in Crohn's disease: a prospective follow-up study

OBJECTIVE

The diagnostic significance of increased splanchnic blood flow in Crohn's disease is unclear. This prospective study was therefore undertaken to define the role of Doppler sonography in the assessment of disease activity and in the prediction of early relapse.

METHODS

Splanchnic flowmetry was performed in 59 patients with Crohn's disease and 20 healthy volunteers during fasting and 30 min after ingestion of a standardized meal. Twenty-one patients measured during the active state and in clinical remission were followed-up for 6 months. Hemodynamic parameters of the superior and inferior mesenteric arteries and the portal vein were related to clinical (Crohn's disease activity index [CDAI]), laboratory (C-reactive protein), and endoscopic (Crohn's Disease Endoscopic Index of Severity) parameters of disease activity.

RESULTS

The postprandial mean velocity of the superior mesenteric artery correlated closest with clinical activity (CDAI, p < 0.005) and C-reactive protein (p < 0.01), but was unrelated to endoscopic activity. All patients in remission after 6 months (9/9) showed an increase in postprandial pulsatility index of the superior mesenteric artery, compared with an initial measurement during active disease (+28%). In contrast, the majority of patients with later relapse or surgery (11/12) had decreased pulsatility index during initial remission (-20%). The positive predictive value of this index for maintenance of remission was 0.82.

CONCLUSIONS

Postprandial flow measurements in the superior mesenteric artery are closely related to clinical but not endoscopic disease activity in patients with Crohn's disease. The repeated measurement of the postprandial pulsatility index allows estimation of the risk of recurrence.

Long-term haemodynamic effects of octreotide on postprandial splanchnic hyperemia in humans: a placebo-controlled echo-doppler study

BACKGROUND

Octreotide is a potent splanchnic hypotensive somatostatin analogue effective in the treatment of acute variceal bleeding.

AIM

To study the effects of octreotide on basal and postprandial splanchnic and systemic haemodynamics, and hormonal changes in humans.

METHODS

Twenty-four healthy volunteers were randomized to receive a liquid meal and either octreotide (OCT, 100 microg bolus) or placebo repeatedly every 4 h for 48 h. Splanchnic (Doppler ultrasound) and systemic haemodynamics (non-invasive cardiac monitoring) were assessed for 2 h on four consecutive days: one control day and after doses 1 (0 h), 7 (24 h) and 13 (48 h).

RESULTS

The maximum postprandial increases in mean blood velocity of the superior mesenteric artery (SMA-Vmean +72%), portal (PBF +52%) and total hepatic blood flow (HBF +50%) observed in the placebo group, were abolished after the first dose of octreotide (SMA-Vmean -23%, P<0.01; PBF -22%, P<0.01; HBF -21%, P<0.01). Postprandial hyperemia was restored at the end of the 48-h study period, but baseline SMA-Vmean (placebo 40+/-12, OCT 29+/-11 cm/s, P<0.05) and PBF (placebo 1200+/-971, OCT 743+/-449 mL/min, P<0.05) remained significantly lower in the octreotide group. The postprandial decrease of systemic vascular resistance and increase of cardiac index were prevented by octreotide for 48 h.

CONCLUSIONS

Repeated 4-hourly bolus injections of octreotide reduce splanchnic blood flow for at least 48 h, but the prevention of food-induced splanchnic hyperemia is short-lasting.

The postprandial portal flow is related to the severity of portal hypertension and liver cirrhosis

BACKGROUND/AIMS

Diminished postprandial portal hyperemia has been demonstrated by echo-Doppler flowmetry in patients with liver cirrhosis, but its diagnostic role is unclear. This prospective study was therefore undertaken in patients with varying severity of portal hypertension and degree of liver cirrhosis.

METHODS

Portal flowmetry was performed in 66 patients with cirrhosis and 20 healthy volunteers during fasting and 30 min after ingestion of a standardized meal. Hemodynamic parameters were related to the degree of esophageal varices, variceal bleeding, portal hypertensive gastropathy and Child-Pugh score.

RESULTS

The postprandial portal blood velocity increment was low in patients with esophageal varices of any degree (22-24%), compared to patients without varices (49%, p<0.01) and healthy controls (65%, p<0.001), but was not different in patients with or without variceal bleeding (22% vs. 20%). In contrast, the congestion index (CI; ratio of portal vein cross-sectional area and portal blood velocity) pre-/postprandial decreased in the bleeding group only (CI pre/ CI post 1.30+/-0.23 (no bleeding) vs. 0.86+/-0.29 (bleeding); p<0.01). Portal hypertensive gastropathy was not related to any of the portal flow parameters. The portal blood velocity increment was comparable in controls (65%) and patients with Child-Pugh class A cirrhosis (56%), but lower in patients with class B (32%) and class C cirrhosis (15%, p<0.05 vs. class A). Also, there was no postprandial decrease in congestion index in patients with the most severe cirrhosis (p<0.01 class C vs. class A and B).

CONCLUSIONS

The postprandial rise in portal flow is inversely related to the severity of portal hypertension and liver cirrhosis, and may be a valuable parameter with respect to the risk of variceal bleeding.

Blunted postprandial reaction of portal venous flow in chronic liver disease, assessed with duplex Doppler: significance for prognosis

To establish the effects of a meal on portal venous flow and the prognostic value of this parameter, 46 patients with chronic liver disease and 28 healthy subjects were examined with duplex Doppler before and after a meal. The measurements were completed in 40 patients and 21 healthy subjects. Postprandial portal venous diameter, blood velocity and quantitative flow were measured for 60 min. Mean baseline values were: 11.4 mm versus 10.2 mm (p = 0.019), 10.8 cm.s-1 versus 13.4 cm.s-1 (p = 0.015) and 668 ml.min-1 versus 646 ml.min-1 (p = 0.7) respectively. Spleen size was 15.0 cm versus 10.6 cm (p = 0.0001) respectively. Postprandial diameter, velocity and flow increased significantly in patients and controls (p = 0.0001 for all). Mean postprandial flow could best be described by a polynomial equation with a parabolic curve. Patients' curves were more blunted than controls', with significantly different regression constants (p = 0.025 and p = 0.029). All subjects were followed up for survival and variceal haemorrhage. The mean follow-up time was 47 months. Early maximum postprandial velocity (p = 0.041) and large spleen size (p = 0.002) were significantly related to an unfavourable prognosis for survival. Early maximum velocity was also related to increased variceal haemorrhage. This study shows that postprandial portal venous flow is blunted in patients with chronic liver disease. Postprandial portal venous flow may have prognostic significance.

Effects of octreotide on postprandial systemic and hepatic hemodynamics in patients with postnecrotic cirrhosis

The effects of octreotide on postprandial hemodynamic responses were evaluated in 20 patients with postnecrotic cirrhosis. They were randomly assigned to receive either a 100-micrograms bolus with a 100-micrograms/h infusion of octreotide or a placebo. Placebo administration did not affect any of the hemodynamic values. However, after a liquid meal of 500 kcal, postprandial increases in the hepatic venous pressure gradient and hepatic blood flow were observed in patients receiving placebo, while the systemic hemodynamic values remained unchanged. In contrast, in patients receiving octreotide, the hepatic blood flow was significantly decreased 30 min after administration, while the hepatic venous pressure gradient and the systemic hemodynamic values were not affected. After ingestion of a meal, the mean values of the hepatic blood flows were not significantly different from basal values. Moreover, the wedged hepatic venous pressure, the hepatic venous pressure gradient and the systemic hemodynamic values were not affected by meal ingestion. However, during octreotide infusion, hepatic blood flow 30 min after the meal had a tendency to increase compared to before the meal. In conclusion, octreotide inhibited the postprandial increase in portal pressure in patients with postnecrotic cirrhosis. In addition, octreotide decreased hepatic blood flow in the fasting state. When given before a meal, the increase in blood flow induced by the meal restored the hepatic blood flow to basal levels.

Octreotide prevents postprandial splanchnic hyperemia in patients with portal hypertension

An increase in splanchnic blood flow is a physiological response to food intake. In patients with cirrhosis whose hepatic vascular resistance is already high, this increase in flow leads to marked increases in portal pressure. This study investigates whether octreotide prevents the increases in hepatic flow and portal pressure that follow the ingestion of a meal in patients with cirrhosis. Twenty-two patients with cirrhosis and portal hypertension were randomized to receive a mixed liquid meal (520 kcal) plus a single subcutaneous injection of either placebo or octreotide (200 micrograms). In the placebo group the ingestion of a meal was followed by an increase in the hepatic venous pressure gradient (+ 19.4 +/- 4.3%, p < 0.01) and hepatic blood flow (+ 38.2 +/- 14.6%, p < 0.05) at 30 min. In contrast, in the octreotide group eating caused no significant change in the hepatic venous pressure gradient (-2.8 +/- 3.6%, NS), while hepatic flow was decreased (-6.08 +/- 5.4%, p < 0.05). Octreotide blunted the postprandial increase in serum insulin and glucagon levels observed in the placebo group. In conclusion, in patients with cirrhosis and portal hypertension, octreotide prevents the postprandial increase in hepatic blood flow, and consequently also in portal pressure. These findings suggest that this drug could play a role in the long-term management of portal hypertension.

Postprandial vascular response in patients with cirrhosis. Short-term effects of propranolol administration

Systemic and portal hemodynamic parameters were evaluated in eight cirrhotic patients in basal conditions and after food intake and placebo. Following seven days of oral propranolol administration, hemodynamic parameters were reevaluated in the fasting and postprandial states under similar conditions. Cardiac output and portal blood flow were measured by Doppler technique. Intraobserver variability of repeated measurements was less than 10%. Food intake caused a significant increase of portal blood flow (+28%, P < 0.05). No significant changes were observed in the other hemodynamic parameters studied. Propranolol at doses achieving effective beta blockade (84 +/- 14 mg/day) (mean +/- SD) reduced portal blood flow (-24%, P < 0.05). Food intake caused a significant increase in portal blood flow (+35%, P < 0.05) in propranolol treated patients. However, in absolute values, postprandial portal blood flow during propranolol treatment was significantly lower (986 +/- 402 ml/min) than that obtained after the initial food intake (1214 +/- 537 ml/min, P < 0.05). Placebo administration had no significant hemodynamic effects in either group. This study demonstrates that chronic propranolol administration could protect from portal hemodynamic changes following food intake. Doppler technique is a reliable technique to evaluate changes on portal and systemic hemodynamic parameters during a short period of time in patients with cirrhosis.

Meal induced changes in hepatic and splanchnic circulation: a noninvasive Doppler study in normal humans

The haemodynamic effects of a meal on the splanchnic and hepatic circulation were evaluated in 30 healthy volunteers, using Doppler ultrasonography. The resistance index (RI) of the superior mesenteric artery and of the left and right intrahepatic arteries, the portal vein blood flow as well as the ratio between maximal velocity in the left and right intrahepatic arteries and the adjacent portal vein were measured initially, then 15, 30, 45, and 60 min after the ingestion of a standard balanced liquid meal. Postprandial haemodynamic changes were maximal 30 min after the meal; at that time, mesenteric artery RI decreased significantly [mean -11% (SEM 14%)] whereas portal vein blood flow increased markedly [mean +79% (SEM 14%)]; a significant increase in hepatic artery RI was observed in both liver lobes. The ratio between maximal velocities of the intrahepatic artery and the intrahepatic portal vein was reduced significantly; this ratio decreased more markedly in the right lobe of the liver. These findings would suggest that there was an adaptation of hepatic artery to portal vein blood flow after a meal. The subsequent increase in intrahepatic portal vein flow velocity was found to be greater in the right lobe of the liver.

Pharmacological treatment of portal hypertension: hemodynamic effects and prevention of bleeding

In the past 10 years, it has been clearly shown that vasoactive substances reduce portal pressure in patients or animals with portal hypertension. Some of these substances act by inducing splanchnic vasoconstriction, while others reduce hepatic and porto-systemic collateral vascular resistance and, thus, induce a portal hypotensive effect. Still others induce arterial hypotension, which causes a vasoconstrictive effect in the splanchnic territory. Since these drugs act on different vascular receptors, their combination should have a more marked effect on portal hypertension. Up to now, only nonselective beta-blockers have been used in the prevention of first gastrointestinal bleeding in patients with portal hypertension and esophageal varices and in the prevention of recurrent gastrointestinal bleeding. These trials have shown that propranolol or nadolol significantly reduce either a first episode of bleeding or recurrent bleeding. This pharmacological treatment also improves the survival rate in these patients. All of these studies have helped us to understand, in part, why gastrointestinal hemorrhage occurs in certain patients. Additional studies of beta-blockers or other substances are, nevertheless, necessary to select patients who will respond to this type of treatment. Finally, it is possible that the pharmacological treatment of portal hypertension may also be used before esophageal varices occur.