Hepatic vein pressure gradient reduction and prevention of variceal bleeding in cirrhosis: a systematic review

Duplex Doppler ultrasound examination of the portal venous system: an emerging novel technique for the estimation of portal vein pressure

PURPOSE

Measurement of portal venous pressure in patients with portal hypertension is important to assess efficacy of beta blockers in patients with esophageal varices. Currently, the gold standard for measurement of portal venous pressure is the estimation of hepatic venous pressure gradient (HVPG). Being an invasive technique, serial measurements of HVPG are not feasible in clinical practice. In this respect, duplex Doppler ultrasound (DDUS) examination is an upcoming non-invasive technique for the estimation of portal venous and splanchnic hemodynamics. The aim of the present review is to analyze the current literature focusing on how the two techniques compare to each other in terms of assessing the portal pressure and assessing pitfalls in the current technique.

RESULTS

Duplex Doppler ultrasound (DDUS) currently has limitations in measuring the portal pressure in a non-invasive way. Hemodynamic venous and arterial indices measured on DDUS correlate with the HVPG. The technique has been refined, however, there is no uniform surrogate marker that can be used in clinical practice.

CONCLUSIONS

More studies are needed in order to remove the shortcomings in the current technique. The target is to be able to measure the actual portal pressure or at least derive an ideal venous or arterial hemodynamic surrogate marker having close correlation with the HVPG.

Microwave coagulation versus sclerotherapy after band ligation to prevent recurrence of high risk of bleeding esophageal varices in Child-Pugh's A and B patients

BACKGROUND

The combination of endoscopic band ligation (EBL) with either endoscopic injection sclerotherapy (EIS) or thermal therapy has been shown to reduce recurrence of esophageal varices compared to EBL alone. The aim of this prospective trial was twofold: 1) to evaluate the safety and efficacy of EBL used in association with microwave coagulation (MC), a thermal endoscopic therapy method, for treating esophageal varices and preventing recurrence; and 2) to compare these results to the joint application of EBL and EIS.

METHODS

Seventy cirrhotic patients with bleeding esophageal varices were treated with EBL until only thin vessels remained. Thirty-six randomly selected patients received EIS (group A) and 34 received MC (group B) until complete eradication had been achieved. Endoscopic follow-up was performed to detect recurrence. The effectiveness of the treatment was measured using variceal recurrence, rebleeding, intervention complications, and recurrence factors.

RESULTS

During follow-up evaluations averaging 34.9 +/- 11.4 months, no significant differences were found between groups A and B in variceal recurrence (27.7 vs. 17.6%, P = 0.31) or rebleeding (8.3 vs. 0%, P = 0.23). Complications were rare, with no difference detected between groups. The presence of gastric varices influenced recurrence with an odds ratio of 3.9 (95% CI 1.14-13.1, P = 0.029).

CONCLUSIONS

Application of MC to esophageal varices after band ligation is safe. The post-MC recurrence rate may be comparable to that observed following the combined treatment of EBL and EIS. The presence of gastric varices increases the risk of esophageal variceal recurrence.

Hepatic venous pressure gradient can predict the development of hepatocellular carcinoma and hyponatremia in decompensated alcoholic cirrhosis

OBJECTIVE

Portal hypertension is closely associated with serious complications of cirrhosis, which contribute to bad prognosis. Hepatocellular carcinoma (HCC) and low serum sodium (SNa) are manifestations of end-stage liver disease and are associated with poor survival in decompensated cirrhosis patients. We aimed to determine the relationship between hepatic venous pressure gradient (HVPG) and the development of HCC or low SNa in decompensated alcoholic cirrhosis patients.

METHODS

Child-Pugh scores, Model for End-Stage Liver Disease scores, and HVPG at baseline, and the development of HCC or low SNa (SNa <130 mEq/l) during follow-up were analyzed prospectively in 170 patients with decompensated alcoholic cirrhosis from December 1999 to January 2008 (mean follow-up period of 33.9+/-27.9 months). The predictive value of different risk factors for the development of HCC and low SNa and survival were investigated.

RESULTS

Twenty-four patients developed HCC during the follow-up period. In the multivariate analysis, only baseline HVPG greater than 15 mmHg was an independent predictive factor for the development of HCC (relative risk=1.128, P<0.05) and which showed a significantly shorter time for the development of HCC on the Kaplan-Meier analysis. Twenty patients developed low SNa during follow-up. Initial HVPG was also an independent predictive factor for the new development of low SNa in the multivariate analysis (relative risk=1.169, P<0.05) and which also showed significantly shorter times for the development of low SNa on the Kaplan-Meier analysis.

CONCLUSION

In decompensated alcoholic cirrhosis, HVPG may be a useful predictive factor for the development of HCC and low SNa.

The clinical use of HVPG measurements in chronic liver disease

Portal hypertension is a severe, almost unavoidable complication of chronic liver diseases and is responsible for the main clinical consequences of cirrhosis. Measurement of the hepatic venous pressure gradient (HVPG) is currently the best available method to evaluate the presence and severity of portal hypertension. Clinically significant portal hypertension is defined as an increase in HVPG to >or=10 mmHg; above this threshold, the complications of portal hypertension might begin to appear. Measurement of HVPG is increasingly used in clinical hepatology, and numerous studies have demonstrated that the parameter is a robust surrogate marker for hard clinical end points. The main clinical applications for HVPG include diagnosis, risk stratification, identification of patients with hepatocellular carcinoma who are candidates for liver resection, monitoring of the efficacy of medical treatment, and assessment of progression of portal hypertension. Patients who experience a reduction in HVPG of >or=20% or to <12 mmHg in response to drug therapy are defined as 'responders'. Responders have a markedly decreased risk of bleeding (or rebleeding), ascites, and spontaneous bacterial peritonitis, which results in improved survival.

Antiviral therapy reduces portal pressure in patients with cirrhosis due to HBeAg-negative chronic hepatitis B and significant portal hypertension

BACKGROUND/AIMS

Lamivudine improves liver histology in patients with chronic hepatitis B (CHB), but its effects on portal pressure remain unknown. We evaluated the effect of lamivudine monotherapy on hepatic venous pressure gradient (HVPG) in CHB-related cirrhosis with significant portal hypertension.

METHODS

We studied 19 patients with cirrhosis due to HBeAg-negative CHB and HVPG >or=10 mm Hg treated with oral lamivudine (100mg daily). Liver biochemistry, Child-Pugh and MELD score were determined every 3 months, alpha-fetoprotein and HBV DNA every 6 months and HVPG at baseline and at 12 months after lamivudine initiation. Diuretics, beta-blockers, antibiotics and/or endoscopic therapy were used for routine indications.

RESULTS

At 12 months, a significant reduction was observed in ALT (p=0.001), HBV DNA (p=0.002), Child-Pugh (p=0.012) and MELD score (p=0.006). Four patients developed virological breakthrough during treatment. At 12 months, HVPG decreased in all but one patient [baseline: 14.4+/-3.9 and 12 months: 12.4+/-3.3 mm Hg (p=0.007)]. HVPG decreased >20% or below the 12 mm Hg threshold in 10 of 13 patients with baseline HVPG >or=12 mm Hg. HVPG increased in a patient with hepatic flare after virological breakthrough.

CONCLUSION

In conclusion, in patients with cirrhosis due to HBeAg-negative CHB, lamivudine monotherapy reduces HVPG, especially when virological suppression and biochemical remission is achieved.

Randomized controlled trial of carvedilol versus variceal band ligation for the prevention of the first variceal bleed

Current therapy for preventing the first variceal bleed includes beta-blocker and variceal band ligation (VBL). VBL has lower bleeding rates, with no differences in survival, whereas beta-blocker therapy can be limited by side effects. Carvedilol, a non-cardioselective vasodilating beta-blocker, is more effective in reducing portal pressure than propranolol; however, there have been no clinical studies assessing the efficacy of carvedilol in primary prophylaxis. The goal of this study was to compare carvedilol and VBL for the prevention of the first variceal bleed in a randomized controlled multicenter trial. One hundred fifty-two cirrhotic patients from five different centers with grade II or larger esophageal varices were randomized to either carvedilol 12.5 mg once daily or VBL performed every 2 weeks until eradication using a multibander device. Seventy-seven patients were randomized to carvedilol and 75 to VBL. Baseline characteristics did not differ between the groups (alcoholic liver disease, 73%; median Child-Pugh score, 8; median age, 54 years; median follow-up, 20 months). On intention-to-treat analysis, carvedilol had lower rates of the first variceal bleed (10% versus 23%; relative hazard 0.41; 95% confidence interval 0.19-0.96 [P = 0.04]), with no significant differences in overall mortality (35% versus 37%, P = 0.71), and bleeding-related mortality (3% versus 1%, P = 0.26). Six patients in the VBL group bled as a result of banding ulcers. Per-protocol analysis revealed no significant differences in the outcomes.

CONCLUSION

Carvedilol is effective in preventing the first variceal bleed. Carvedilol is an option for primary prophylaxis in patients with high-risk esophageal varices.

[Comparison of the Model for End-stage Liver Disease and hepatic venous pressure gradient for predicting survival in patients with decompensated liver cirrhosis]

BACKGROUND/AIMS

This study compared the prognostic values of the Model for End-stage Liver Disease (MELD) and the hepatic venous pressure gradient (HVPG) in the prediction of death within 3 and 12 months in patients with decompensated liver cirrhosis.

METHODS

We used data from 136 consecutive patients with decompensated cirrhosis who underwent HVPG between January 2006 and June 2008. Cox regression analysis was used to investigate the independent relationships with death of MELD and HVPG. The prognostic accuracies of MELD and HVPG were analyzed by calculating the area under the receiver operating characteristic curve (AUROC) for the occurrence of death within 3 and 12 months.

RESULTS

Both MELD and HVPG were independent predictors of death [hazard ratio (HR)=1.11 and 1.12, respectively; 95% confidence interval (CI)=1.04~1.20 and 1.08-1.16]. Analysis of the AUROC demonstrated that the prognostic power did not differ between MELD and HVPG for predicting the 3-month survival (HR=0.76 and 0.68, respectively; 95% CI=0.62~0.89 and 0.52~0.84; P=0.22) or the 12-month survival (HR=0.72 and 0.73, 95% CI=0.61~0.83 and CI=0.61~0.84).

CONCLUSIONS

Both MELD and HVPG are independent prognostic factors of death within 3 and 12 months in patients with decompensated liver cirrhosis, and their accuracies are similar. However, HVPG has a limited role in the prediction of death in decompensated cirrhosis due to its invasiveness and limited use.

Prognostic value of acute hemodynamic response to i.v. propranolol in patients with cirrhosis and portal hypertension

BACKGROUND/AIMS

Cirrhotic patients chronically treated with beta-blockers who achieve a decrease of hepatic venous pressure gradient (HVPG) > or =20% from baseline or to < or =12 mmHg have a marked reduction of first bleeding or re-bleeding. However, two HVPG measurements are needed to evaluate response. This study was aimed at investigating the predictive role of acute HVPG response to i.v. propranolol for bleeding and survival.

METHODS

We retrospectively studied 166 cirrhotic patients with varices with HVPG response to i.v. propranolol (0.15 mg/kg). All patients subsequently received non-selective beta-blockers to prevent first bleeding (n=78) or re-bleeding (n=88).

RESULTS

Thirty-seven patients developed a portal hypertension-related bleeding over 2 years of follow-up. Decrease (12%) in HVPG was the best cut-off for bleeding risk discrimination. This parameter was used to classify patients in responders (n=95) and non-responders (n=71). In primary prophylaxis (54 responders vs. 24 non-responders) the actuarial probability of bleeding was half in responders than in non-responders (12% vs. 23% at 2 years; ns). In secondary prophylaxis (41 responders vs. 47 non-responders) a good hemodynamic response was also significantly and independently associated with a 50% decrease in the probability of re-bleeding (23% at 2 years vs. 46% in non-responders; p=0.032) and a better survival (95% vs. 65%; p=0.003).

CONCLUSION

The evaluation of acute HVPG response to i.v. propranolol before initiating secondary prophylaxis for variceal bleeding is a useful tool in predicting the efficacy of non-selective beta-blockers. If adequately validated, this might be a more cost-effective strategy than the chronic evaluation of HVPG response and might be useful to guide therapeutic decisions in these patients.

[Progress in portal hypertension]

In patients with portal hypertension due to cirrhosis, the mechanisms responsible for circulatory modifications are well-known. An elevation in intrahepatic vascular resistance related to a hepatic endothelin hyperproduction and an arterial nitric oxide (NO) hyperproduction. The presence and the degree of portal hypertension might be determined by the measurement of the hepatic venous pressure gradient but non-invasive technique as FibroTest or FibroScan might be useful to estimate the presence of severe portal hypertension. Numerous substances decrease portal pressure either by reducing hepatic vascular resistance or by reducing portal tributary blood flow. The combination of both types of substances is probably the best pharmacological treatment of portal hypertension but further hemodynamic and clinical studies are needed.

Acute hemodynamic response to beta-blockers and prediction of long-term outcome in primary prophylaxis of variceal bleeding

BACKGROUND & AIMS

Studies of variceal bleeding have shown that a hemodynamic response to treatment of portal hypertension is appropriate when the hepatic venous pressure gradient (HVPG) decreases below 12 mmHg or by > 20% from baseline. However, in primary prophylaxis, many nonresponders do not bleed and 2 invasive procedures are needed to assess response. We investigated the long-term prognostic value of an acute response to beta-blockers and whether the target reduction in HVPG can be improved in primary prophylaxis.

METHODS

An initial hemodynamic study was performed in patients with large varices and without previous bleeding. After baseline measurements were made, propranolol was administered intravenously and measurements were repeated 20 minutes later. Patients were given nadolol daily and a second hemodynamic study was performed.

RESULTS

Of 105 patients, 15% had variceal bleeding. Using receiver operating characteristic curve analysis, a decrease of HVPG > or = 10% was the best value to predict bleeding. In the initial study, 75 patients (71%) were responders (HVPG decreased to < or = 12 mmHg or by > or = 10%) and had a lower probability of first bleeding than nonresponders (4% vs 46% at 24 months; P < .001). Acute responders also had a lower risk of developing ascites (P = .001). Chronic responders had a lower probability of bleeding than nonresponders (P < .001). There was a correlation between acute and chronic changes in HVPG (r = 0.62; P = .01).

CONCLUSION

The acute hemodynamic response to beta-blockers can be used to predict the long-term risk of first bleeding. An HVPG reduction > 10% from baseline is the best target to define response in primary prophylaxis.

Management and treatment of patients with cirrhosis and portal hypertension: recommendations from the Department of Veterans Affairs Hepatitis C Resource Center Program and the National Hepatitis C Program

Cirrhosis represents the end stage of any chronic liver disease. Hepatitis C and alcohol are currently the main causes of cirrhosis in the United States. Although initially cirrhosis is compensated, it eventually becomes decompensated, as defined by the presence of ascites, variceal hemorrhage, encephalopathy, and/or jaundice. These management recommendations are divided according to the status, compensated or decompensated, of the cirrhotic patient, with a separate section for the screening, diagnosis, and management of hepatocellular carcinoma (HCC), as this applies to patients with both compensated and decompensated cirrhosis. In the compensated patient, the main objective is to prevent variceal hemorrhage and any practice that could lead to decompensation. In the decompensated patient, acute variceal hemorrhage and spontaneous bacterial peritonitis are severe complications that require hospitalization. Hepatorenal syndrome is also a severe complication of cirrhosis but one that usually occurs in patients who are already in the hospital and, as it represents an extreme of the hemodynamic alterations that lead to ascites formation, it is placed under treatment of ascites. Recent advances in the pathophysiology of the complications of cirrhosis have allowed for a more rational management of cirrhosis and also for the stratification of patients into different risk groups that require different management. These recommendations are based on evidence in the literature, mainly from randomized clinical trials and meta-analyses of these trials. When few or no data exist from well-designed prospective trials, emphasis is given to results from large series and consensus conferences with involvement of recognized experts. A rational management of cirrhosis will result in improvements in quality of life, treatment adherence, and, ultimately, in outcomes.

Hepatic venous pressure gradient: worth another look?

Portal hypertension is one of the most important complications of chronic liver disease and accounts for significant morbidity and mortality. Measurement of the hepatic venous pressure gradient (HVPG) is a simple, invasive, and reproducible method of assessing portal venous pressure. Measurement of HVPG provides the clinician an estimate of the degree of intrahepatic portal flow resistance, guides therapy for variceal bleeding (primary and secondary prophylaxis), assesses feasibility of resection in patients with hepatocellular cancer, and predicts response to therapy of patients with chronic hepatitis C. Achieving hemodynamic targets of reducing the HVPG to <10 mmHg or a 20% reduction from baseline virtually eliminates complications related to portal hypertension from chronic liver disease. This review explores the role of HVPG measurement in the contemporary treatment of patients with cirrhosis and portal hypertension.

Pathophysiologic basis for the medical management of portal hypertension

BACKGROUND

Portal hypertension is a potentially life-threatening complication of cirrhosis, resulting from increased intrahepatic resistance and portal inflow.

OBJECTIVE

Given the complex nature of this disorder, a more complete understanding of the pathophysiology of portal hypertension is necessary to develop new therapies that target specific pathways that regulate portal pressure.

METHODS

This review is based on a literature search of published articles and abstracts on the pathophysiology of portal hypertension, its complications and its treatment.

RESULTS/CONCLUSION

A number of therapies have been developed or are under investigation for the treatment of portal hypertension and its complications. These agents may reduce mortality and improve quality of life for patients with advanced liver disease.

Simvastatin lowers portal pressure in patients with cirrhosis and portal hypertension: a randomized controlled trial

BACKGROUND & AIMS

Simvastatin improves liver generation of nitric oxide and hepatic endothelial dysfunction in patients with cirrhosis, so it could be an effective therapy for portal hypertension. This randomized controlled trial evaluated the effects of continuous simvastatin administration on the hepatic venous pressure gradient (HVPG) and its safety in patients with cirrhosis and portal hypertension.

METHODS

Fifty-nine patients with cirrhosis and portal hypertension (HVPG > or =12 mm Hg) were randomized to groups that were given simvastatin 20 mg/day for 1 month (increased to 40 mg/day at day 15) or placebo in a double-blind clinical trial. Randomization was stratified according to whether the patient was being treated with beta-adrenergic blockers. We studied splanchnic and systemic hemodynamics and variables of liver function and safety before and after 1 month of treatment.

RESULTS

Simvastatin significantly decreased HVPG (-8.3%) without deleterious effects in systemic hemodynamics. HVPG decreases were observed in patients who were receiving beta-adrenergic blockers (-11.0%; P = .033) and in those who were not (-5.9%; P = .013). Simvastatin improved hepatic, fractional, and intrinsic clearance of indocyanine green, showing an improvement in effective liver perfusion and function. No significant changes in HVPG and liver function were observed in patients receiving placebo. The number of patients with adverse events did not differ significantly between groups. No patient was withdrawn from the study based on adverse events.

CONCLUSIONS

Simvastatin decreased HVPG and improved liver perfusion in patients with cirrhosis. These effects were additive with those of beta-adrenergic blockers. The beneficial effects of simvastatin should be confirmed in long-term clinical trials for portal hypertension.

Beneficial effects of sorafenib on splanchnic, intrahepatic, and portocollateral circulations in portal hypertensive and cirrhotic rats

Portal hypertension, the most important complication in patients with cirrhosis of the liver, is a serious and life-threatening disease for which there are few therapeutic options. Because angiogenesis is a pathological hallmark of portal hypertension, the goal of this study was to determine the effects of sorafenib-a potent inhibitor of proangiogenic vascular endothelial growth factor receptor 2 (VEGFR-2), platelet-derived growth factor receptor beta (PDGFR-beta), and Raf kinases-on splanchnic, intrahepatic, systemic, and portosystemic collateral circulations in two different experimental models of portal hypertension: rats with prehepatic portal hypertension induced by partial portal vein ligation and rats with intrahepatic portal hypertension and secondary biliary cirrhosis induced by bile duct ligation. Such a comprehensive approach is necessary for any translational research directed toward defining the efficacy and potential clinical application of new therapeutic agents. Sorafenib administered orally once a day for 2 weeks in experimental models of portal hypertension and cirrhosis effectively inhibited VEGF, PDGF, and Raf signaling pathways, and produced several protective effects by inducing an approximately 80% decrease in splanchnic neovascularization and a marked attenuation of hyperdynamic splanchnic and systemic circulations, as well as a significant 18% decrease in the extent of portosystemic collaterals. In cirrhotic rats, sorafenib treatment also resulted in a 25% reduction in portal pressure, as well as a remarkable improvement in liver damage and intrahepatic fibrosis, inflammation, and angiogenesis. Notably, beneficial effects of sorafenib against tissue damage and inflammation were also observed in splanchnic organs.

CONCLUSION

Taking into account the limitations of translating animal study results into humans, we believe that our findings will stimulate consideration of sorafenib as an effective therapeutic agent in patients suffering from advanced portal hypertension.

Clinical trial: a randomized controlled study on prevention of variceal rebleeding comparing nadolol + ligation vs. hepatic venous pressure gradient-guided pharmacological therapy

BACKGROUND

Hepatic venous pressure gradient (HVPG) monitoring of therapy to prevent variceal rebleeding provides strong prognostic information. Treatment of nonresponders to beta-blockers +/- nitrates has not been clarified.

AIM

To assess the value of HVPG-guided therapy using nadolol + prazosin in nonresponders to nadolol + isosorbide-5-mononitrate (ISMN) compared with a control group treated with nadolol + ligation.

METHODS

Cirrhotic patients with variceal bleeding were randomized to HVPG-guided therapy (n = 30) or nadolol + ligation (n = 29). A Baseline haemodynamic study was performed and repeated within 1 month. In the guided-therapy group, nonresponders to nadolol + ISMN received nadolol and carefully titrated prazosin and had a third haemodynamic study.

RESULTS

Nadolol + prazosin decreased HVPG in nonresponders to nadolol + ISMN (P < 0.001). Finally, 74% of patients were responders in the guided-therapy group vs. 32% in the nadolol + ligation group (P < 0.01). The probability of rebleeding was lower in responders than in nonresponders in the guided therapy group (P < 0.01), but not in the nadolol + ligation group (P = 0.41). In all, 57% of nonresponders rebled in the guided-therapy group and 20% in the nadolol + ligation group (P = 0.05). The incidence of complications was similar.

CONCLUSIONS

In patients treated to prevent variceal rebleeding, the association of nadolol and prazosin effectively rescued nonresponders to nadolol and ISMN, improving the haemodynamic response observed in controls receiving nadolol and endoscopic variceal ligation. Our results also suggest that ligation may rescue nonresponders.

Blood products, volume control, and renal support in the coagulopathy of liver disease

Plasma-based products are commonly used in patients who have chronic liver disease to treat perceived coagulopathy despite unproven efficacy and potentially severe risks, such as transfusion-related acute lung injury, which carries a high mortality rate. Moreover, volume expansion may acutely worsen portal hypertension and increase bleeding from the collateral portal vascular bed. Although factor replacement therapy may be warranted in selected situations, its use should be restricted because of the limitations of target tests, such as international normalized ratio, which poorly reflects presence of bleeding diatheses in patients who have cirrhosis. Renal replacement therapies are frequent adjuncts in patients who have cirrhosis and are acutely decompensated, and may correct uremia-related bleeding diathesis and assist in controlling vascular volume, although they are generally limited to use as a bridge to liver transplantation. Novel extracorporeal therapies are emerging and may also have significant interaction with the hemostatic system. Volume contraction and blood conservation therapies are relatively new and promising approaches to reduce use of blood products in liver transplantation.

[Measurement of hepatic venous pressure gradient in liver cirrhosis: relationship with the status of cirrhosis, varices, and ascites in Korea]

BACKGROUND/AIMS

The relationships between the hepatic venous pressure gradient (HVPG) and the status of cirrhosis, complications of portal hypertension and the severity of cirrhosis are not clear. The aim of this study was to determine the relationships between HVPG and the complications or status of cirrhosis.

METHODS

The HVPG, gastroesophageal varices, Child-Pugh score, Model for End-Stage Liver Disease (MELD) score, presence of ascites, recent bleeding history and the status of cirrhosis were assessed in a cohort of 172 patients (156 males, 16 females) with liver cirrhosis.

RESULTS

The HVPG was 15.6+/-5.1 (mean+/-SD) mmHg (4-33 mmHg) and was significantly higher in patients in the decompensated stage than in those in the compensated stage (16.6+/-4.3 vs. 10.8+/-6.1 mmHg, respectively; P<0.01). HVPG was higher in bleeders than in nonbleeders (16.9+/-4.5 vs. 12.8+/-5.3 mmHg, respectively; P<0.01), and in patients with ascites than in those without ascites (16.4+/-4.1 vs. 14.5+/-6.2 mmHg, respectively; P<0.05). HVPG was significantly lower in the presence of gastric varices than in their absence (14.0+/-3.4 vs. 16.0+/-5.3 mmHg, respectively; P<0.05); however, no significant correlation was detected between HVPG and the grade of esophageal varices (P>0.05). HVPG was significantly higher in Child's B cirrhosis (n=87, 15.6+/-4.7 mmHg) and Child's C cirrhosis (n=36, 18.4+/-4.7 mmHg) than in Child's A cirrhosis (n=49, 13.7+/-5.1 mmHg; P<0.01). HVPG also was strongly correlated with the MELD score (P<0.01). The time required to measure the HVPG was 11.2+/-6.4 min, and only three cases of minor complication occurred during the procedure.

CONCLUSIONS

HVPG was correlated with the severity of liver cirrhosis, presence of ascites, and risk of variceal bleeding in patients with liver cirrhosis.

Review article: the therapeutic and prognostic benefit of portal pressure reduction in cirrhosis

BACKGROUND

Hepatic venous pressure gradient (HVPG) measurement is not a routinely used technique, despite its therapeutic and prognostic value.

AIM

To review the role of HVPG from published literature.

METHODS

Systematic literature review.

RESULTS

In acute variceal bleeding, HVPG is prognostic identifying 'difficult to treat' group, which now has defined clinical correlations. In secondary prevention of portal hypertensive bleeding, a reduction to < or = 12 mmHg confers near complete protection against rebleeding. The target of > or = 20% HVPG reduction from baseline needs prospective assessment to test a change of therapy, if no reduction occurs. The acute HVPG response to beta-blockade needs further assessment. In primary prevention, the cost-effectiveness of HVPG measurement is not favourable given the efficacy of medical therapy. In chronic liver disease, wedge hepatic venous pressure (WHVP) is prognostic for survival. Pharmacological reduction in portal pressure decreases complications and improves survival, possibly independent of a concomitant improvement in liver function. This latter requires urgent confirmation as it is clinically very relevant. HVPG monitoring can be used to assess anti-viral therapy particularly in cirrhosis, ergonomically combined with transjugular biopsy.

CONCLUSIONS

The prognostic and therapeutic value of HVPG is established beyond portal hypertensive bleeding for which there are some clinical surrogates. HVPG measurement should now be part of everyday clinical practice.

Three-day tetrahydrobiopterin therapy increases in vivo hepatic NOS activity and reduces portal pressure in CCl4 cirrhotic rats

BACKGROUND/AIMS

Tetrahydrobiopterin is an essential cofactor for NOS enzymes to synthesize NO. It has been suggested that reduced intrahepatic tetrahydrobiopterin decreases intrahepatic NO and contributes to increase hepatic vascular resistance and portal pressure in cirrhosis. The main aim of the study was to evaluate the effect of tetrahydrobiopterin supplementation in portal pressure in CCl4 cirrhotic rats.

METHODS

Cirrhotic rats received vehicle or tetrahydrobiopterin (10mg/kg/day i.p.) for 3 days. Hepatic and systemic hemodynamics and hepatic tetrahydrobiopterin, NOS activity and cGMP levels were measured. In addition, hepatic and systemic hemodynamics were evaluated in normal rats in which tetrahydrobiopterin deficiency was induced by administrating 2,4-diamino-6-hydroxy-pyrimidine (DAHP) for 8h.

RESULTS

In cirrhotic rats, tetrahydrobiopterin administration increased liver NOS activity and cGMP levels and markedly and significantly reduced portal pressure. Amelioration of portal hypertension was associated with a normalization of arterial pressure. In normal rats DAHP decreased hepatic tetrahydrobiopterin and NOS activity and increased hepatic vascular tone. These effects of DAHP administration were corrected by tetrahydrobiopterin supplementation.

CONCLUSIONS

The present study shows that tetrahydrobiopterin markedly reduces portal hypertension and improves systemic hemodynamics in cirrhotic rats. These data support the concept that tetrahydrobiopterin supplementation may represent a new therapeutic strategy for portal hypertension.

Avoiding pitfalls: what an endoscopist should know in liver transplantation--part 1

Cirrhosis is associated with global homodynamic changes, but the majority of the complications are usually manifested through the gastrointestinal tract. Therefore, Gastrointestinal Endoscopy has become an important tool in the multidisciplinary approach in the management of these patients. With the ever growing number of cirrhotic patients requiring pre-transplant endoscopic management, it is imperative that the community endoscopists are well aware of the pathologies that can be potentially noted on Gastrointestinal Endoscopy. Their timely management is also considered to have the utmost importance in being able to stabilize the patient until their transfer to a Liver Transplant Center. The aim of this manuscript is to give a comprehensive update and review of various endoscopic findings that a non-transplant endoscopist will encounter in the pre-transplant setting.

The management of portal hypertension: rational basis, available treatments and future options

Variceal bleeding is the last step in a chain of events initiated by an increase in portal pressure, followed by the development and progressive dilation of varices until these finally rupture and bleed. This sequence of events might be prevented - and reversed - by achieving a sufficient decrease in portal pressure. A different approach is the use of local endoscopic treatments at the varices. This article reviews the rationale for the management of patients with cirrhosis and portal hypertension, the current recommendations for the prevention and treatment of variceal bleeding, and outlines the unsolved issues and the perspectives for the future opened by new research developments.

Primary prophylaxis of esophageal variceal bleeding in cirrhosis

Variceal bleeding is a common and severe complication of liver cirrhosis. The risk of bleeding increases with the size of varices, red wheal marks and disease severity. Noninvasive tests are not accurate enough for the diagnosis of varices, so all patients with cirrhosis should be screened by endoscopy. Nonselective beta-blockers (propranolol, nadolol) are indicated for primary prophylaxis in patients with medium/large varices, and for those with small varices and red signs or advanced liver failure (Child C). In such patients, beta-blockers have been shown to reduce the risk of bleeding from 25 to 15%. There is no evidence to support using beta-blockers with nitrates or spironolactone. In patients with contraindication or intolerance to beta-blockers, endoscopic band ligations are indicated.

Prevention of recurrent variceal bleeding

Patients surviving a first episode of variceal bleeding have a risk of over 60% of experiencing recurrent haemorrhages within 1 year from the index episode. Because of this, all patients surviving a variceal bleeding should receive active treatments for the prevention of rebleeding. beta-Blockers+/-isosorbide-5-mononitrate and band ligation are effective in preventing recurrent bleeding and both can be used. Combination of beta-blockers+/-isosorbide-5-mononitrate and band ligation may be the best treatment to prevent rebleeding but more studies are needed to confirm this issue. In patients with recurrent variceal bleeding despite appropriate medical and endoscopic treatment, transjugular intrahepatic porto-systemic shunt is highly effective in controlling bleeding. The efficacy is not significantly different from that of shunt surgery (distal splenorenal shunt or 8mm H-graft shunt), especially since the introduction of polytetrafluoroethylene-covered stents. Therefore, in this situation, transjugular intrahepatic porto-systemic shunt using polytetrafluoroethylene stents should be the treatment of choice.

Current endoscopic therapy of variceal bleeding

Variceal ligation has proved more effective and safer than sclerotherapy and is currently the endoscopic treatment of choice for oesophageal varices. In acute bleeding, vasoactive drugs should be started before endoscopy and maintained for 2-5 days. The efficacy of drugs is improved when associated with emergency endoscopic therapy. Antibiotic prophylaxis should also be used. To prevent rebleeding, both endoscopic ligation and the combination of beta-blockers and nitrates may be used. Adding beta-blockers improves the efficacy of ligation. Haemodynamic responders to beta-blockers+/-nitrates (those with a decrease in portal pressure gradient HVPG to <12 mmHg or by >20% of baseline) have a marked reduction in the risk of haemorrhage and will not need further treatment. Beta-blockers significantly reduce the risk of a first haemorrhage in patients with large varices, and they improve survival. As compared to beta-blockers, endoscopic ligation reduces the risk of first bleeding without affecting mortality, and should be used in patients with contraindications or intolerance to beta-blockers.

Magnetic resonance imaging of hepatic fibrosis: emerging clinical applications

Chronic liver disease and cirrhosis remains a major public health problem worldwide. While the majority of complications from chronic liver disease result from progressive hepatic fibrosis, the available diagnostic tests used in clinical practice are not sensitive or specific enough to detect occult liver injury at early or intermediate stages. While liver biopsy can stage the extent of fibrosis at diagnosis, its utility as a tool for longitudinal monitoring will be limited at the population level. To date, a number of methods including serum marker panels and ultrasound-based transient elastrography have been proposed for the non-invasive identification of hepatic fibrosis. Novel techniques including magnetic resonance (MR) spectroscopy, diffusion weighted MR, and MR elastography have also emerged for detecting fibrosis. In contrast to other non-invasive methods, MR imaging holds the promise of providing functional and biological information about hepatic pathophysiology as it relates to the natural history and future treatment of hepatic fibrosis. (HEPATOLOGY 2007.).

Hepatic venous pressure gradient and outcomes in cirrhosis

End-stage liver disease is characterized by the development of complications related to portal hypertension. Hepatic venous pressure gradient (HVPG), as an estimation of portal pressure, has been associated to the development of these complications. Most of the data that has been published in this regard is in the context of the development of varices and variceal bleeding. However, HVPG has also been associated to the development or the outcome of other complications of portal hypertension, hepatocellular carcinoma, liver transplantation, and survival. This review analyses the published data regarding the association between the HVPG and the different possible outcomes in cirrhosis.

Vascular deterioration in cirrhosis: the big picture

Cirrhosis is characterized by marked abnormalities in the hepatic circulation. Functionally, there is an increased vascular tone and impaired flow-mediated vasorelaxation, whereas anatomically there is sinusoidal remodeling and capillarization, angiogenesis, venous thrombosis, and vascular distortion, all contributing to increase hepatic vascular resistance and portal hypertension. However, vascular changes are not limited to the liver, but are also present in the splanchnic organs, heart, lungs, kidney, brain, and skin. Advances in the knowledge of the mechanisms of these abnormalities have disclosed new targets for therapy and ultimately improved survival.

Preventing first variceal hemorrhage in cirrhosis

Variceal bleeding is still a life-threatening complication of portal hypertension responsible for an appreciable rate of morbidity and mortality. The most appropriate treatment approach, whether drugs (nonselective beta-blockers) or endoscopic (variceal band ligation) therapy, to prevent the initial bleed, or primary prophylaxis, is an issue of controversy. Meta-analysis of randomized controlled trials indicates that banding seems to be somehow slightly more effective than beta-blockers at preventing a first bleeding episode, but this does not translate to improved survival. The firmness of this conclusion is, in addition, diminished by the small sample size and short follow-up of most studies. Moreover, adverse events due to banding are more severe than those associated with beta-blockers. Thus, beta-blockers remain as first-line therapy in patients with cirrhosis and large esophageal varices. Prophylactic therapy with beta-blockers can be considered in patients with small varices, especially in those with red signs or Child class C liver disease. The available evidence does not support the idea that organic nitrates improve the efficacy of beta-blockers in primary prophylaxis. The method used to establish the dose of beta-blockers and check its effect on hepatic venous pressure gradient (HVPG) has also been disputed. An attractive strategy is to measure the HVPG response to beta-blockers as a guide to primary prophylaxis, with the aim of switching to another therapy, that is, band ligation, in HVPG nonresponders. However, no study has yet demonstrated that banding as rescue therapy in nonresponders lowers the risk of first bleeding and improves survival.

Octreotide enhances portal pressure reduction induced by propranolol in cirrhosis: a randomized, controlled trial

BACKGROUND

In vitro, octreotide potentiates vasoconstriction in isolated, preconstricted, mesenteric arterial vessels. In cirrhotic patients, portal pressure (HVPG) reduction induced by propranolol is partly due to splanchnic vasoconstriction.

AIM

To evaluate HVPG effects of octreotide administration in cirrhotic patients receiving long-term propranolol.

PATIENTS AND METHODS

A randomized, controlled trial. First study: a total of 28 patients were studied at baseline and 30 and 60 minutes after octreotide (200 mug) (N = 14) or placebo (N = 14) and then treated with propranolol for approximately 30 days (106 +/- 5 mg/day). Second study: after baseline evaluation patients received octreotide or placebo as they were assigned to in the first study and measurements repeated 30 and 60 minutes later.

RESULTS

In the first study baseline HVPG was 18.7 +/- 0.9 mmHg and decreased to 17.1 +/- 1.1 mmHg and 17.1 +/- 1.0 mmHg (both P < 0.05 vs baseline) at 30 and 60 minutes after octreotide, respectively. Eight patients decreased their HVPG after octreotide. In the second study baseline HVPG was 15.6 +/- 1.3 mmHg (P < 0.01 vs baseline HVPG in first study) and decreased to 14.1 +/- 1.2 mmHg and 14.1 +/- 1.3 mmHg (25.7 +/- 5% lower than baseline HVPG in the first study, P < 0.01) (both P < 0.05 vs baseline) at 30 and 60 minutes after octreotide, respectively. Nine patients (2 responders/7 nonresponders to propranolol) decreased their HVPG after octreotide. Octreotide effects may be mediated by potentiation and additive mechanisms.

CONCLUSIONS

Octreotide enhances HVPG reduction induced by propranolol in cirrhotic patients.

Reversal of portal hypertension and hyperdynamic splanchnic circulation by combined vascular endothelial growth factor and platelet-derived growth factor blockade in rats

Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) pathways are crucial to angiogenesis, a process that contributes significantly to the pathogenesis of portal hypertension. This study determined the effects of inhibition of VEGF and/or PDGF signaling on hyperdynamic splanchnic circulation and portosystemic collateralization in rats with completely established portal hypertension, thus mimicking the situation in patients. Portal vein-ligated rats were treated with rapamycin (VEGF signaling inhibitor), Gleevec (PDGF signaling inhibitor), or both simultaneously when portal hypertension was already fully developed. Hemodynamic studies were performed by transit-time flowmetry. The extent of portosystemic collaterals was measured by radioactive microspheres. The expression of angiogenesis mediators was determined by Western blotting and immunohistochemistry. Combined inhibition of VEGF and PDGF signaling significantly reduced splanchnic neovascularization (i.e., CD31 and VEGFR-2 expression) and pericyte coverage of neovessels (that is, alpha-smooth muscle actin and PDGFR-beta expression) and translated into hemodynamic effects as marked as a 40% decrease in portal pressure, a 30% decrease in superior mesenteric artery blood flow, and a 63% increase in superior mesenteric artery resistance, yielding a significant reversal of the hemodynamic changes provoked by portal hypertension in rats. Portosystemic collateralization was reduced as well.

CONCLUSIONS

Our results provide new insights into how angiogenesis regulates portal hypertension by demonstrating that the maintenance of increased portal pressure, hyperkinetic circulation, splanchnic neovascularization, and portosystemic collateralization is regulated by VEGF and PDGF in portal hypertensive rats. Importantly, these findings also suggest that an extended antiangiogenic strategy (that is, targeting VEGF/endothelium and PDGF/pericytes) may be a novel approach to the treatment of portal hypertension.

Hepatic venous pressure gradient predicts clinical decompensation in patients with compensated cirrhosis

BACKGROUND AND AIMS

Our aim was to identify predictors of clinical decompensation (defined as the development of ascites, variceal hemorrhage [VH], or hepatic encephalopathy [HE]) in patients with compensated cirrhosis and with portal hypertension as determined by the hepatic venous pressure gradient (HVPG).

METHODS

We analyzed 213 patients with compensated cirrhosis and portal hypertension but without varices included in a trial evaluating the use of beta-blockers in preventing varices. All had baseline laboratory tests and HVPG. Patients were followed prospectively every 3 months until development of varices or VH or end of study. To have complete information, until study termination, about clinical decompensation, medical record review was done. Patients who underwent liver transplantation without decompensation were censored at transplantation. Cox regression models were developed to identify predictors of clinical decompensation. Receiver operating characteristic (ROC) curves were constructed to evaluate diagnostic capacity of HVPG.

RESULTS

Median follow-up time of 51.1 months. Sixty-two (29%) of 213 patients developed decompensation: 46 (21.6%) ascites, 6 (3%) VH, 17 (8%) HE. Ten patients received a transplant and 12 died without clinical decompensation. Median HVPG at baseline was 11 mm Hg (range, 6-25 mm Hg). On multivariate analysis, 3 predictors of decompensation were identified: HVPG (hazard ratio [HR], 1.11; 95% confidence interval [CI], 1.05-1.17), model of end-stage liver disease (MELD) (HR, 1.15; 95% CI, 1.03-1.29), and albumin (HR, 0.37; 95% CI, 0.22-0.62). Diagnostic capacity of HVPG was greater than for MELD or Child-Pugh score.

CONCLUSIONS

HVPG, MELD, and albumin independently predict clinical decompensation in patients with compensated cirrhosis. Patients with an HVPG <10 mm Hg have a 90% probability of not developing clinical decompensation in a median follow-up of 4 years.

A 3-month course of long-acting repeatable octreotide (sandostatin LAR) improves portal hypertension in patients with cirrhosis: a randomized controlled study

OBJECTIVE

In patients with cirrhosis, acute octreotide administration may transiently decrease the hepatic venous pressure gradient (HVPG). Information on long-term effects of octreotide is limited and controversial. We evaluated portal and systemic hemodynamics following a prolonged administration of long-acting octreotide in patients with cirrhosis.

METHODS

Eighteen cirrhotic patients (alcoholic 12; age 55 yr [44-69]; Pugh's score 7.8; HVPG 17.3 mmHg [12-22]), no steatohepatitis on histology, were randomized to intramuscular octreotide 20 mg (group A) q 4 wk for 3 months or placebo (group B) in a double-blind fashion. At baseline and 3 months, we measured the HVPG, systemic hemodynamics, endothelin-1 (ET-1), and vascular endothelial growth factor (VEGF) in hepatic venous blood.

RESULTS

Patients remained compensated except for one episode of infection in each group. At 3 months, the HVPG decreased in group A but not in group B (16.5 +/- 1.3 to 11.8 +/- 1.5 mmHg, P < 0.01; 18.2 +/- 1 to 17 +/- 1.1 mmHg, P= 0.4). Systemic hemodynamics and liver function remained unchanged. In group A, but not in group B, VEGF decreased (21.2 +/- 4.7 to 13.7 +/- 3.5 pg/mL, P < 0.01; 22.5 +/- 7.8 to 19.2 +/- 5.4 pg/mL, P= 0.4). ET-1 remained stable. Changes in HVPG and VEGF were correlated (r = 0.49, P < 0.05).

CONCLUSIONS

Three months of long-acting octreotide in selected cirrhotic patients with portal hypertension decreases the HVPG independent of systemic hemodynamics and liver function. The decrease in VEGF blood levels suggests an improvement in splanchnic hyperemia.

Hepatology may have problems with putative surrogate outcome measures

A surrogate outcome measure is a laboratory measurement, a physical sign, or another intermediate substitute that is able to predict an intervention's effect on a clinically meaningful outcome. A clinical outcome detects how a patient feels, functions, or survives. Surrogate outcome measures occur faster or more often, are cheaper, and/or are less invasively achieved than the clinical outcome. In practice, validation is surprisingly often overlooked, especially if a biologic plausible rationale is proposed. Surrogate outcomes must be validated before use. The first step in validation is to demonstrate a correlation between the putative surrogate and the clinical outcome, e.g., the higher the surrogate the shorter time to death. However, a correlation is not sufficient to validate the surrogate. The second step is to establish if the intervention's effect on the surrogate outcome accurately predicts the intervention's effect on the clinical outcome. In hepatology a number of putative surrogate outcomes are used both in clinical research and in clinical practice without having been properly validated. Sustained virological response to interferons and ribavirin in patients with chronic hepatitis C, serum bilirubin concentration following ursodeoxycholic acid or immunosuppressants for patients with primary biliary cirrhosis, and nutritional outcomes following artificial nutrition for liver patients may not be valid surrogates for morbidity or mortality. The challenge is to develop reliable surrogates, both to facilitate the development of new interventions and to ensure our patients and us that these interventions are effective clinically.