150 U/kg heparin was administered intravenously at the beginning of graft anastomosis and accepted a perioperative ACT value of around 300 s. Ten minutes after the loading dose, the ACT was measured. An ACT of 300 s or greater was considered as adequate. Then follow up ACT measurement was determined after 30 min from the previous ACT measurement. If ACT fell below the target value of 300 s, an additional dose of heparin was administered. If ACT was between 250 and 299 s, additional 2000 U of heparin was administered and if ACT was between 200 and 249 s then additional 3000 U of heparin was injected. Ten minutes after additional heparin injection, ACT was remeasured.