Surgical reexploration after cardiac operations: why a worse outcome?

Surgical reexploration due to postoperative bleeding occurs in 2% to 6% of cardiac surgical patients and is accompanied by increased morbidity and mortality. In this study, we addressed the postoperative course of patients needing surgical reexploration, with specific respect to the timing of reexploration and the transfusional needs as determinants of morbidity and mortality.

This was a retrospective study of 232 patients having undergone surgical reexploration owing to postoperative bleeding after cardiac operations, compared with a control, propensity-matched group.

Patients in the surgical reexploration group had greater morbidity (low cardiac output, acute renal failure, sepsis) and longer mechanical ventilation time and intensive care unit stay than did control patients, and a significantly higher mortality rate (14.2% versus 3.4%, p = 0.001). The timing of surgical reexploration was not associated with morbidity or mortality. The amount of packed red cells transfused was significantly associated with increased morbidity (acute renal failure, low cardiac output syndrome, sepsis), with mechanical ventilation time and intensive care unit stay, and with the mortality rate (0.25% increase for each unit transfused).

The main determinant of morbidity and mortality for patients requiring a surgical reexploration after cardiac operations is the amount of packed red cells transfused. Delaying the timing of reexploration may represent a risk factor only when the delay creates the need for an excessive use of allogeneic blood products, or in the presence of clinical signs of cardiac tamponade.