With the patient under general anaesthesia, the heart is accessed by a sternotomy and cardiopulmonary bypass is established. The heart is stopped with cardioplegic arrest, the aorta is opened and the valve is inspected. The diseased valve cusps are carefully removed and the intercommissural distances are measured. Commercially available bovine pericardium is trimmed to the desired size using a template, and sutured to the annulus to replace the removed cusp(s). The aorta is closed, normal circulation is restored and the chest is closed. The function of the valve is assessed intraoperatively by transoesophageal echocardiography.