Assessment of 12 patients treated with anticoagulant therapy who received oral-maxillofacial surgery under general anesthesia

Abstract

Twelve patients who had been treated with anticoagulant therapy and received oral-maxillo-facial surgery under general anesthesia were studied. All patients had been taking warfarin, an anticoagulant. Warfarin was discontinued 4 to 5 days before surgery and switched to an intravenous infusion of heparin so that the activated partial-thromboplastin time would be 1.5 to 2.0 times higher than that of normal subjects. Heparin was discontinued 3 to 6 hours before surgery and was restarted as soon as hemostasis was confirmed postoperatively. Once oral intake was resumed, warfarin administration was restarted. Heparin was discontinued when the prothrombin time/international normalized ratio reached therapeutic levels. Anticoagulant therapy should be withdrawn when patients undergo oralmaxillofacial surgery under general anesthesia because postoperative bleeding can be difficult to treat. However, 7 days were required on average for the prothrombin time/international normalized ratio to reach therapeutic levels after restarting warfarin postoperatively. Since anticoagulant activity during this period is unstable, the risk of thromboembolism increases. Our findings suggested that complications due to thrombus formation could be prevented by switching treatment from warfarin to heparin and controlling anticoagulant activity perioperatively.