BACKGROUND: 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.
METHODS: The 15,144 consecutive patients who underwent cardiac surgery from 
April 1999 to April 2011 were studied retrospectively on data collected 
prospectively.
RESULTS: 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.
CONCLUSIONS: 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.