Aortic dissection with potential origin from a mechanical bypass anastomosis.

Ascending aortic dissection is a known complication of cardiac surgery. Off-pump coronary artery bypass surgery seems to be associated with a higher risk for this event as compared with on-pump bypass surgery. This increased risk may result from aortic side-clamping under pulsatile flow as opposed to continuous flow in conventional bypass surgery. Mechanical devices allowing performance of proximal bypass anastomoses without aortic side-clamping are supposed to reduce the risk for aortic dissection. We report a case in which ascending aortic dissection occurred 8 days after off-pump bypass surgery, most likely arising from a mechanically performed proximal bypass anastomosis.