The impact of major perioperative renal insult on long-term renal function and survival after cardiac surgery.

Temporary renal replacement therapy (RRT) facilitates recovery from a major perioperative renal injury and, although RRT can improve the hospital outcome, it is not known as to whether it mitigates long-term renal sequelae. Therefore, we investigated the risk of long-term dialysis after RRT post-cardiac surgery. We analysed prospectively the data collected for all hospital survivors who received RRT following cardiac surgery between March 1996 and July 2010, excluding those on dialysis preoperatively or with a functioning renal transplant. The follow-up data were obtained for all surviving patients. The mean age of the 82 patients was 68.6 ± 9.9 years, and 60 (73%) were male. Severe pre-existing renal dysfunction with a serum creatinine level of >200 μmol/l was present in 15 (18%) patients and diabetes in 31 (38%) patients. Operative procedures included redo surgery (n = 11, 13%) and thoracic aortic surgery (n = 9, 11%). During a 13.4-year follow-up, there were 38 late deaths. Only three patients with severe preoperative renal dysfunction received dialysis. The Kaplan-Meier 5- and 7-year survival rates for this patient cohort were 54% and 38%, respectively. In conclusion, a major renal insult requiring temporary RRT after cardiac surgery does not increase the risk for renal dialysis in the long term for patients with normal renal function preoperatively.