Geometric Alterations Of Proximal Aorta After Endovascular Repair For Acute Type B Aortic Dissection

Objective:Thoracic Endovascular Aortic Repair(TEVAR)has become the most commonly used treatment for thoracic aortic disease.The remodeling of the aorta after TEVAR has been the focus of attention,but the evolution of the proximal aorta after TEVAR involving the "zone 2" aorta(between the left common carotid artery and the left subclavian artery)remains unclear.The objective of our current study was to evaluate early remodeling of the proximal aorta in patients with acute type B aortic dissection(ATBAD)by observing the geometric alterations of the proximal aorta after TEVAR with zone 2 aorta as the landing zone.Methods:Clinical data of 53 patients with acute type B aortic dissection in the Department of Cardiovascular Surgery of Shandong University Qilu Hospital from January 2016 to May 2022 were collected according to inclusion and exclusion criteria.All of them underwent zone 2 TEVAR due to unfavorable proximal landing zone.According to the the type of stent-graft implanted during the operation,they were divided into two groups,the single-branched stent-graft group(n=26),the common stent-graft group(n=27).Demographic characteristics,surgical details,postoperative complications and follow-up results were analyzed.Three-dimensional imaging created by computed tomography angiography was used to measure different parameters of the aorta,such as angulation,cross-sectional area(CSA),length and tortuosity.Comparing the geometric parameters of the proximal aorta before and 3 months after zone 2 TEVAR.Results:From the perspective of intra-group comparison,the postoperative angle of aortic arch to ascending aorta,descending aorta increased in all patients compared with that before surgery(all P<0.05),while the angle of aortic arch to left subclavian artery increased after surgery only in single-branched stent-graft group(P<0.001);As for CSA,the CSA of distal aortic arch and true lumen of descending thoracic aorta increased(all P<0.05),while the CSA of false lumen of descending thoracic aorta decreased in both groups after operation(all P<0.05);Only in single-branched stent-graft group,the CSA of the ascending aorta,proximal aortic arch and total descending thoracic aorta decreased after surgery(all P<0.05);In terms of length,the aortic arch prolonged after operation in both groups(P=0.018 and P=0.004,respectively).In addition,the ascending aorta tortuosity decreased in single-branched stent-graft group after surgery(P=0.011).There was no significant difference in the alterations of other aortic parameters after operation(P>0.05).From the perspective of inter-group comparison,there was a difference in false lumen remodeling between the two groups.Compared with the common stent-graft group,the single-branched stent-graft group had a more significant reduction in false lumen CSA after surgery(P=0.020).During the 3-month follow-up,the single-branched stent-graft group was superior to the common stent group in terms of postoperative endoleak rate and false lumen thrombosis(P=0.023 and P=0.001,respectively).Conclusions:For ATBAD patients with unfavorable proximal landing zone,zone 2 TEVAR has certain early remodeling effect on the proximal aorta.Compared with the zone 2 TEVAR implanted with common stent-graft,single-branched stent-graft implantation has a lower postoperative endoleak rate and better early remodeling of the false lumen.