Aortic Remodeling After Thoracic Endovascular Aortic Repair And Reintervention In Patients With Type B Aortic Dissection

Objective: The purpose of this study was to explore the aortic remodeling after thoracic endovascular aortic repair(TEVAR)and reintervention in patients with type B aortic dissection(TBAD).Methods: Firstly,a total of 135 patients with TBAD who underwent initial TEVAR in the hyperacute phase(within 24 hours of onset)and acute phase(1 to 14 days of onset)were retrospectively enrolled,including 32 patients with hyperacute TBAD and 103 with acute TBAD.The change in the aortic diameter and the degree of false lumen thrombosis in the two groups were analyzed and compared.Secondly,a total of 126 patients who had residual distal tears after initial TEVAR for TBAD were retrospectively included.The influences of the distribution of residual distal tears on the aortic remodeling of the distal segment were investigated.Logistic regression was performed to identify risk factors associated with adverse aortic remodeling of the distal segment.And lastly,a total of 24 patients with TBAD who received reintervention due to the residual distal tears after initial TEVAR were retrospectively studied.The changes in the aortic diameter and the length of the completely thrombosed false lumen were analyzed.Results: In the first part,the results showed that the stented segment increased significantly in diameter of the true lumen at all levels,decreased significantly in diameter of the false lumen at all levels,and decreased significantly in the total aortic diameter at the maximum level after TEVAR in the overall TBAD cohort(all P< 0.05).Patients with hyperacute TBAD had a more significant decrease in the total aortic diameter at both the level of 2 cm distal to the left subclavian artery and the maximum level of the stented segment than those with acute TBAD after TEVAR(all P< 0.05).Moreover,patients with hyperacute TBAD had a more significant decrease in the diameter of the false lumen at the maximum level of the stented segment than those with acute TBAD after TEVAR(P= 0.047).In addition,the rate of complete false lumen thrombosis of the stented segment was higher in hyperacute TBAD than that in acute TBAD after TEVAR(P= 0.036).Results from this part also suggested that the distal descending thoracic aorta increased significantly in diameter of the true lumen at all levels,decreased significantly in diameter of the false lumen at the maximum level,and increased significantly in the total aortic diameter at all levels after TEVAR in the overall TBAD cohort(all P< 0.05).Moreover,data presented that the abdominal aorta increased significantly in diameter of the true lumen at all levels except the level of aortic bifurcation,in diameter of the false lumen at all levels,and in the total aortic diameter at all levels after TEVAR in the overall TBAD cohort(all P< 0.001).In addition,the perioperative incidence of acute kidney injury was higher in hyperacute TBAD than that in acute TBAD(P= 0.029).In the second part,logistic regression analysis demonstrated that the distribution of the first residual distal tear and the location of the primary tear were independently associated with adverse aortic remodeling of the distal segment.When the first residual distal tear was located in the distal descending thoracic aorta after TEVAR in patients with TBAD,there was a significantly increased risk of adverse aortic remodeling of the distal segment compared with when it was located in the infrarenal abdominal aorta and iliac artery(odds ratio= 14.663,95% confidence interval: 1.672-128.606,P= 0.015).For the last part,the results showed that the timing of reintervention for each patient was at least 3 months after the initial TEVAR.The diameter of the true lumen increased and the diameter of the false lumen decreased at the lower edge of the renal artery after reintervention,with statistical significance(all P= 0.001).Furthermore,the diameter of the true lumen increased at the level of aortic bifurcation after reintervention,with statistical significance as well(P= 0.010).In addition,the lengths of the completely thrombosed false lumen of the descending thoracic aorta and the abdominal aorta increased after reintervention(all P< 0.05).Conclusions: The aortic remodeling in the stented segment was favorable after TEVAR in patients with hyperacute and acute TBAD,but not ideal in the distal segment.Moreover,aortic remodeling in the stented segment was more remarkable after TEVAR in patients with hyperacute TBAD than that in patients with acute TBAD,but a significant advantage was not shown in the distal segment.In addition,the perioperative risk of acute kidney injury was higher in patients with hyperacute TBAD than that in patients with acute TBAD.According to the clinical and anatomic conditions of the patients,TEVAR may be considered to be selectively performed in patients with hyperacute TBAD for more favorable aortic remodeling.Furthermore,patients with TBAD whose first residual distal tear was located in the distal descending thoracic aorta after TEVAR had a significantly increased risk of adverse aortic remodeling of the distal segment.The residual distal tears in the distal descending thoracic aorta after TEVAR should be actively and preemptively treated to improve the aortic remodeling of the distal segment.In addition,patients with TBAD may still benefit from the selective intervention of the residual distal tears in the chronic phase after initial TEVAR which could improve the aortic remodeling.