Every year in southern Alberta, about 400 babies are born with congenital heart disease. It is the most common birth defect in children and a disease that often requires a lifetime of care. Many need surgery to survive.
One of the surgeries, called the Fontan procedure, is a series of operations to redirect the blood flow and circulation within the child's partially functioning heart. The procedure is life-saving, but over time Fontan recipients experience another life-threatening problem — a failing liver.
Complications develop after life-saving procedure
“Children develop abnormalities in the liver due to elevated venous pressure and low cardiac output because of the Fontan circulation,” says Dr. Steven Greenway, a researcher who is collaborating with European colleagues to find ways to help these children.
Greenway is a paediatric cardiologist at the Alberta Children’s Hospital and an assistant professor in the Cumming School of Medicine’s departments of Paediatrics, Cardiac Sciences and Biochemistry & Molecular Biology. He is also a member of the university’s Alberta Children’s Hospital Research Institute and Libin Cardiovascular Institute of Alberta.
“The Fontan procedure causes problems for these young patients as they may eventually develop cirrhosis, cancer and liver failure, potentially fatal,” he says.
According to Greenway, there is a real need to find early clues of liver damage to give clinicians guidance on how to manage their outcomes.
More research needs to be conducted for reliable screening
Greenway and a team of researchers from the Freeman Hospital in Newcastle, United Kingdom and the University of Calgary studied tests used in viral hepatitis to see if these were applicable in diagnosing liver damage in Fontan patients.
“Unfortunately, we found that because of the surgically-created circulation, the Fontan liver is congested and this interferes with test interpretation,” he says.
The researchers found that even the most reliable methods of screening for liver damage in adults, including laboratory blood tests, biopsies and non-invasive imaging, are not easily correlated with the true extent of liver damage in Fontan patients.
“This indicates to the transplant community that more research needs to be conducted to find more reliable screening than currently available,” he says.
Recommendations on when to proceed to heart transplantation
The study, headed by Greenway, led to a literature review and expert recommendations by the Calgary team collaborating with the clinicians from the Freeman Hospital to identify when a young patient should proceed to a heart transplantation. The researchers also recommended that all Fontan patients receive screening for liver disease on an annual basis. The paper was recently published in the Journal of Heart and Lung Transplantation.
"This research aims to show how clinicians can manage care of young patients with Fontan, so that early signs of liver damage can be considered when recommending a heart transplant,” says Greenway.
There is very little literature on Fontan patients, although more studies are being conducted as an increasing number of them are surviving into adulthood and being referred for heart transplantation.
The other researchers in this study are Dr. D. Crossland, (U.K.); Dr.Mark Hudson, (U.K.); Dr. Steven Martin, CSM Department of Paediatrics; Dr. Robert Myers, CSM Department of Medicine; Dr. Tim Prieur, CSM Department of Cardiac Sciences and Libin Cardiovascular Institute; Asif Hasan, (U.K.); and Richard Kirk (U.K.).
Chronic diseases, infections, and inflammatory states together with pain create the greatest burden on health care in the world. The University of Calgary’s Infections, Inflammation and Chronic Diseases in the Changing Environment research strategy brings together multidisciplinary teams and top scientists to understand and prevent the complex factors that threaten our health and economies.