A Case of Heparin-Induced Thrombocytopenia Type 2 after Repair of Juxtarenal Abdominal Aortic Aneurysm.

Heparin-induced thrombocytopenia (HIT) is still a relatively uncommon condition and it is not well known how to administer argatroban during continuous hemodiafiltration (CHDF). A 72-year-old man required CHDF with heparin because of the oliguria and hyperpotassemia directly after the open repair of a juxtarenal abdominal aortic aneurysm. As the postoperative blood platelet count dropped and there was a thrombus in the CHDF circuit, HIT was suspected and nafamostat mesilate, but not heparin, was immediately administered for CHDF. As heparin-platelet factor 4 complex was positive, we diagnosed him with HIT and started argatroban while monitoring the activated clotting time (ACT), resulting in no further obstruction of the CHDF and an increase in the platelets. There was no disadvantage for administering nafamostat mesilate which we have commonly used instead of heparin, we should have used argatroban once we suspected HIT. It may be important to consider the history of heparin especially in administering heparin and it may be useful to monitor the ACT when initially starting argatroban for patients with HIT.