Influence of Abdominal Aortic Calcification on the Distal Extent and Branch Blood Supply of Acute Aortic Dissection.

Background: This study aimed to investigate the influence of abdominal aortic calcification on the distal extent, blood supply, and mid-term outcomes of acute aortic dissection (AAD).

Methods: This single-centre retrospective study was conducted from August 2014 to May 2021. The aortic calcification index was used to evaluate abdominal aortic calcification. The standardized method provided by the Society for Vascular Surgery was used to evaluate the distal extent of AAD. Patients were divided into 3 groups as per the degree of calcification: no calcification (NC), low calcification (LC), and high calcification (HC).

Results: In a cohort of 723 patients, abdominal aortic calcification was present in 424 (58.6%) patients. The prevalence of coronary heart disease increased with the degree of calcification (NC versus LC versus HC: 8.4% vs. 9.5% vs. 19.3%, P < 0.001). The aortic calcification index of the distal extent at zone 9 was higher than that of the distal extent exceeding zone 9 (P = 0.001). The proportions of the NC, LC, and HC groups with distal extents exceeding zone 9 were 65.9% vs. 56.2% vs. 37.7%, P < 0.001. In a multivariate logistics analysis, the calcification grade was a protective factor of distal extents exceeding zone 9 (P < 0.001, odds ratio [OR] = 0.592). Hypertension (P = 0.019, OR = 1.559) and D-dimer (P < 0.001, OR = 1.045) were risk factors. There was a higher proportion of branch-vessels on the abdominal aorta supplied by the true lumen in the calcification group (NC versus LC versus HC: 27.8% vs. 43.8% vs. 51.1%, P < 0.001). There were no significant differences in the mid-term outcomes among the groups.

Conclusions: Abdominal aortic calcification could limit the distal extent in patients with AAD and increase the proportion of branch-vessels on the abdominal aorta supplied by the true lumen.