Iatrogenic intraoperative type A aortic dissection following cardiac surgery

Abstract

An increase in the incidence of intraoperative aortic dissection has been reported recently, attributed to the increasingly elderly patient population undergoing cardiac surgery and more off-pump coronary artery bypass. We performed this study to examine current trends, identify risk factors for iatrogenic dissection, and compare iatrogenic intraoperative aortic dissection with spontaneous aortic dissection. The 15,144 consecutive patients who underwent cardiac surgery from April 1999 to April 2011 were studied retrospectively on data collected prospectively. Iatrogenic type A aortic dissection following cardiac surgery was diagnosed intraoperatively in 7 (0.04%) patients. Of the 4784 patients who had off-pump coronary artery bypass, only 2 (0.04%) developed iatrogenic intraoperative aortic dissection. Patients in the iatrogenic aortic dissection group were older by a decade (median age 72 vs. 62 years, p = 0.01). The cannulation site in conventional coronary artery bypass grafting and injury by the side-biting clamp in off-pump coronary artery bypass were the most common causes of dissection. Atheromatous disease was identified at the site of cannulation in 5 (71.4%) of the 7 cases. Intraoperative aortic dissection remains a rare and unpredictable complication of cardiac surgery, with worse outcomes than spontaneous aortic dissection. Increased age and atheromatous disease at the site of cannulation are significant risk factors for iatrogenic dissection. In this series, off-pump coronary artery bypass did not appear to be a risk factor for iatrogenic aortic dissection.