Increased incidence of acute ascending aortic dissection with off-pump aortocoronary bypass surgery?

Background. An apparent increase in the incidence of acute ascending aortic dissection following off-pump coronary artery bypass grafting (OPCAB) led us to assess retrospectively the rate and circumstances of this complicatio n in our institution on a consecutive series of patients undergoing aortoco ronary bypass performed with and without extracorporeal circulation (ECC). Methods. A retrospective analysis of acute ascending aortic dissections com plicating coronary artery bypass grafting surgery in 3,031 patients in our institution since April 1, 1995, was performed using the database of the Mo ntreal Heart Institute. Results. There was a greater frequency of hypertension in the OPCAB group. Iatrogenic acute aortic dissection occurred in 3 patients among 308 operate d on without ECC (0.97%) and 1 patient among 2,723 operated on under ECC (0 .04%). This difference was statistically significant (p < 0.00001). Conclusions. The risk of aortic dissection may be increased in OPCAB. Caref ul manipulation of the aorta with a single side-clamping and a control of t he arterial pressure should be used to minimize aortic trauma. High-risk pa tients should undergo CABG without side-clamping of the aorta or CABG with ECC to prevent this redoubtable complication of myocardial revascularizatio n. (Ann Thorac Surg 2001;71:117-21) (C) 2001 by The Society of Thoracic Sur geons.