Patient Population & definitions
The ethics committees at Yokohama city University medical center approved the study (14 May 2020, B200400073). Because this was observational retrospective study, the need for informed consent was waived.
A patient flow chart was shown in Figure 1. Between September 2012 and September 2019, a total of 283 patients visited our institution with a diagnosis of ATAAD. We evaluated 202 ATAAD patients (56.4% male, median age 68 years, IQR 57-76 years) who underwent open aortic repair surgery for ATAAD in this period. A comparative study was conducted in two groups based on the presence or absence of postoperative stroke. All patients who were suspected of having neurological complications underwent brain computed tomography (CT) and/or magnetic resonance imaging (MRI). We consulted with a neurologist and made a definite diagnosis of cerebral infarction based on the results of CT or MRI. Patients with both imaging and neurological findings were diagnosed stroke. We retrospectively examined the preoperative background factors, CT findings, intraoperative factors, change in dissection of supra-aortic vessels before and after ATAAD repair, and the long-term results of all patients. Supra-aortic vessels were divided into three groups: (1) no dissection, (2) dissection without severe stenosis of true lumen, (3) dissection with severe stenosis of true lumen. The stenosis rate of supra-aortic vessels was measured using the ECST method (European Carotid Surgery Trial) using preoperative CT images. A stenosis rate of 75% or higher was diagnosed as severe stenosis.