Perioperative type I aortic dissection during conventional coronary artery bypass surgery: risk factors and management.

Objectives: Perioperative iatrogenic type I aortic dissection (PIAD) is a rare but potentially fatal complication of conventional coronary artery bypass surgery (CCABG). Prompt recognition and repair of PIAD may significantly improve outcomes.

Methods: We reviewed the hospital records of patients with PIAD occurring as a complication of CCABG at Siyami Ersek Thoracic and Cardiovascular Surgery Center from January 2001 through June 2007. During this period, 10,130 CCABG were performed and 21 patients (0.20%) with PIAD were identified. We compared variables for these 21 patients with 603 patients without PIAD (control group).

Results: PIAD occurred intraoperatively in 19 patients (90%) and during the early postoperative period (first 6 hours) in 2 patients (10%) who underwent CCABG. Dissections were noticed after removal of the aortic crossclamp in 11 patients, during aortic cannulation in 3 patients, and after removal of the partial-occlusion clamp in 5 patients. Patients with and without PIAD differed significantly in regard to sex (P = .05), history of hypertension (P = .001), and history of severe concomitant peripheral arterial disease (PAD) (P = .001). The diameter of the aorta was significantly wider in patients with PIAD. (3.83 +/- 0.9 vs 2.93 +/- 0.46 cm, P = .019). The occurrence of high cardiopulmonary bypass (CPB) pressure (>==120 mmHg) was significantly higher in the PIAD patients than the non-PIAD patients (28.6% vs 3.3%, P = .0001). Seven PIAD patients (33.3%) died preoperatively and 3 (14.2%) died postoperatively.

Conclusion: PIAD is frequently fatal. Risk factors for PIAD during or after CCABG include female sex, history of PAD and hypertension, increased aortic diameter, and high CPB pressure.