Remodeling of abdominal aortic branch perfusion after thoracic endovascular aortic repair for aortic dissections.

Objective: The fate of the abdominal aorta and its branches after thoracic endovascular aortic repair for aortic dissection (TEVAR-AD) has not been studied. The objective of this study was to describe the midterm changes in abdominal aortic branch perfusion after TEVAR-AD.

Methods: A retrospective analysis of TEVAR-AD at a single institution from December 1, 2008, to March 31, 2015, was performed. Computed tomography angiography (CTA) images were reviewed to characterize the perfusion pattern changes of the celiac, superior mesenteric, inferior mesenteric, bilateral renal, and common iliac arteries. Risk factors associated with branch interventions were identified.

Results: During the study period, 68 patients underwent TEVAR-AD, 46 of whom had pre-TEVAR and post-TEVAR CTA images available for review. For post-TEVAR CTA, the most recent scans were selected for analysis. The mean period between CTA studies was 371 days. Indications for TEVAR-AD were persistent pain (41%), malperfusion (15%), rupture (6%), and aneurysmal degeneration (33%). Twenty-five patients (54%) were treated during the acute phase (<14 days). All patients had dissections extending to the paravisceral aorta. Of the 304 abdominal aortic branches analyzed, 8 required intervention (2.6%). Branch events requiring intervention included malperfusion (two) and aneurysms involving the branches (three). No intervention was performed for one asymptomatic inferior mesenteric artery occlusion. Of the remaining 295 branches, changes in perfusion patterns were observed in 16 (5.4%). Twelve branches (75%) demonstrated an increased true lumen contribution to perfusion. Four branches (25%) had increased false lumen contribution, without clinical evidence of malperfusion. Patients requiring branch interventions were more likely to have severe chronic kidney disease (P = .012) and more extensive aortic zone coverage during TEVAR (P = .003). On multivariable Cox proportional hazards analysis, coverage of four or more zones during TEVAR-AD was associated with branch intervention (odds ratio, 6.44; 95% confidence interval, 1.01-40.8). The estimated intervention-free patency of the abdominal aortic branches was 89% at 5 years.

Conclusions: Perfusion patterns of abdominal aortic branches remain largely stable after TEVAR-AD. The need for branch intervention is rare and associated with extensive aortic coverage.