Non-invasive Prediction of Esophageal Varices in Patients With Non-Alcoholic Fatty Liver Disease With Advanced Fibrosis

Overview

Non-alcoholic fatty liver disease (NAFLD) is defined as accumulation of fat in the liver which is not related to either alcohol excess or other causes such viral infection, immune-mediated, or medication related which can lead to fibrosis and later-on, cirrhosis. Over the last years NAFLD related liver cirrhosis has become the commonest cause of chronic liver disease worldwide. Portal hypertension is the major complication caused by increased splanchnic blood flow which leads to development of oesophageal varices (OV). Almost all of the patients with portal hypertension can develop OV sometime in their life and one third of those will bleed, hence identifying the presence of OV is a an important aspect of diagnostic workup of these patients with portal hypertension. Upper digestive camera test/endoscopy is the only means to diagnose and grade OV but endoscopy is an invasive procedure and its cost effectiveness for screening is also questionable. These limitations and the ever-increasing workload on endoscopy units has led many researchers to identify some parameters that can non-invasively diagnose OV. Researchers have proposed use of platelet count/spleen diameter ratio, liver stiffness on Fibroscan among many non-invasive tools to predict OV in patients with portal hypertension with success. Recently criteria proposed in Baveno VI conference, (Baveno-IV Criteria) recommended that screening endoscopy can be avoided in patients with compensated advanced chronic liver disease (cACLD) with liver stiffness measurement (LSM) less than 20 kPa and a platelet count more than than 150,000/μL with an expanded Baveno-IV criteria suggesting platelet count \>110 × 109 cells/L and LSM \<25 kPa can spare even more endoscopies with a risk of missing varices needing treatment (VNT) being minimal.

Background: Non-alcoholic fatty liver disease (NAFLD) is defined as fatty infiltration of the liver not related to alcohol excess or other usual causes of hepatic steatosis e.g. viral or autoimmune hepatitis or secondary to medications and includes a spectrum ranging from steatosis, steatohepatitis, and fibrosis to cirrhosis; and is now the most common cause of chronic liver disease worldwide with prevalence of up to 30%. Although most patients with NAFLD may not progress to advanced fibrosis or cirrhosis, but as it has become so prevalent that still many patients develop cirrhosis and is now a leading indication for liver transplantation in Europe. In terms of global prevalence of NAFLD, it is quite high (32%) in the Middle East region. Portal hypertension is the major complication caused by increased splanchnic blood flow secondary to vasodilation and increased resistance to blood flow through periportal fibrosis which leads to development of oesophageal varices (OV). An estimated 90% of the portal hypertension patients will develop OV sometime in their life and 30% of those will bleed. Moreover 5-50% of the patients with acute variceal bleed will die within first days of the initial episode,6 hence identifying the presence of OV is a fundamental part of diagnostic workup of portal hypertension patients. Upper digestive endoscopy is the only means to diagnose and grade OV but endoscopy is an invasive procedure and its cost effectiveness for screening is also questionable. These limitations and the ever-increasing workload on endoscopy units has led many researchers to identify some parameters that can non-invasively diagnose OV. The factor most commonly associated with varices in most of these studies was thrombocytopenia, though it lacked sensitivity and specificity. Previously researchers proposed normalizing the platelet count to ultrasonographic spleen diameter and used platelet count/spleen diameter ratio of 909 to predict OV non-invasively in patients with portal hypertension, with 100% prevalence adjusted negative predictive value, and further validation studies showed the generalisability of results. Recent criteria in Baveno-IV conference, (Baveno-IV Criteria), recommends that screening endoscopy can be avoided in patients with compensated advanced chronic liver disease (cACLD) with liver stiffness measurement (LSM) less than 20 kPa and a platelet count more than than 150,000/μL. A new expanded Baveno-IV criteria suggesting platelet count \>110 × 109 cells/L and LSM \<25 kPa, likely to spare even more endoscopies with a risk of missing varices needing treatment (VNT) of only 1.6% (95% confidence interval, 0.7%-3.5%) in patients within the criteria and 0.6% (95% confidence interval, 0.3%-1.4%) in the overall population of 925 patients with cACLD. Aim: The purpose of this study is to compare the ability of various non-invasive methods including Baveno-IV \& expanded Baveno-IV criteria, platelet count/spleen diameter, and platelet count/(spleen diameter + LSM), in prediction of VNT in NAFLD with advance liver fibrosis Patients \& Methods: We plan to include minimum 100 patients of NAFLD related liver fibrosis as per selection criteria All the patients with NAFLD related liver fibrosis confirmed on Fibroscan referred to Endoscopy Unit, Tawam Hospital for screening of esophageal varices fulfilling the selection criteria will be selected from medical records and their documented demographic data and data pertaining to history of present illness and positive physical signs will be obtained. The biochemical workup (bilirubin, prothrombin time, albumin, creatinine), ultrasound for presence of ascites and bipolar splenic diameter, and data for liver stiffness measurement and results of upper GI endoscopy will be obtained. The Baveno-IV criteria and expanded Baveno-IV criteria and platelet count (in /mm3) to spleen diameter (in mm) ratio will be calculated/applied in all these patients and compared with outcomes of gold standard i.e Endoscopy results. All this information will be collected in excel sheet for further transfer on statistical software for further analysis.