CEA術前血小板凝集能検査の有用性  [in Japanese] Preoperative Analysis of Platelet Aggregability in Carotid Endarterectomy  [in Japanese]

Although antiplatelet therapy is usually continued throughout the perioperative period of carotid endarterectomy to reduce the risk of recurrent stroke and other cardiovascular events, individualization still has not been standardized. To evaluate the relationship between preoperative antiplatelet agents and platelet aggregability, we analyzed 42 patients who underwent carotid endarterectomy from August 2005 to May 2006 in our institute. Among the 42, 19 were treated with aspirin alone, 5 with ticlopidine alone, 2 with cilostazol alone, 12 with aspirin and ticlopidine, 3 with aspirin and cilostazol and 1 with aspirin, ticlopidine, and cilostazol. Platelet aggregation in response to platelet agonist was measured in platelet-rich plasma obtained from the brachial vein 2 days prior to surgery. 1 μM and 10 μM ADP, or 2 μg/ml and 5 μg/ml collagen were used as agonists. Aggregation in response to appropriate agonist was inhibited in 73% of the aspirin group and 80% of ticlopidine group. None of the cilostazol group showed effects on aggregability. Patients were divided into 2 groups according to their preoperative platelet aggregability: inhibited (n=3) or non-inhibited (n=39). Intraoperative blood loss was 169.0± 23.3 g (144-190 g) or 45.5±31.2 g (9-164 g), respectively. Operation time was 221.7±53.5 min (160-255 min) or 147.3±20.6 min (115-205 min), respectively. The main reason for blood loss and prolonged operation time was oozing from connective tissue. Aggregability in older patients who received multiple antiplatelet agents tended to be inhibited excessively. Taken together, preoperative analysis of platelet aggregability could be useful to reduce the risk of perioperative complication.