A homograft (also called an allograft) is a tissue or organ transplant taken from another human being. In cardiac surgery, the term most commonly refers to a homograft heart valve: a valve (typically the aortic or pulmonary valve along with its root and attached tissue) removed from a human donor heart after death, preserved, and used as a replacement in a recipient patient.
Homograft valves have several clinical advantages. Because the tissue is human in origin, it does not require the lifelong anticoagulation that mechanical (metal) prosthetic valves necessitate. This makes them particularly valuable in patients for whom anticoagulation is problematic: women of childbearing age, children, and patients with active valve infection (endocarditis). Homograft valves also provide good haemodynamic performance with minimal obstruction to blood flow.
The main disadvantage of homograft valves is limited durability. They deteriorate structurally over time, typically lasting 10 to 20 years in adults and often less in children, where growth accelerates calcification. Re-operation for a failed homograft is technically more complex than the original procedure, and tissue availability can limit their use.
In complex congenital heart surgery (such as pulmonary atresia or the Ross operation), homografts are frequently used as right ventricular outflow tract conduits. Patients with homograft implants are followed up in specialist cardiac centres with regular imaging to monitor the conduit.
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