Thoracic aortic geometry correlates with endograft bird-beaking severity
Journal of Vascular Surgery
Objective: Aortic geometry has been shown to influence the development of endograft malapposition (bird-beaking) in thoracic endovascular aortic repair (TEVAR), but the extent of this relationship lacks clarity. The aim of this study was to develop a reproducible method of measuring bird-beak severity and to investigate preoperative geometry associated with bird-beaking. Methods: The study retrospectively analyzed 20 patients with thoracic aortic aneurysms or type B dissections treated with TEVAR. Computed tomography scans were used to construct three-dimensional geometric models of the preoperative and postoperative aorta and endograft. Postoperative bird-beaking was quantified with length, height, and angle; categorized into a bird-beak group (BBG; n = 10) and no bird-beak group (NBBG; n = 10) using bird-beak height ≥5 mm as a threshold; and correlated to preoperative metrics including aortic cross-sectional area, inner curvature, diameter, and inner curvature × diameter as well as graft diameter and oversizing at the proximal landing zone. Results: Aortic area (1002 ± 118 mm2 vs 834 ± 248 mm2), inner curvature (0.040 ± 0.014 mm−1 vs 0.031 ± 0.012 mm−1), and diameter (35.7 ± 2.1 mm vs 32.2 ± 4.9 mm) were not significantly different between BBG and NBBG; however, inner curvature × diameter was significantly higher in BBG (1.4 ± 0.5 vs 1.0 ± 0.3; P =.030). Inner curvature and curvature × diameter were significantly correlated with bird-beak height (R = 0.462, P =.041; R = 0.592, P =.006) and bird-beak angle (R = 0.680, P <.001; R = 0.712, P <.001). Conclusions: TEVAR bird-beak severity can be quantified and predicted with geometric modeling techniques, and the combination of high preoperative aortic inner curvature and diameter increases the risk for development of TEVAR bird-beaking.
Aortic arch, Bird beak configuration, Endograft, Endoleak, Thoracic endovascular aortic repair
Maxfield M. Frohlich, Ga Young Suh, Johan Bondesson, Matthew Leineweber, Jason T. Lee, Michael D. Dake, and Christopher P. Cheng. "Thoracic aortic geometry correlates with endograft bird-beaking severity" Journal of Vascular Surgery (2020): 1196-1205. https://doi.org/10.1016/j.jvs.2019.11.045