Frank Cetta, Jr., MD
Introduction
In October of 2015 the group from the Mayo Clinic reported the long-term outcomes of 1,052 patients who had a Fontan operation. This publication covered the institution’s entire experience dating from 1973 through 2012. Thirty-year survival was <50% for this cohort of patients However, in the recent era, 10-year survival improved to 95%. The Fontan operation was paradigm shifting in that it allowed for definitive palliation for children born with complex single ventricle physiology. It has resulted in a functional lifestyle into adulthood for many of these patients. However, despite the successes of the last 40 years, these patients are not “cured” or “repaired.” At best, the Fontan operation should be considered “definitive palliation,” and these patients demand lifelong, meticulous follow-up at centers equipped to handle their multifactorial medical problems. While it is encouraging that the more recent cohort has a favorable 10-year survival rate compared to those operated in the 1970s and 1980s, the long-term morbidity related to the Fontan operation is significant.
More than 50% of patients had rhythm issues that required medication at 20-year follow-up, and at least 20% needed pacemaker implantation. Fontan revision or conversion was needed in 10% and late repair/replacement of an atrioventricular valve was required in 5% of patients. Protein-losing enteropathy is one of the most devastating issues related to post-Fontan physiology. The mortality from PLE was 72%. Five-year survival after diagnosis of PLE for patients with Fontan physiology has been 50%. There are newer data that suggest with modern treatment regimes this may be improved, but when one looks at an overall cohort study, the long-term survival in patients after Fontan with PLE is poor. Cardiac transplantation in the modern era offers a treatment that may reverse PLE for these patients. A small minority of these patients also suffers with plastic bronchitis. There are new treatment strategies to identify lymphatic abnormalities that may be amenable to embolization strategies. Ten to twenty years after Fontan operation, issues related to liver pathology have been noted in these patients. Imaging techniques of the liver have improved over the years. However, the ability to treat post-Fontan hepatic fibrosis and cirrhosis is still being investigated.
In another analysis, patients who were referred to Mayo and had their initial Fontan elsewhere were also included. This brought the total cohort up to 1,138 patients. In this group, 195 patients had postoperative liver imaging or laboratory data available for analysis. In this subgroup of 195 patients, the freedom from cirrhosis at 10, 20 and 30 years was 99%, 94% and 57%. One-fifth of these patients were diagnosed with cirrhosis. The occurrence of cirrhosis was incremental. This is an interesting subset of patients.
Previous work from Mayo has demonstrated that patients with single ventricle physiology may actually have onset of Hepatic Disease prior to Fontan operation. Over the last 5-10 years, there has been increased surveillance of liver function and liver imaging in patients after Fontan operation. Some of this imaging has become quite sophisticated. Magnetic Resonance Elastography (MRE) in patients who are able to have MRI performed is an emerging technique for these patients. MRE evaluates hepatic stiffness, and helps to identify lesions that may be targets for biopsy. Some institutions have routinely performed liver biopsy on all patients at 10 years after Fontan operation. The proper diagnostic algorithm is still debatable. Even more dubious at this time is the proper treatment regime for hepatic disease in patients after Fontan. There is some suggestion that chronic anticoagulation with warfarin may be protective from developing cirrhosis in patients after Fontan. However, the data thus far are too limited to make this conclusion. The next decade of research will need to focus on improved therapy for this subset of patients. The vast majority of post-Fontan patients show some signs of increased hepatic stiffness or early fibrosis. Predicting which ones will progress to cirrhosis and even more importantly, hepatocellular carcinoma, is the question that will need to be answered.
To read the full article, please go to the March 2016 Issue of CCT.