Equally increased hypercoagulability irrespective of using minimized or conventional ECC systems.

OBJECTIVE

Minimized extracorporeal circulation systems in coronary artery bypass may have less impairing effect on hematological parameters and bleeding compared to conventional systems. The aim of this study was to investigate whether the use of mini systems does result in an increased postoperative hypercoagulative status.

METHODS

Patients with increased risk of postoperative blood transfusion were randomly allocated to coronary bypass surgery using conventional or minimized extracorporeal circulation. Serial thrombelastographic analysis was performed preoperatively, at day 1 and 5.

RESULTS

Forty-six patients were included. In 56% of the patients in the experimental and in 62% in the control group an activated coagulation system, measured as maximal amplitude above normal reference was found preoperatively. This was normalized the day after operation. At day 5 a significant number of patients in the experimental group (p = 0.03) overshooted the preoperative maximal clot strength compared to the control group (p = 0.15); however, a direct intergroup analysis showed no difference. In both groups, hemoglobin levels and platelet counts decreased at day one after surgery. At day 5, hemoglobin was partly and platelets completely normalized. No differences were found with respect to transfusion needs.

CONCLUSION

Mini systems seem to induce at least an equal increased state of hypercoagulability after coronary surgery. No clinical relevant differences could be demonstrated. This could indicate that patients after using mini systems are not protected against a postoperative state of increased hypercoagulability.