[Annuloaortic ectasia associated with antithrombin III deficiency; report of a case].

A 33-year-old male with hereditary deficiency of antithrombin III (AT III) was diagnosed with annuloaortic ectasia and scheduled for the aortic root replacement. As perioperative anticoagulation, AT III was administered to have its activity≥70% in addition to heparin. During the operation with cardiopulmonary bypass, 3,000 IU of AT III concentrate was infused, and there was no hemorrhagic complication. After the operation low-molecular-weight heparin was used instead of unfractionated heparin to avoid bleeding. However, renal infarction occurred on postoperative day 11. Heparin was continuously given in combination with 1,500 IU/day of AT III concentrate until oral warfarin reached within therapeutic range. The patient recovered without further sequelae. Cardiac surgery might be safely performed in patients with AT III deficiency by replenishing AT III concentrate to keep its activity higher than 80%.