Mediastinitis following graft replacement of the ascending and total arch aorta is a fatal complication of cardiac surgery. When graft infection is suspected, one choice of treatment is to remove the infected prosthesis and replace it with a new one. However such a procedure seems to be very risky. We report 2 successfully treated cases of mediastinitis following graft replacement of the ascending and total arch aorta. In one case, we treated with primary sternal closure after debridement and omental flap implant. In another case, the wound was left open and irrigation with iodine solution was undertaken for 6 days. The sternum was closed with pectoralis major muscle flap implantation. When graft infection is not suspected, primary sternal closure with implantation of tissue flaps is recommended. When graft infection is strongly suspected, we prefer secondary sternal closure after open irrigation.

A 44-year-old man underwent total arch replacement for acute type A aortic dissection. He was treated postoperatively in the intensive care unit for acute renal failure and respiratory failure. Although recovery of organ functions was seen, an unexpected fall in platelet count (PLT) occurred abruptly on postoperative day (POD) 7. The patient was treated with gabexate mesilate and platelet transfusion because disseminated intravascular coagulation (DIC) was initially suspected. Nevertheless, PLT dropped rapidly below 1.0×10⁴/μl. We suspected heparin-induced thrombocytopenia (HIT) and stopped all heparin administration including flush solution for pressure monitoring lines. The platelet factor 4-reactive HIT antibody test was performed and we began to give intravenous argatroban, 60mg/day. However, PLT did not increase at all. Multiple organ failure developed and metabolic acidosis deteriorated rapidly resulting in death on POD 15. HIT antibody was positive on POD 13 and a definitive diagnosed of HIT was made. For those patients treated with heparin continuously or repeatedly, HIT may occur and increase the mortality risk if the diagnosis is delayed.