Development of 4D Flow MRI for Risk Stratification of Variceal Bleeding in Cirrhosis
University of Wisconsin, Madison
Summary
The goal of this research is to validate novel non-invasive Magnetic resonance imaging (MRI) biomarkers to detect Gastroesophageal varices (GEV) in patients with cirrhosis, including fractional flow change in the portal vein and elevated azygos flow. End-stage liver disease (cirrhosis) is characterized by advanced fibrosis, liver failure, and portal hypertension. There are many causes of cirrhosis, including viral hepatitis, alcohol abuse, and perhaps most importantly, non-alcoholic fatty liver disease (NAFLD) and its aggressive subset, non-alcoholic steatohepatitis (NASH). 3 million new cases of end-stage liver disease (cirrhosis) are expected over the next decade. In cirrhosis, portosystemic collaterals that shunt blood away from the liver develop due to increased portal pressure. Gastroesophageal varices (GEV) are the most clinically relevant because they can cause fatal internal bleeding. GEV bleeding carries \~20% mortality at 6 weeks, and \~34% overall mortality. Identification of at-risk varices, prior to bleeding, is of paramount importance to initiate primary prophylaxis. To identify and treat at-risk patients, current guidelines recommend regular esophagogastroduodenoscopy (EGD) and variceal band ligation. Detection of high-risk GEV is key to initiating primary prophylaxis, which can reduce mortality by 50-70%. However, endoscopy is invasive and often unnecessary when no treatment is required. Therefore, the American Association for the Study of Liver Diseases has identified the development of "non-invasive markers that predict the presence of high-risk varices" as a major unmet need.
Description
The overall goal of this research is to implement advanced non-invasive 4D flow MRI biomarkers to predict the presence of treatable but potentially lethal GEV in patients with cirrhosis. This would facilitate the triage of patients with high-risk GEV to therapeutic EGD, while reducing unnecessary EGD procedures in patients without them. The primary biological mechanism for development of GEV is elevated portal pressure and reversal of flow in the left gastric vein (LGV). Applying 4D flow MRI, investigators aim to detect and quantify reversed flow in the LGV to detect GEV at risk for bleeding.…