Prophylactic portacaval anastomosis in cirrhotic patients with esophageal varices and ascites. Experimental design and preliminary results

Primary prevention of variceal bleeding in people with oesophageal varices due to liver cirrhosis: a network meta-analysis

BACKGROUND

Approximately 40% to 95% of people with cirrhosis have oesophageal varices. About 15% to 20% of oesophageal varices bleed in about one to three years. There are several different treatments to prevent bleeding, including: beta-blockers, endoscopic sclerotherapy, and variceal band ligation. However, there is uncertainty surrounding their individual and relative benefits and harms.

OBJECTIVES

To compare the benefits and harms of different treatments for prevention of first variceal bleeding from oesophageal varices in adults with liver cirrhosis through a network meta-analysis and to generate rankings of the different treatments for prevention of first variceal bleeding from oesophageal varices according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers to December 2019 to identify randomised clinical trials in people with cirrhosis and oesophageal varices with no history of bleeding.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) in adults with cirrhosis and oesophageal varices with no history of bleeding. We excluded randomised clinical trials in which participants had previous bleeding from oesophageal varices and those who had previously undergone liver transplantation or previously received prophylactic treatment for oesophageal varices.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods and calculated the differences in treatments using hazard ratios (HR), odds ratios (OR), and rate ratios with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute for Health and Care Excellence Decision Support Unit guidance. We performed the direct comparisons from randomised clinical trials using the same codes and the same technical details.

MAIN RESULTS

We included 66 randomised clinical trials (6653 participants) in the review. Sixty trials (6212 participants) provided data for one or more comparisons in the review. The trials that provided the information included people with cirrhosis due to varied aetiologies and those at high risk of bleeding from oesophageal varices. The follow-up in the trials that reported outcomes ranged from 6 months to 60 months. All but one of the trials were at high risk of bias. The interventions compared included beta-blockers, no active intervention, variceal band ligation, sclerotherapy, beta-blockers plus variceal band ligation, beta-blockers plus nitrates, nitrates, beta-blockers plus sclerotherapy, and portocaval shunt. Overall, 21.2% of participants who received non-selective beta-blockers ('beta-blockers') - the reference treatment (chosen because this was the most common treatment compared in the trials) - died during 8-month to 60-month follow-up. Based on low-certainty evidence, beta-blockers, variceal band ligation, sclerotherapy, and beta-blockers plus nitrates all had lower mortality versus no active intervention (beta-blockers: HR 0.49, 95% CrI 0.36 to 0.67; direct comparison HR: 0.59, 95% CrI 0.42 to 0.83; 10 trials, 1200 participants; variceal band ligation: HR 0.51, 95% CrI 0.35 to 0.74; direct comparison HR 0.49, 95% CrI 0.12 to 2.14; 3 trials, 355 participants; sclerotherapy: HR 0.66, 95% CrI 0.51 to 0.85; direct comparison HR 0.61, 95% CrI 0.41 to 0.90; 18 trials, 1666 participants; beta-blockers plus nitrates: HR 0.41, 95% CrI 0.20 to 0.85; no direct comparison). No trials reported health-related quality of life. Based on low-certainty evidence, variceal band ligation had a higher number of serious adverse events (number of events) than beta-blockers (rate ratio 10.49, 95% CrI 2.83 to 60.64; 1 trial, 168 participants). Based on low-certainty evidence, beta-blockers plus nitrates had a higher number of 'any adverse events (number of participants)' than beta-blockers alone (OR 3.41, 95% CrI 1.11 to 11.28; 1 trial, 57 participants). Based on low-certainty evidence, adverse events (number of events) were higher in sclerotherapy than in beta-blockers (rate ratio 2.49, 95% CrI 1.53 to 4.22; direct comparison rate ratio 2.47, 95% CrI 1.27 to 5.06; 2 trials, 90 participants), and in beta-blockers plus variceal band ligation than in beta-blockers (direct comparison rate ratio 1.72, 95% CrI 1.08 to 2.76; 1 trial, 140 participants). Based on low-certainty evidence, any variceal bleed was lower in beta-blockers plus variceal band ligation than in beta-blockers (direct comparison HR 0.21, 95% CrI 0.04 to 0.71; 1 trial, 173 participants). Based on low-certainty evidence, any variceal bleed was higher in nitrates than beta-blockers (direct comparison HR 6.40, 95% CrI 1.58 to 47.42; 1 trial, 52 participants). The evidence indicates considerable uncertainty about the effect of the interventions in the remaining comparisons.

AUTHORS' CONCLUSIONS

Based on low-certainty evidence, beta-blockers, variceal band ligation, sclerotherapy, and beta-blockers plus nitrates may decrease mortality compared to no intervention in people with high-risk oesophageal varices in people with cirrhosis and no previous history of bleeding. Based on low-certainty evidence, variceal band ligation may result in a higher number of serious adverse events than beta-blockers. The evidence indicates considerable uncertainty about the effect of beta-blockers versus variceal band ligation on variceal bleeding. The evidence also indicates considerable uncertainty about the effect of the interventions in most of the remaining comparisons.

Prophylactic sclerotherapy before the first episode of variceal hemorrhage in patients with cirrhosis

The value of sclerotherapy as prophylaxis against the first episode of variceal hemorrhage has not been established. Therefore, we randomly assigned 133 patients with cirrhosis of the liver (of alcoholic origin in 66 percent), esophageal varices, and no previous intestinal bleeding to either prophylactic sclerotherapy (n = 68) or no prophylaxis (n = 65). The groups were comparable in hepatic function, endoscopic findings, and the pathogenesis of cirrhosis. All patients who subsequently had a first episode of variceal hemorrhage received sclerotherapy whenever possible. During a median follow-up of 22 months, variceal hemorrhage occurred in 28 percent of the patients receiving sclerotherapy and 37 percent of the controls (P = 0.3). Thirty-five percent of the sclerotherapy group and 46 percent of the control group died. The survival curves (Kaplan-Meier) of both groups were similar (P = 0.2). However, among patients with alcoholic and moderately decompensated cirrhosis (Child-Pugh group B), survival was significantly higher in those receiving sclerotherapy, although the risk of bleeding was only marginally reduced by this procedure. We conclude that prophylactic sclerotherapy does not significantly reduce the risk of bleeding from esophageal varices, but that a subgroup of patients with esophageal varices and moderately decompensated alcoholic cirrhosis may benefit from prophylactic sclerotherapy because of factors not solely attributable to prevention of an initial episode of variceal bleeding.

Prophylaxis of first variceal hemorrhage in patients with liver cirrhosis

Prophylaxis of bleeding from esophageal varices is a very tempting concept at first glance, especially under the assumption of a high mortality associated with first variceal hemorrhage. Up to now four different measures have been tried for prophylaxis: portacaval shunt operation, devascularization procedures, sclerotherapy, and drugs. With the exception of portacaval shunts, ongoing controlled trials show a weak trend toward reduction of variceal bleeding and prolongation of survival in selected patients with compensated cirrhosis and large varices. However, prophylaxis of first variceal bleeding must still be regarded as experimental and should be restricted to controlled clinical studies.

Ascites: its correction by peritoneovenous shunting

Patients with refractory ascites and HRS should be considered to present an urgent indication for peritoneovenous shunting. The shunt offers a method of continuous reinfusion of ascitic fluid which corrects avid sodium retention, oliguria and azotemia. Severe encephalopathy, jaundice or peritoneal sepsis--common complications of cirrhosis--contraindicate installation of the shunt before improvement occurs. Associated cardiac disease does not contraindicate the use of the shunt provided that ascitic fluid is removed at the time of operation and large amounts of diuretics are used. This operation has also proved useful in ascites attributed to causes other than cirrhosis. The main complications include disseminated intravascular coagulopathy, hepatic coma and sepsis in a few patients. Results of a randomized prospective study indicate that the shunt should probably be considered in patients with diet-resistant massive ascites even before they prove to be refractory to diuretic therapy.

[Management of a systematic follow-up clinic (author's transl)]

The essential differences between the common, irregular medical check-up, as practiced in the follow-up clinics in England and Scandinavia, and the type practiced in the systematic follow-up clinic in the "Marburg experiment" are presented with examples. The necessity of the latter for clinical knowledge, for the attending surgeon, for special patients, and last but not least, for clinical research, is stressed. Based on examples from the Marburg systematic follow-up clinic for duodenal ulcer studies, its practicability is discussed.

Propranolol disposition in chronic liver disease: a physiological approach

The pharmacokinetics of propranolol can be quantitatively explained on a physiological basis from a knowledge of the effects of four biological determinants: (1) the activity of the drug metabolising enzymes (intrinsic clearance); (2) hepatic blood flow; (3) drug binding, and (4) the anatomical arrangement of the hepatic circulation. Distrubances of all these determinants can occur in chronic liver disease and result in predictable changes in propranolol disposition. These changes, as well as those occurring with other drugs in chronic liver may be explained by 'intact hepatocyte theory' which postulates that the major pathophysiological change occurring in compensated chronic liver disease is a reduction in relatively normally perfused and functioning cell mass with the development of intrahepatic portasystemic vascular shunts.

Changing patterns of gastrointestinal manifestations of cystic fibrosis. Survey of recent progress in diagnosis and treatment

As advances in management continue to improve the chances of survival, older patients have more expressions of disturbed function within the gastrointestinal tract. These in turn call for new forms of treatment, physiologically derived.