Change of Platelet Aggregation During the Cessation of Antiplatelet Therapy in Patients with Cerebrovascular Reconstruction Surgery

Abstract

We examined how the effects of antiplatelet agents changed after their discontinuation before surgery in terms of platelet aggregation capacity. The study population comprised 35 patients with cerebral ischemia who were about to undergo cerebrovascular reconstruction surgery (Carotid EndoAtherecyomy; 22 patients underwent CEA, and 13 underwent STA-MCA bypass surgery). Preoperatively, they received aspirin (22 patients), clopidogrel (9 patients), or cilostazol (4 patients). The antiplatelet agents were discontinued 3-4 days before surgery and restarted on the day following surgery. On the day of surgery, the percent change rate of the maximum platelet aggregability rate increased to 130% compared with the level during the antiplatelet therapy in the patients receiving aspirin, but it remained as low as 32% in the patients receiving clopidogrel. Almost all patients resumed their pre-discontinuation levels of platelet aggregation after the restart of antiplatelet therapy. None of the 35 patients experienced difficulty in hemostasis during surgery or cerebral infarction or myocardial ischemia during or after surgery.
The changes in platelet aggregation rate observed with the use of a selected appropriate inducer reflected patient statuses after discontinuation and restart of antiplatelet therapy. This may be a useful index for monitoring patients undergoing cerebrovascular reconstruction surgery.