[Studies of intraoperative plateletapheresis in cardiovascular surgery]

We evaluated the effect of intraoperative plateletapheresis (IPA) on platelet dysfunction associated with cardiopulmonary (C-P) bypass in 49 patients for open heart or great vessel surgery. Autologous platelet concentrated (PC) (16.6 +/- 6.1 units) was collected before the start of C-P bypass and was reinfused after protamine administration. Platelet aggregability after PC reinfusion was significantly greater in IPA group (n = 13) than in non-IPA group (n = 15). Platelet count and ionized calcium level were lower in the IPA group temporarily after PC collection. No differences were noted in hemodynamic variables, WBC count and hemoglobin between the two groups. Plasma IL-6, which increased slightly after PC collection, showed a great increase after C-P bypass in both IPA (n = 8) and non-IPA (n = 8) groups. In in vitro experiments, platelet aggregability was reduced with the increase of centrifugal force over 800 x g during PC separation (n = 10) and with the prolongation of PC preserving time over 4 hours (n = 11). The result of this study demonstrates the significance of plateletapheresis in post-bypass platelet function and hemostasis, although further improvements are needed for collection and preservation of PC.