An observational assessment of aortic deformation during infrarenal and complex endovascular aortic aneurysm repair

Objective: Real-time aortic deformation during endovascular aortic aneurysm repair (EVAR) has not been reported. Successful EVAR relies on predicting intraoperative aortic-endograft deformation from preoperative imaging. Correct prediction is essential, because malalignment of endografts decreases patient survival. We describe intraoperative aortic deformation during infrarenal EVAR and complex fenestrated/branched EVAR (F/BEVAR), relating deformation to preoperative anatomy and follow-up outcomes. Methods: A multicenter, retrospective cohort of aortic aneurysm patients undergoing operation between January 2019 and February 2021, substratified by repair, infrarenal EVAR (n = 50), F/BEVAR (n = 80), and iliac branch graft with F/B/EVAR (IBG + F/B/EVAR; n = 27), were compared using software-based nonrigid two- and three-dimensional aortic deformational intraoperative assessment (CYDAR). Preoperative computed tomography reconstructions of aortic and iliac tortuosities were assessed against intraoperative deformation, the primary outcome, and related to perioperative and follow-up adverse outcomes. Results: All treatment groups had low preoperative visceral aortic tortuosity; the EVAR group had higher iliac tortuosity (1.43 +/- 0.05; P = .018). Intraoperative aortic visceral deformation was consistently cranial and anterior; IBG + F/B/EVAR patients had the largest magnitude deformation (superior mesenteric artery, EVAR 5.1 +/- 0.9 mm; F/BEVAR 4.4 +/- 0.4 mm; IBG 8.3 +/- 1.2 mm; P = .004). Celiac artery, superior mesenteric artery, and bilateral renal artery deformations were correlated (R = 0.923-0.983). Iliac deformation was variable in magnitude and direction. Preoperative tortuosity was not correlated with the magnitude of intraoperative deformation nor was deformation magnitude related to endograft instability during follow-up, including endoleak development, reinterventions, or visceral vessel complications. Conclusions: The aorta deforms consistently during EVAR at the visceral aortic segment but unpredictably at the iliac bifurcation. Aortoiliac deformation is unrelated to adverse perioperative outcomes, branch instability, or reinterventions during short-term follow-up.