To celebrate February as American Heart Month, the News Blog is highlighting some of the latest heart-centric news and stories from all parts of Penn Medicine.
Due to the complex, interdependent nature of the human body’s internal organs, transplant specialists are constantly working to develop new procedures for disorders that extend beyond a single organ. Increasing success with single solid-organ transplantation over the last 50 years has helped propel the field into the more complicated realm of multi-organ transplantation. The first dual-organ transplant, which provided a 6-year-old Texas girl with a new heart and liver, took place on Valentine’s Day in 1984, but just over 100 heart-liver transplants have been performed in the nearly three decades since. Penn Medicine transplant physicians are at the forefront of this work, performing 19 of these combination transplants since 2002 – the second largest number of any transplant center in the U.S., most of whom have only done one or two of the procedures.
For patients with rare and debilitating conditions, simpler options are often limited – dual-transplantation can be the difference between life and death.
According to Alberto Pochettino, MD, associate professor of Cardiothoracic Surgery and director of the Lung Transplant Program and co-surgical director of the Adult Congenital Heart Disease Program at Penn Medicine, most patients who are considered for the dual heart-liver procedure are in their 20s or 30s and were born with a cardiac defect in which one of the two ventricles in the heart is normal, while the other is extremely small or absent entirely. Several conditions can lead to this malformation, the most common of which is Hypoplastic Left Heart Syndrome (HLHS), in which parts of the left side of the heart fail to develop completely. HLHS affects two of every 10,000 children born – about 7 to 9 percent of all congenital heart defects – but without proper care and immediate attention, the condition is fatal.
With only one normal ventricle, surgeons typically perform an early surgery that changes an HLHS patient’s blood circulation so they become dependent on the one normal ventricle. Blood that would usually be delivered to the lungs through the absent ventricle can be rerouted so that the lungs receive blood passively, without the assistance of a ventricle to pump blood into the lungs.
Patients can live with this passive circulation for years and years, but in order to have passive flow to the lungs, they often have slightly elevated pressure to get the blood down to the lungs. When that pressure remains elevated over the course of 20 years or so, the liver can suffer irreversible damage, resulting in advanced liver disease.
But without a healthy heart, patients cannot be placed on the liver transplant list alone, since most would not survive the operation. Furthermore, chronic venous hypertension can impair intestinal function, making it difficult for many of these patients to absorb vital nutrients – particularly protein - from the food they eat every day. “The patients who come to us have often been debilitated, malnourished, and in profound heart failure for quite some time,” says Pochettino. Though some patients may improve with a heart transplant alone, the amount of liver damage may not be reversible, and it is often impossible for the intestine to recover without a liver transplant as well.
“For patients who have this combination of single-ventricle congenital heart disease, liver disease, and the inability to properly absorb proteins in the intestine, the most reliable solution we have is the combined heart-liver transplant,” says Pochettino. Although the procedure is a much bigger surgery than a heart transplant alone, patients who receive both seem to have a much better chance at a full recovery, he said. “Without a healthy liver and intestine, these patients will die.”
From start to finish, a combined heart-liver transplant can take anywhere from eight to 12 hours During the operation, the cardiac transplant team implants the new heart first, before the liver team steps in to start the liver transplant procedure, a process which on its own can take four hours or more.
Though the number of heart-liver transplant recipients remains a small group, preliminary results may suggest that these patients will have a lower organ rejection rate than those who receive only a heart transplant, potentially giving the dual-organ recipients a longer survival. Research is ongoing, but Pochettino says the indications are positive.
And since more patients with these types of congenital heart defects are living into adulthood than ever before due to the development of early-childhood corrective surgeries – which have only been in use since the 1980s – the number of patients who are expected to need a heart-liver transplant in the coming years is growing. “There are a lot of patients out there who are currently surviving and might be doing okay with the passive circulation for now, but presumably at some point, that will fail and many of them will probably need this operation.”