High Thoracic Tortuosity Is Associated With CT-Markers of Degeneration of the Descending Thoracic Aortic Wall

Increased vascular tortuosity may be an independent marker of generalized aortic pathology. This study investigates the association between descending thoracic aortic tortuosity, aneurysm pathophysiology, and outcomes following EVAR in AAA patients. Patients who underwent elective EVAR between 2004 and 2018 were reviewed. Thoracic tortuosity index (TTI) was measured using 3D reconstruction software. Patients were dichotomized across the median TTI into high tortuosity [HT] (TTI >1.27, Figure1(a) ) and low tortuosity [LT] (TTI ≤1.27, Figure 1(b) ) groups. Perioperative complications, postoperative outcomes, and CT-based features of thoracic aortic wall degeneration ( Figure 1(c)-(e) ) were collected and analyzed. 136 patients underwent treatment: 70 HT patients, including 54 males and 16 females (mean age: 77 years), and 66 LT patients, including 62 males and 4 females (mean age: 70 years) (age; P < .001). LT patients exhibited greater prevalence of hypercholesterolemia and diabetes (P = .045, P = .01). Presence of degenerative aortic wall markers was greater in HT patients (P = .045). HT patients had higher incidence of multiple aneurysms concurrently present in their aorta compared to LT (32.8% vs 11.3%; P = .002). Frequency of AAA rupture/dissection was 4.3% for HT and 1.5% for LT (P = .339). A trend was observed in all cause 30-day mortality in the HT group (P = .061). Other perioperative complications and postoperative outcomes were similar between groups. High TTI was associated with older age at time of EVAR, greater prevalence of degenerative markers in the descending thoracic aortic wall, and widespread aorto-iliac dilation. While not predictive of EVAR outcomes, TTI can provide valuable information regarding aneurysm pathophysiology.