The effect of aneurysm diameter on perioperative outcomes following endovascular thoracoabdominal aortic aneurysm repair

Abstract

Background: Endovascular repair of large diameter infrarenal and complex abdominal aortic aneurysms has been associated with worse outcomes. Whether these associations also apply to thoracoabdominal aortic aneurysms (TAAAs) remains unclear. Methods: We identified all patients who underwent endovascular repair for intact TAAAs between July 2010 and July 2024 in the Vascular Quality Initiative. A TAAA was defined as having a proximal aneurysm extent between zones 2 and 6, with at least one renal or visceral artery treated. Locally estimated scatterplot smoothing curves were used to visualize the relationship between preoperative aneurysm diameter and perioperative mortality, which informed the sex-specific definition of large aneurysms. Aneurysm size was categorized based on maximum diameter as follows (females/males): large (>60 mm/>65 mm), small (<50 mm/<55 mm), and medium (50-60 mm/55-65 mm). Perioperative outcomes were assessed using logistic regression models, and 5-year mortality was evaluated using adjusted Kaplan-Meier methods and Cox regression. Both large and small aneurysms were compared with medium-sized aneurysms. Results: A total of 1309 patients were included; of these, 54% underwent repair for medium-sized aneurysms, 37% for large aneurysms, and 9.1% for small aneurysms. The median follow-up was 345 days. After adjustment, compared with medium-sized aneurysms, large aneurysms were associated with 31% higher odds of any perioperative complication (adjusted odds ratio, 1.31; 95% confidence interval, 1.00-1.72; P = .046) and nearly twice the hazard of 5-year mortality (adjusted hazard ratio, 1.94; 95% confidence interval, 1.43-2.62; P < .01). The odds of perioperative mortality and in-hospital reintervention were similar between medium-sized and large aneurysms. No significant differences in perioperative outcomes or 5-year mortality were observed between patients with small and medium-sized aneurysms. Conclusions: After endovascular repair for TAAAs, compared with medium-sized aneurysms, large aneurysms (>60 mm in females, >65 mm in males) were associated with higher odds of any complication and higher 5-year mortality. Patients with small aneurysms (<50 mm in females, <55 mm in males) demonstrated similar perioperative outcomes and 5-year mortality compared with those with medium-sized aneurysms. These findings highlight the need to optimize management strategies for patients with large TAAAs and emphasize the importance of improved screening programs to enable earlier detection.