Methods: The study comprised all patients undergoing cardiopulmonary bypass (CPB) during open heart surgery and OPCAB procedure between January 1995 - December 2004 (13051 operations). Patients were divided into six groups as follows; valve replacement±Coronary artery bypass grafting (CABG), CABG-CPB, OPCAB, congenital operations with cardiopulmonary bypass, ascending and/or arcus aortic surgery and others. Overall reexploration rate for bleeding was assessed for each group (165 revisions; 130 males, 35 females; mean age 53.1±16.8 years; range 5 to 84 years).

Results: Overall reexploration rate for bleeding was 1.2% (165/13051) in ten years period. The reexploration rate was 1.1% (67/6120) during the first 5-year period (1995-1999) and 1.4% (98/6931) during the second 5-year period (January 2000-December 2004). In subgroup analysis; reexploration rate was highest in the ascending and arcus aortic surgery subgroup (4.7%) and lowest in the OPCAB subgroup (0.9%). Overall in-hospital mortality rate was 6.6% (11/165). Early revision rate was 84% (139/165) and late revision rate was 16% (26/165). Nineteen of the 26 patients in late revision group were on oral anticoagulant treatment due to mechanical valve replacement.

Conclusion: Reexplorations rate for bleeding has increased from 1.09% to 1.4% during the second 5-year period. This may be due to an increase in the number of patients in urgent or emergent conditions or to the increase of the number of patients with worse preoperative conditions than before. Echocardiographic examination in patients with replaced mechanical valves and on oral anticoagulants in the early postoperative period would reveal the presence of pericardial effusion. This would be useful to determine the necessity of surgical intervention in the follow-up period.