Perioperative risk of aortic valve replacement after coronary artery bypass grafting

Objective: To evaluate the operative risk of aortic valve replacement (AVR) after coronary artery bypass grafting (CABG). Methods: Twenty patients (sixteen male, four female) underwent AVR 1.5 - 20 years (mean: 8.2) after CABG. Results: Patients had received a mean number of four bypass grafts (2 - 5) with the use of the left internal thoracic artery in seventeen patients. Mean age at the time of AVR was 70.5 years (57 - 82). All patients suffered from an aortic stenosis with a mean orifice area of 0.74 cm(2) (0.34 - 1.1) and a mean pressure gradient of 52.4 mm Hg (22 - 78). Ten mechanical (mean diameter 23.6 mm, 21 - 27) and ten biological (22.1 mm, 19-25) prostheses were implanted. Mean duration of surgery, cardiopulmonary bypass (CPB) and cross-clamp time were 322.1 (205-645), 169.2 (87 - 411), and 77.1 (46 - 128) minutes, respectively. Fourteen patients had an uneventful postoperative course. A temporary neurological impairment, renal failure, and re-intubation for respiratory insufficiency for nine hours occurred in one patient each. Two patients died postoperatively (day 3 and 10) due to multiple cerebral infarctions. One patient required a replacement of the ascending aorta in deep hypothermia and re-implantation of the bypasses. He suffered from gastrointestinal bleeding on postoperative day 14 and expired on day 81 because of multi-organ failure. Conclusion: Aortic valve replacement after coronary artery bypass grafting is associated with an enhanced perioperative risk requiring meticulous decision-making and a sophisticated operative technique.