Impact of post-implantation syndrome on outcomes in acute type B aortic syndrome patients undergoing endovascular repair.

Background: The aim of this study was to explore the impact of post-implantation syndrome (PIS) on prognosis outcomes in individuals with type B acute aortic syndrome (AAS) undergoing thoracic endovascular aortic repair (TEVAR). Patients and methods: Data from type B AAS individuals who underwent TEVAR from January 2014 to April 2021 were retrospectively reviewed. Study subjects were divided into PIS and non-PIS (nPIS) groups and postoperative clinical outcomes were analyzed. Results: Our study cohort of 74 individuals with type B AAS included 40 aortic dissection (AD), 30 intramural hematoma (IMH), 4 penetrating aortic ulcer (PAU). The incidence of PIS was 14.9%. No statistically significant differences were found in baseline characteristics. The left subclavian artery (LSCA) reconstruction was performed more frequently among the PIS group (45.5% vs 9.5%, p=.008). Major adverse events (MAE) tended to be more frequent in the PIS group, but the difference was not significant (27.3% vs 22.2%, p=.707). At 2-year follow-up, results were comparable between the two groups. Kaplan-Meier analysis showed that PIS was not associated with a higher incidence of mortality, endoleak, new-onset AD, or stroke. A baseline neutrophil-to-lymphocyte ratio (NLR) >10.3 was associated with greater incidence of MAE. In individuals with IMH, better aortic remodeling evaluated by lower total aortic diameter/true lumen diameter (TAD/TLD) was achieved in the nPIS group (1.23±0.10 vs 1.43±0.07, p<.001), and a TAD/TLD ratio >1.32 was associated with significantly more MAE. Cox multivariate regression analysis also showed that a postoperative TAD/TLD ratio >1.32 was an independent risk factor for MAE (OR, 11.36; 95% CI, 1.53-84.26; p=.017). Conclusions: PIS was associated with a trend toward a higher incidence of MAE after TEVAR. In individuals with IMH, a TAD/TLD ratio >1.32 was an independent predictor of postoperative MAE.