Effect of propranolol on portosystemic collateral circulation in patients with cirrhosis

Aspectos ultra-sonográficos da trombose da veia porta

A trombose da veia porta pode estar associada a várias alterações, como a presença de tumores (por exemplo: hepatocarcinoma, doença metastática hepática e carcinoma do pâncreas), pancreatite, hepatite, septicemia, trauma, esplenectomia, derivações porto-cava, estados de hipercoagulabilidade (por exemplo: gravidez), em neonatos (por exemplo: onfalite e cateterização da veia umbilical) e desidratação aguda. Os autores discutem, neste artigo, os aspectos ultra-sonográficos da trombose de veia porta e alguns aspectos de relevância clínica.

Estudo Doppler na hipertensão portal

A ultra-sonografia e o Doppler representaram grande marco no diagnóstico da hipertensão portal. Este fato decorre do aspecto não-invasivo destes métodos, possibilitando o estudo do fígado, do baço e da circulação esplâncnica. Neste artigo os autores discutem alguns aspectos importantes avaliados pela ultra-sonografia e pelo Doppler na avaliação da hipertensão portal.

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.

Comparison of portal vein velocity and the hepatic venous pressure gradient in assessing the acute portal hemodynamic response to propranolol in patients with cirrhosis

OBJECTIVE

The aim of this prospective study was to compare noninvasive Doppler sonography and invasive measurement of the hepatic venous pressure gradient (HVPG) to determine the acute portal hemodynamic response to propranolol in patients with liver cirrhosis.

METHODS

In a blinded study design, portal vein velocity (PVV) and HVPG were simultaneously assessed in 11 cirrhotic patients for 4 h after oral ingestion of 40 mg propranolol.

RESULTS

Both HVPG (17.2% +/- 4.3%, p < 0.0001) and PVV (15.6% +/- 2.1%, p < 0.0002) showed a highly significant reduction during the study period versus baseline. Based on HVPG measurements, four patients (36%) were classified as nonresponders. These patients had a significantly lower PVV reduction compared to the responders (responders: 18.8% +/- 2.0% vs nonresponders: 10.0% +/- 2.1%, p < 0.05). Nonresponders were identified by Doppler sonography with a sensitivity of 1.0, specificity of 0.86, and positive predictive value of 0.9 when a threshold of 20% PVV reduction 120 min after drug intake was applied.

CONCLUSIONS

Doppler sonography is a useful tool for assessment of the acute portal hemodynamic effect of propranolol. To distinguish portal hemodynamic nonresponders from responders to propranolol, PVV measurements should be carried out 2 h after drug administration, and PVV reduction should be not <20% in propranolol responders.

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.

Doppler evaluation of the effects of pharmacological treatment of portal hypertension

The splanchnic pharmacodynamic effects of the drugs used for the treatment of hemorrhagic complications of portal hypertension were poorly clarified until some years ago. The introduction of Doppler ultrasound provided a powerful tool to investigate such hemodynamic effects and brought new insights in this field. The present article reviews the pharmacodynamics of the substances used in the treatment of portal hypertension, with particular regard to the effects assessable by duplex Doppler ultrasonography.

Prevention of first variceal bleed: an appraisal of current therapies

Primary prophylaxis of esophageal variceal hemorrhage (EVH) is an important issue in the management of patients with portal hypertension. Given the high rates of initial variceal hemorrhage and mortality in patients who have not experienced bleeding from varices, there is an urgent need for some form of primary prophylaxis in all patients with large esophageal varices. The aim of this article is to review the various therapies that have been clinically assessed in randomized controlled trials for their efficacy in prevention of initial EVH. Beta-blockers have been found to be useful in primary prophylaxis of EVH, and the consensus at present is that they should be offered to all patients with portal hypertension who are at high risk for EVH. Nitrates and other newer agents are under evaluation. Surgery is not recommended for primary prophylaxis of EVH. Endoscopic sclerotherapy has not been shown unequivocally to be efficacious, and may even be deleterious, possibly related to an unacceptably high complication rate in this clinical setting. However, it may merit further clinical evaluation in light of recent reports of benefit in certain subgroups of patients with portal hypertension. On the other hand, endoscopic variceal ligation, which has an inherently low complication rate and brings about rapid obliteration of varices, may be a better option for primary prophylaxis of EVH. In the future, preprimary prophylaxis, an attractive concept, may be considered. This would involve intervention with pharmacologic agents even before the development of portal hypertension or esophageal varices.

Noninvasive hemodynamic measurements of superior mesenteric artery in the prediction of portal pressure response to propranolol

BACKGROUND/AIMS

The portal pressure response to propranolol administration is heterogeneous in patients with cirrhosis. The aim of this study was to examine the diagnostic accuracy of noninvasive hemodynamic parameters of superior mesenteric artery (SMA) and femoral artery (FA) in the prediction of portal pressure response to propranolol.

METHODS

Twenty-six patients with cirrhosis were studied. Portal pressure was assessed by measurements of hepatic venous pressure gradient. Mean arterial pressure and heart rate were also recorded. Cardiac index, and flow velocity of SMA and FA, and pulsatility index of SMA and FA were then measured by means of Doppler ultrasonography. After intravenous propranolol administration (0.10 mg/kg), the above measurements were repeated.

RESULTS

Propranolol significantly reduced cardiac index, heart rate, SMA flow velocity, and FA flow velocity and increased SMA pulsatility index and FA pulsatility index. Although propranolol significantly decreased hepatic venous pressure gradient, a reduction of > or =20% was seen in only 10 patients (good responders); the remaining 16 patients exhibited <20% reduction (poor responders). No significant differences in clinical and baseline hemodynamic data were found in the two groups. There were no also significant differences in changes in heart rate and cardiac index. However, reductions in SMA and FA flow velocity were significantly greater in good responders than in poor responders. Although there was no the increase in FA pulsatility index, the increase in SMA pulsatility index was significantly greater in good responders than in poor responders. When appropriate cut-off points were determined for these variables, overall predictive values of SMA flow velocity (-20%) and SMA pulsatility index (+15%) were 91% and 83%, whereas the overall predictive value of FA flow velocity (-25%) was only 69%.

CONCLUSIONS

These results suggest that SMA flow velocity and SMA pulsatility index, but not FA flow velocity and FA pulsatility index, are useful noninvasive parameters in the prediction of portal pressure response to propranolol administration.

Duplex-Doppler evaluation of the effects of propranolol and isosorbide-5-mononitrate on portal flow and splanchnic arterial circulation in cirrhosis

BACKGROUND

A decrease in portal flow is an important pharmacological effect of drugs used for the prophylaxis of variceal bleeding.

AIM

To assess the acute and chronic effects of propranolol, and the effect of the acute addition of isosorbide-5-mononitrate, on splanchnic circulation.

METHODS

Measurements of portal blood flow volume (PBFV) and of Doppler ultrasound pulsatility index of the superior mesenteric, femoral and interlobar renal arteries were performed in 10 cirrhotic patients with varices at baseline, 90 min after propranolol or placebo, after 30 days of chronic propranolol treatment and 45 min after the addition of isosorbide-5-mononitrate.

RESULTS

The mean PBFV was significantly lower at all times than at baseline, with the greatest mean percentage decrease achieved after the addition of isosorbide-5-mononitrate (> or = 20% in all patients). Acute changes, however, did not predict the chronic effects in many patients. Isosorbide-5-mononitrate significantly increased the mesenteric and femoral pulsatility indices, whereas no significant change was observed in the kidney.

CONCLUSIONS

Propranolol significantly decreases PBFV, but chronic effects cannot be reliably predicted by the acute change. All patients achieved a decrease in PBFV of > or = 20% after the acute addition of isosorbide-5-mononitrate to chronic propranolol treatment.

Doppler sonography and hepatic vein catheterization in portal hypertension: assessment of agreement in evaluating severity and response to treatment

BACKGROUND/AIM

The study was designed to assess to what extent portal hemodynamic parameters obtained by duplex Doppler ultrasonography may be substituted for the measurement of hepatic venous pressure gradient in evaluating the severity of portal hypertension and the response to medical treatment with beta-blockers or beta-blockers plus nitrates in patients with cirrhosis and portal hypertension.

METHODS

In 39 of these patients hepatic venous pressure gradient was determined by hepatic vein catheterization, and portal blood flow velocity and the congestion index of the portal vein were measured by duplex Doppler ultrasonography. In 19 of these patients the changes in hepatic venous pressure gradient and in Doppler parameters were also assessed after chronic administration of nadolol. In 11 of the 19 patients the changes after chronic administration of nadolol plus isosorbide-5-mononitrate were also measured.

RESULTS

In the whole series, no significant correlation was found between hepatic venous pressure gradient and duplex Doppler parameters, but, when the 12 patients with a patent para-umbilical vein were excluded, significant linear correlations were found between hepatic venous pressure gradient and portal blood velocity (r=-0.39; p=0.05) or congestion index (r=0.37; p=0.05). Considering together the changes induced by nadolol and nadolol plus isosorbide-5-mononitrate, no correlation was apparent between changes in duplex Doppler parameters and in hepatic venous pressure gradient. Agreement between hepatic venous pressure gradient and duplex Doppler parameters in defining good and poor responders was insufficient.

CONCLUSIONS

These data suggest that portal blood velocity and the congestion index of the portal vein are related to portal hypertension in patients without a patent para-umbilical vein, but are of limited value in discriminating good responders from poor responders to medical treatment for portal hypertension.

Accuracy of portal and forearm blood flow measurements in the assessment of the portal pressure response to propranolol

BACKGROUND/AIMS

The portal pressure response to propranolol varies significantly in individual patients with cirrhosis. At present, propranolol responders can be identified only by measuring the hepatic venous pressure gradient. The aims of this study were: 1) to investigate whether the noninvasive monitoring of portal blood flow by pulsed Doppler ultrasound and forearm blood flow by strain-gauge plethysmography can predict the hepatic venous pressure gradient response to propranolol in patients with cirrhosis, and 2) to analyze the factors that may influence this response.

METHODS

Hemodynamic measurements were undertaken in 80 patients with cirrhosis before and after receiving propranolol (0.15 mg/kg i.v., n = 60) or placebo (n = 20).

RESULTS

No changes were observed in the placebo group. Propranolol lowered (p < 0.01) hepatic venous pressure gradient from 17.6 +/- 3.8 to 14.7 +/- 3.8 mmHg, portal blood flow from 1122 +/- 363 to 897 +/- 332 ml/min and forearm blood flow from 7.52 +/- 3.1 to 6.12 +/- 2.3 ml/min%. Changes in hepatic venous pressure gradient were correlated (p < 0.01) with those of portal blood flow (r = 0.82) and forearm blood flow (r = 0.54). The reduction in hepatic venous pressure gradient was > 20% in 23 patients ("responders"). The accuracy of portal Doppler flowmetry in identifying responders was higher than that of forearm plethysmography (88.3 vs. 68.3%, p < 0.05). Multivariate analysis proved that previous variceal bleeding was the only factor independently associated with a lack of response to propranolol (relative risk 3.42, 95% CI 1.5-7.4, p < 0.01). Hepatic venous pressure gradient reduction by propranolol was higher in non-bleeders than in bleeders (-19.9 +/- 9.4 vs. -11.3 +/- 8.6%, p < 0.01).

CONCLUSIONS

Portal Doppler ultrasound can be used as a reliable surrogate indicator of the hepatic venous pressure gradient response to acute propranolol administration. In addition, our study indicates that this response is mainly influenced by previous variceal hemorrhage.

Effects of chronic therapy with nadolol on portal hemodynamics and on splanchnic impedance indices using Doppler sonography: comparison between acute and chronic effects

BACKGROUND/AIMS

Beta-blockers are currently used for chronic therapy of portal hypertension. Duplex Doppler ultrasonography has been proposed for non-invasive evaluation of splanchnic pharmacodynamics, but the chronic effects of beta-blockers on portal hemodynamics and on splanchnic arterial impedance indices have not been analyzed with this method. This was the aim of the study.

METHODS

The effects of acute (80 mg p.o.) and chronic (2 months at a dosage sufficient to reduce heart rate by at least 25% in respect of basal values) nadolol administration on portal blood flow velocity and volume, and on splanchnic and renal arterial impedance indices [pulsatility index = (peak systolic velocity-minimum velocity)/mean velocity] were evaluated in patients with cirrhosis. Twenty-eight patients with cirrhosis and portal hypertension were investigated. Nineteen patients received nadolol, and nine received placebo.

RESULTS

Placebo caused no significant hemodynamic change. Portal blood flow mean velocity decreased after chronic therapy (11.7 +/- 2.9 cm/s to 9.1 +/- 2.3, p < 0.001). In the 16 patients with acute and chronic evaluation, portal blood flow mean velocity decreased after acute therapy (11.8 +/- 3.0 cm/s to 10.4 +/- 3.0, p < 0.01), and even more so after chronic therapy (to 9.2 +/- 2.4, p < 0.01). No parallel was found between acute and chronic effects. Hepatic, mesenteric and splenic pulsatility indices increased after chronic therapy (1.26 +/- 0.33 to 1.39 +/- 0.28, p < 0.02; 2.04 +/- 0.41 to 2.50 +/- 0.61, p < 0.01; 0.92 +/- 0.22 to 1.18 +/- 0.27, p < 0.001 respectively); renal pulsatility index increased (1.12 +/- 0.20 to 1.40 +/- 0.28, p < 0.001).

CONCLUSIONS

Chronic therapy with nadolol decreased portal blood flow velocity and volume, and increased splanchnic and renal impedance indices. Chronic effects of nadolol on portal inflow cannot be predicted from its acute effects. Evaluation of the effect of nadolol on portal blood velocity and volume should be performed after chronic therapy. Duplex Doppler ultrasonography allows venous and arterial splanchnic pharmacodynamics to be studied separately.

Distinctive portal venographic pattern in patients with sclerotherapy resistant oesophageal varices

We performed prophylactic sclerotherapy in 350 patients with 'high risk' oesophageal varices (F2 or F3 with a moderate or severe red colour sign). Of these patients, eight exhibited sclerotherapy resistance (i.e. no significant reduction in the size of varices after five sessions of sclerotherapy). Thus, the prevalence of sclerotherapy resistant varices was 2%. Of 350 patients, 97 underwent haemodynamic investigation before sclerotherapy. This group consisted of seven patients with sclerotherapy resistant varices and 90 patients with non-resistant varices. Portal pressure, assessed by portal venous pressure gradient, was similar in these two groups (21.5 +/- 4.8 vs 19.8 +/- 5.0 mmHg, respectively; NS). However, the prevalence of the 'pipe-line' form of variceal feeding pattern (a large dilated left gastric vein running up the oesophagus) was higher in patients with resistant varices than in those with non-resistant varices (100 vs 3%, respectively; P < 0.01) and the diameter of the left gastric vein was larger in patients with resistant varices than in those with non-resistant varices (12.4 +/- 2.0 vs 7.8 +/- 2.3 mm, respectively; P < 0.01). Moreover, the extravariceal portosystemic shunt was poorly developed in patients with resistant varices compared with non-resistant varices (0 vs 52%, respectively; P < 0.05). We conclude that the pipe-line pattern, fed by a large left gastric vein and associated with poorly developed extravariceal portosystemic shunt, is a distinctive portal venographic feature of sclerotherapy resistant varices.

A comparison of Doppler flowmetry with conventional assessment of acute changes in hepatic blood flow

The validity and clinical relevance of Doppler flowmetry in measuring changes in regional blood flow are uncertain. In the present study we compared changes induced ketanserin in regional splanchnic blood flow as measured by Doppler flowmetry with changes in conventionally measured systemic and in hepatic haemodynamic indices estimated pharmacokinetically using indocyanine green. Fourteen patients with alcoholic cirrhosis and portal hypertension were evaluated. On multivariate analyses, significant associations were noted for only three indices: changes in estimated hepatic blood flow were predicted jointly by changes in flow in the main and right portal veins and hepatic artery (R2 = 0.80); changes in intrahepatic shunting (indocyanine green extraction) were predicted by changes in flow in the main and right portal veins (R2 = 0.55); and changes in sinusoidal perfusion (indocyanine green clearance) were significantly predicted by changes in main portal vein flow alone (R2 = 0.76). These data support the validity of Doppler flowmetry in quantifying change in regional blood flow, but highlight the limitations in its clinical application and interpretation. The association of changes in main portal vein flow with changes in sinusoidal perfusion has clinical potential but requires confirmation using other modulating drugs.

Echo-Doppler measurements of portal vein and superior mesenteric artery blood flow in humans: inter- and intra-observer short-term reproducibility

The reproducibility of echo-Doppler measurements of portal vein and superior mesenteric artery blood flow has not been extensively studied. In the present study, two groups of subjects were examined to test inter- and intra-observer reproducibility. Each study population consisted of 15 nonportal hypertensive and 15 portal hypertensive subjects. With a standardized technique, the crosssectional area and velocity of blood flow in the portal vein and superior mesenteric artery were recorded in triplicate by skilled operators. The flow volume of each vessel was calculated by multiplying the cross-sectional area by the velocity of blood flow. The measurements were performed in a blind fashion over a 60 min period. The reproducibility of measurements was assessed by calculation of intraclass correlation coefficients and coefficients of variation. The intra-observer intraclass correlation coefficient was 0.77 for portal vein blood flow and 0.84 for superior mesenteric artery blood flow, suggesting good reproducibility. The intra-observer coefficient of variation was 11 and 9%, respectively. In contrast, the interobserver intraclass correlation coefficient was calculated to be 0.49 for portal blood vein blood flow and 0.57 for superior mesenteric artery blood flow, indicating fair reproducibility. In addition, the interobserver coefficients of variation were calculated to be 20 and 18%, respectively. These data suggest that intra-observer reproducibility in echo-Doppler measurements of portal vein and superior mesenteric artery blood flow is acceptable but inter-observer reproducibility is not. Examination by a single operator, rather than multiple operators, is therefore advisable. Even when measurements are performed by a single investigator an approximate variance of 10% in the measurement in a single subject should be expected.

Response of blood flow to vasopressin in the collateral left gastric vein in patients with portal hypertension

BACKGROUND/AIMS

A problem in pharmacotherapy for bleeding varices in portal hypertension is non-responders. The aim of this study was to elucidate the features of hemodynamic response to vasopressin in the gastroesophageal collateral vein in patients with esophageal varices.

METHODS

Flow velocity in the portal and the collateral left gastric vein was measured with an echo-Doppler flowmeter before and during infusion of vasopressin, 0.2 U/min, in 41 patients with cirrhosis and esophageal varices.

RESULTS

The decrease in flow velocity in the left gastric vein with vasopressin (-29 +/- 25%) was significantly smaller than that in the portal vein (-56 +/- 20%). There was no or only minimal change in flow velocity in the left gastric vein in 39% of the patients, especially in those with large-size varices. In 28 patients examined by portal catheterization, changes in flow velocity in the left gastric vein were correlated with portal pressure, and portal pressure in non-responders was significantly higher than that in responders (non-responders: 363 +/- 49, responders: 312 +/- 41 mmH2O, p < 0.05).

CONCLUSIONS

It was concluded that hepatofugal blood flow in the gastroesophageal collateral is not readily reduced by vasopressin. However, as the study was performed in a stable condition without variceal bleeding, whether these hemodynamic features will apply during acute variceal bleeding in patients who are known to have a poor hemodynamic response to vasopressin remains to be elucidated.

Interobserver and interequipment variability of echo-Doppler examination of the portal vein: effect of a cooperative training program

The aim of this study was to assess the interobserver, interequipment, and time-dependent variabilities of echo-Doppler measurements of portal blood flow velocity (PBV), portal vein diameters (PVDs) and their derived parameters, portal blood flow (PBF), and congestion index (CI) in cirrhotic patients. The influence of a cooperative training program of the operators on the reproductibility of the results was also investigated. The echo-Doppler parameters were independently measured in 15 patients by four skilled operators, using four echo-Doppler machines (Acuson, ATL, Hitachi-Esaote, Toshiba. Eight of the 15 patients were restudied after 15 days by the same operators using only one machine. Significantly different values of PBV, PBF, and CI were obtained. PBV variance was equipment-related (32%) and operator-related in a smaller portion (5%). No systematic effect related to the time of investigation was found. After training to define a precise protocol, new measurements were performed by four operators on 8 different patients. No significant differences were found among the operators for any of the parameters and the 95% confidence limits (CL) and coefficients of variation (CV) of PBV showed a marked decrease (CL from +/- 26.4% to +/- 15.6%). These results indicate that (1) a significant systematic variability exists between Doppler measurements with different equipment; (2) there is no significant time-dependent systematic variability of Doppler measurements; and (3) a cooperative training program reduces the interobserver variability for direct measurements, such as PBV.

Noninvasive measurement of femoral blood flow and portal pressure response to propranolol in patients with cirrhosis

This study investigated the correlation between changes in hepatic and systemic hemodynamics and femoral blood flow (FBF), measured by dual-beam pulsed wave Doppler, in 58 portal hypertensive patients receiving propranolol (0.15 mg/Kg intravenously; n = 44) or placebo (n = 14) under double-blind conditions. Placebo administration had no effects. Propranolol caused significant reductions (P < .0001) in hepatic venous pressure gradient (HVPG; from 19.1 +/- 4.1 to 16.2 +/- 4.2 mm Hg), azygos blood flow (from 563 +/- 204 to 387 +/- 176 mL/min), cardiac index (CI; from 4.4 +/- 1.0 to 3.3 +/- 0.8 L/m2/min), and FBF (from 237 +/- 79 to 176 +/- 58 mL/m2/min). In 17 patients HVPG decreased below 12 mm Hg and/or more than 20% of the baseline value (good response; mean change, -26 +/- 8%); in the remaining 27 patients (poor response) the mean change in HVPG was less: -9 +/- 6%. Patients with a good response had bled less often from varices, had significantly higher FBF (272 +/- 73 vs. 215 +/- 76 mL/m2/min) and lower baseline HVPG (16.8 +/- 3.9 vs. 20.6 +/- 3.6 mm Hg) than those with poor response in HVPG. The good response was also associated with greater decreases in FBF (-33 +/- 12 vs. -19 +/- 13% in poor responders), CI (-30 +/- 9 vs. -19 +/- 12%), and heart rate (-19 +/- 5 vs. -16 +/- 6%). A decrease in FBF of > 20% predicted a good response in 16 of 28 patients (positive predictive value, 57%).(ABSTRACT TRUNCATED AT 250 WORDS)

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 propranolol on gastric mucosal perfusion and serum gastrin level in cirrhotic patients with portal hypertensive gastropathy

Gastric mucosal hyperemia associated with elevated serum gastrin level has been suggested in cirrhotic patients with portal hypertensive gastropathy (PHG). Clinical evidence has shown that these patients may benefit from propranolol administration. The aim of this study was to investigate effect of propranolol on gastric mucosal perfusion and serum gastrin level in cirrhotic patients with portal hypertensive gastropathy. Gastric mucosal perfusion was assessed by laser Doppler flowmetry. Measurements were performed under basal conditions and after observer-blind administration of propranolol (30-60 mg/day, N = 9) or placebo (N = 9) for seven days. Placebo had no effect on either gastric mucosal perfusion or serum gastrin level. In contrast, propranolol administration significantly decreased both antrum gastric mucosal perfusion (from 0.88 +/- 0.28 to 0.73 +/- 0.26 V, P < 0.05) and corpus gastric mucosal perfusion (from 0.94 +/- 0.35 to 0.78 +/- 0.25 V, P < 0.05). However, this drug had no effect on serum gastrin level. We conclude that chronic propranolol administration in cirrhotic patients with portal hypertensive gastropathy may reduce gastric mucosal perfusion without changing serum gastrin level.

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.

Portal venous flow and follow-up in patients with liver disease and healthy subjects. Assessment with duplex Doppler

The evolution of portal venous flow in non-end-stage chronic liver disease with portal hypertension was assessed in 59 patients and compared with that in 55 control subjects and by means of duplex Doppler measurements by a single observer. All patients were prospectively followed up, and a repeated measurement was performed in a subgroup of 23 patients. The mean (+/- SD) portal venous diameter and velocity of patients versus controls were 11.2 (+/- 2.0) mm versus 10.1 (+/- 1.4) mm (p < 0.0005) and 11.0 (+/- 4.2) cm/sec versus 13.9 (+/- 4.1) cm/sec (p < 0.0005). The portal venous flow did not differ: 671 (+/- 291) ml/min versus 652 (+/- 203) ml/min. Diagnosis, Child class, and grade of varices did not influence the portal flow. Patients were followed up during a median (+/- SD) time of 47 (+/- 17) months. Nineteen (32%) patients died, and 14 (23%) had a variceal hemorrhage. Survival and hemorrhage were not correlated with the portal venous flow. Subsequent measurements in 23 patients showed a significant decrease in portal venous flow in 5 patients who died during follow-up. This was not found in the patients who survived. It is concluded that portal venous flow in chronic liver disease with portal hypertension is stable for a long time in the evolution of chronic liver disease. The existence of a 'portostat' is postulated. Only in the terminal stage of liver disease can a reduction of the portal venous flow be detected.

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.

Duplex Doppler measurements of the portal vein in portal hypertension

In order to assess the validity of quantitative duplex Doppler measurements of portal vein flow, 10 patients with proven diffuse liver disease and portal hypertension were examined serially by two independent observers over a 3 month period. Multiple measurements of the portal vein were made using a consistent technique in an attempt to minimize observer errors. One patient proved unsuitable for ultrasound examination. In the remaining nine patients the intra-observer portal vein measurements for one observer (19 paired examinations) correlated significantly for flow velocity (r = 0.80, P < 0.001) and derived bulk flow (r = 0.54, P < 0.02) but not for cross-sectional area (r = 0.27, P > 0.05). The intra-observer measurements for the second observer (11 paired examinations) were significantly correlated for cross-sectional area (r = 0.64, P < 0.05) and derived bulk flow (r = 0.61, P < 0.05) but not for flow velocity (r = 0.5, P > 0.05). The inter-observer measurements (28 paired examinations) of the portal vein were all highly significantly correlated for cross-sectional area (r = 0.63, P < 0.001), flow velocity (r = 0.79, P < 0.001) and derived bulk flow (r = 0.73, P < 0.001). These results suggest that this quantitative Doppler technique may be valid for the serial study of portal vein flow in selected groups of patients with diffuse liver disease and portal hypertension.

Modified Doppler flowmetry in the splanchnic circulation

BACKGROUND

Absolute measurements of blood flow by Doppler ultrasonography are subject to substantial error. A simplified method of Doppler flowmetry using conventional duplex Doppler equipment was studied to establish its validity in determining short-term changes in flow in the splanchnic circulation in portal hypertension.

METHODS

Two simple indices were measured: peak velocity averaged over two cardiac cycles and vessel diameter. The relationship between peak and mean velocity was studied using a Doppler phantom. The feasibility of studying relevant vessels and the constancy of regional flow was determined by performing Doppler flowmetry in a basal state twice within 2 hours.

RESULTS

Constancy of relationship between peak and mean velocities was confirmed (r > 0.98). Examination was successful in the majority of 28 consecutive patients with portal hypertension for superior mesenteric, main portal, right portal, and paraumbilical (when patent) veins, but was successful in only 54% for the hepatic artery. Constancy of basal flow was found in 11 selected patients when group data were considered, but in individuals, substantial and unpredictable variance was found.

CONCLUSIONS

Modified Doppler flowmetry appears valid in the assessment of short-term changes in splanchnic blood flow of patients with portal hypertension. Individual variance in baseline flow is identified as a potential problem and is further reason for caution in the interpretation of measurements of Doppler flow.

Effects of propranolol on gastric mucosal perfusion in cirrhotic patients with portal hypertensive gastropathy

This study investigated the effects of the short-term administration of propranolol on gastric blood perfusion in cirrhotic patients with portal hypertensive gastropathy. Portal hypertensive gastropathy is a common cause of nonvariceal bleeding in cirrhosis, which is associated with increased gastric mucosal perfusion and is favorably influenced by propranolol therapy. Gastric mucosal perfusion was evaluated with laser-Doppler flowmetry and reflectance spectrophotometry. Measurements were performed under basal conditions and after the double-blind administration of propranolol (0.15 mg/kg intravenously) or placebo. Propranolol administration significantly reduced (p < 0.001) the laser-Doppler signal (2.93 +/- 0.23 vs. 2.25 +/- 0.22 V) and the hemoglobin content of the gastric mucosa (99.2 +/- 3.8 vs. 89.3 +/- 3.1 arbitrary units), whereas the oxygen content remained unchanged (37.4 +/- 1.2 vs. 36.9 +/- 1.0 arbitrary units). Placebo administration had no effect in any of these parameters. Changes in gastric perfusion after propranolol administration were associated with a significant decrease in hepatic venous pressure gradient and azygos blood flow. We conclude that short-term propranolol administration, in addition to lowering portal pressure, reduces the increased gastric blood perfusion in cirrhotic patients with portal hypertensive gastropathy, an effect that may contribute to prevention of bleeding from these lesions.

Long term management of oesophageal varices

Effective control of variceal rebleeding (secondary prophylaxis) or prevention of the initial bleeding (primary prophylaxis) are the main objectives of the treatment of portal hypertension. Endoscopic sclerotherapy is the treatment of choice for secondary prophylaxis, since it significantly decreases rebleeding and, to some extent, mortality. A combination of propranolol and sclerotherapy may be of benefit by decreasing postsclerotherapy rebleeding. Endoscopic variceal band ligation and transjugular intrahepatic shunt are emerging as useful alternative techniques. Devascularisation and preferably selective shunts should be reserved for use as salvage of sclerotherapy failures. Liver transplantation, if feasible, could become the ultimate therapy by controlling variceal bleeding and improving hepatic function. Pharmacotherapy, while not very successful for secondary prophylaxis, has shown promise for primary prophylaxis of variceal bleeding. Nonselective beta-blockers significantly decrease the rebleeding rates but are associated with only marginal survival benefits. beta-Blockers alone cannot decrease the hepatic venous pressure gradient adequately (to less than 12mm Hg). Combination with nitrates and other drugs may prove beneficial and requires clinical evaluation. Endoscopic sclerotherapy and surgery have little role in primary prevention of variceal bleeding in patients with cirrhosis but need evaluation in noncirrhotic patients.