Heparin-induced thrombocytopenia in a case of endovascular aneurysm coiling.

We report a case of 46-year-old man who underwent endovascular coil embolization for left anterior inferior cerebellar and posterior inferior cerebellar aneurysms. During embolization of both aneurysms, thrombotic complications were observed along with a relative lack of response to heparin. Intra-arterial abciximab was used to recanalize an almost completely occluded posterior inferior cerebellar artery. A marked decrease in platelet counts was found soon after embolization, which normalized within a few days. Serologic tests confirmed heparin-induced thrombocytopenia. This syndrome should be considered in cases with thromboembolic complications during endovascular procedures, particularly in patients undergoing repeated heparin exposure. A sudden decrease in platelet counts and lack of response to heparin, manifested as a relative lack of increasing activated clotting time, should make one suspect this syndrome.