Background: Acute-on-chronic liver failure (ACLF) is a recently discovered syndrome, which is understood as an acute deterioration of decompen-sated liver cirrhosis. It is defined on the basis of organ failure(s) and associated with high short-term mortality. ACLF is caused by a precipi-tating event that results in excessive systemic inflammation. ACLF is mostly precipitated and associated with bacterial infections but 40-50% of the underlying cause is unclear. Surgery, with or without liver involvement, has been defined as such a precipitating event. It is long known, that surgery in liver cirrhotic patients, depending on stage of cirrhosis as well as on type of surgery, bears a great risk but is still in-evitable in some cases. Child-Turquotte Score has been used for risk stratification of postoperative mortality. The development and out-come of ACLF after surgical interventions have not been characterized yet. In addition, underlying causes as well as molecular mechanism leading to ACLF after surgical intervention have not been identified. The aim of this trial is to further prospectively investigate patients with cirrhosis undergoing surgery to identify clinical markers and molecular mechanisms involved in development of ACLF.~Objectives: Defining precipitants and predictors of development of ACLF after surgical interventions, allowing to develop a risk stratification for elective procedures in cirrhotic patients.~Identifying molecular mechanisms of post-interventional ACLF and thus preparing the ground for development of new therapeutic approaches.~Study design: Prospective, observational study. Patients will be screened according inclusion/exclusion criteria. After informed consent sample processing will be possible from max. 1 week before scheduled surgery.~Primary endpoints: Development of ACLF within 28 and 90 days after visceral or non-visceral surgery in patients with portal hypertension (liver cirrhosis and idiopathic non-cirrhotic portal hypertension)~Secondary endpoints:~Mortality at 1 month, 3 months and 1 year.~Following endpoints will be evaluated:~ Time to death and mortality (overall and surgery-related)  Time to and rate of unplanned rehospitalizations after surgery  Any Infection and differentiated by site of infection (SBP, pneumonia, urinary tract infection, blood stream infection, Clostridium difficile-associated enterocolitis  Postsurgical acute hepatic decompensation and ACLF~To assess the changes in the intestinal microbiota in both groups and evaluate its effect on the primary endpoint.~To assess the potential socioeconomic impact.
Prospective, observational study to define precipitants and predictors of development of Acute-on-Chronic Liver Failure (ACLF) after surgical interventions, allowing to develop a risk stratification for elective procedures in cirrhotic patients. As well as identifying molecular mechanisms of post-interventional ACLF and thus preparing the ground for development of new therapeutic approaches.