Liver Disease Common After Fontan Procedure

By Will Boggs, MD

August 20, 2020

NEW YORK (Reuters Health) - Most patients will develop liver fibrosis after their Fontan procedure, and many will require heart-liver transplants, according to a new review.

"Fontan-associated liver disease (FALD) is underdiagnosed," Dr. Juliet Emamaullee of Children's Hospital-Los Angeles' Liver Transplant Center told Reuters Health by email. "It does not present with the same lab derangements and physical-exam findings that are familiar for other types of chronic liver disease."

"The degree of fibrosis on liver biopsy is the best indicator of severity of liver disease and can guide a clinician in how to monitor the patient, when to refer to hepatology, and also counsel the patient on lifestyle considerations for patients with chronic liver disease (i.e., avoid alcohol, impact of obesity/fatty liver, hepatotoxic medications, etc.)," she said.

In a report in Circulation, Dr. Emamaullee and colleagues describe the epidemiology, clinical diagnosis, and options for monitoring progression and treatment in patients with FALD.

The Fontan procedure involves implantation of a surgical shunt to divert blood from the inferior vena cava and superior vena cava to the pulmonary arteries, essentially placing the systemic and pulmonary circulations in series with a functional single ventricle. This results in chronic hepatic congestion secondary to high-pressure nonpulsatile flow in the inferior vena cava.

As a result of these physiologic changes, virtually 100% of patients develop histologic evidence of fibrosis, and 40% have bridging fibrosis at 10 years post-Fontan.

Diagnosis and monitoring of FALD can be challenging, because most patients will have no detectable abnormalities on physical examination and few will have abnormal liver laboratory findings.

Ultrasound, CT and MRI have been used to detect findings suggestive of cirrhosis and its complications, and elastography using one of these approaches may be useful for patient evaluation and management in the Fontan population, as it detects not only hepatic fibrosis but also congestive hepatopathy from hepatic venous outflow obstruction, the authors say.

They propose an algorithm for monitoring the development and progression of FALD, which begins with surveillance liver biopsy at 10 years post-Fontan for patients with no clinical evidence of chronic liver disease and with hepatology referral and other testing, including MRI elastography, for patients >3 years post-Fontan with clinical concerns for chronic liver disease.

Once high-grade fibrosis occurs in a post-Fontan patient, strategies can be implemented to lower right-sided heart pressures and improve hepatic venous outflow. While heart transplantation alone might stabilize FALD, combined heart-liver transplantation appears to yield superior long-term outcomes, although experience with this procedure remains limited, according to the report.

"Since there are 70,000 of these patients worldwide, most of whom are <25, there will be an increasing need to monitor the liver and be ready to consider combined heart and liver transplantation," Dr. Emamaullee said. "Essentially, physicians who take care of these patients need to be aware of FALD, understand how to screen, diagnose, and monitor it, and refer patients with FALD early to liver specialists, ideally affiliated with an experienced transplant program, for surveillance."

"On the flip side, liver transplant programs need to become familiar with these patients and be prepared to work with the cardiologists/heart transplant folks to co-manage these patients," she said.

"The multidisciplinary management of congenital heart disease has allowed for excellent outcomes and survival into adulthood," Dr. Emamaullee said. "The next challenge is becoming familiar with FALD and preparing for multidisciplinary management, including the potential for combined heart-liver transplantation."

SOURCE: Circulation, online August 11, 2020.