Data from our internal prospective registry shows an increasing incidence of patients with renal complications. In 2008 temporary dialysis was necessary in 7% of the patients (76/1130) and in 19% of the patients a postoperative increase of S-creatinine > 200 μmol/l was observed, mirroring a reduction in kidney function of 60-70%. We assume that the kidney function is completely normalized over time, but this is actually not known because these patients are not routinely controlled on a cardiac surgery outpatient basis. Currently, we are gathering 1-year outcome data on patients, who have undergone postoperative dialysis in 2008.