Introduction: An aging society brings with it a wide range of medical problems, one of which is an increasing number of patients with a severely calcified aorta1. These patients, who often require thoracic aortic surgery, may encounter numerous obstacles during the surgery. For one, the calcified intima interferes with suturing of the aorta, thereby renders aortic anastomosis to be difficult. Moreover, should the calcified aorta be forcibly sutured, the aortic wall may split and lead to bleeding or rupture. In view of the increased risk of complications that would affect the surgical plan and outcome, it is important to predict the extent of aortic calcification preoperatively. Computed tomography (CT) is a useful device for diagnosis of calcified lesions, but no quantitative evaluation has been established to predict whether simple anastomosis or any additional manipulation such as endarterectomy is required during operation. Here, we conducted this retrospective study to establish the reference value range of the maximal CT value for application of simple anastomosis in thoracic aortic surgery.
Patients and Methods: Between 2007 and 2011, 122 consecutive patients (mean age = 67 ± 14 years) underwent replacement of the thoracic aorta were included in this study. Patients with acute aortic dissection were excluded, though those with chronic aortic dissection were included such as dissecting aortic aneurysm. We divided the 122 patients into 2 groups, 105 patients (mean age = 66 ± 14) underwent simple anastomosis (Simple group), and 17 patients (mean age = 73 ± 6) required endarterectomy before undergoing anastomosis (Manipulation group). Preoperative CT scans were taken and the maximal CT value at the anastomosis site in comparison with postoperative CT was calculated using a diagnostic imaging software (AZE Virtual Place Raijin, Aze Ltd., Tokyo, Japan), based on the peak Hounsfield unit (HU) of the detected calcified lesions. When it was less than 130 HU, we defined 0 HU at the area. The institutional review board approved this retrospective study. Informed consent was obtained from all patients.