Preoperative thoracic false lumen branches relate to aortic remodeling after thoracic endovascular aortic repair for DeBakey IIIb aortic dissection

Objective

This study evaluated the association between thoracic false lumen branches (TFLBs; dissected thoracic branches fed by a false lumen) and distal thoracic aortic enlargement (DTAE) after thoracic endovascular aortic repair (TEVAR) for DeBakey IIIb aortic dissection.

Methods

We retrospectively analyzed the records of 67 patients with DeBakey IIIb dissection initially treated with TEVAR between January 2011 and December 2013. Preoperative and postoperative computed tomography angiography images were reviewed to evaluate the number of preoperative TFLBs and aortic diameter change after TEVAR. Patients were stratified into two groups by the estimated optimal cutoff value of preoperative TFLBs for the prediction of DTAE: group A (n = 28), preoperative TFLBs ≥8; group B (n = 39), preoperative TFLBs <8. The diameter changes over time were modeled by mixed models of repeated data. Multivariable Cox regression analysis was used to assess the independent association between preoperative TFLBs and DTAE after TEVAR.

Results

Baseline demographics, clinical features, and devices implanted were largely similar between the two groups. Group A had more preoperative abdominal false lumen branches (7 [4-8] vs 4 [1-6]; P = .02) and a greater proportion of preoperative patent thoracic false lumen (83.9% vs 66.7%; P = .04). Twelve patients experienced DTAE during a median imaging follow-up period of 12.2 months (interquartile range, 4.3-26.6 months). Log-rank testing revealed a significant increase in cumulative estimated proportion with DTAE in group A (P < .01). The maximum thoracic aortic diameter decreased significantly in group B (P < .01) but not in group A. The overall change in the maximum thoracic aortic diameter was statistically different between the two groups (P < .01). Each group exhibited a significant increase in true lumen diameter and a significant decrease in false lumen diameter postoperatively. However, a lower degree of false lumen regression in group A was detected compared with group B (P = .03). Multivariable analysis identified that preoperative TFLBs were independently associated with DTAE after TEVAR (hazard ratio [for one increase], 1.46; 95% confidence interval, 1.20-1.77) after adjustment for gender, hyperlipidemia, length of dissected aorta and height index, preoperative abdominal false lumen branches, and preoperative false lumen status of thoracic aorta.

Conclusions

Preoperative TFLBs are independently associated with DTAE after TEVAR in DeBakey IIIb aortic dissection. Long-term follow-up is necessary to further verify the preliminary finding.