Abstract Body (Do not enter title and authors here): Introduction: Uncomplicated Stanford type B acute aortic dissection is traditionally managed with strict blood pressure control. However, many patients who survive the acute phase develop dissecting aortic aneurysms owing to false lumen expansion in the chronic phase.
Objectives: This study investigated treatment strategies for Stanford type B aortic dissection, specifically comparing the outcomes of full provisional extension to induce complete attachment (PETTICOAT) thoracic endovascular aortic repair (TEVAR) with those of simple entry closure using TEVAR. This study aimed to elucidate the long-term results of full PETTICOAT TEVAR and the mechanisms underlying false lumen expansion or suppression through computational fluid dynamics analysis.
Methods: This retrospective study included 22 patients diagnosed with Stanford type B aortic dissection: 12 in the full PETTICOAT group and 10 in the entry closure group. Computed tomography images were analyzed at various time points till four years postoperatively by measuring the aortic, true lumen, and false lumen diameters at four levels. Statistical analyses were performed using Welch's t-test, and statistical significance was defined as p < 0.05. Additionally, blood flow analysis was performed for one case from each group. We aimed to approximate solutions from the fluid equations, visualize blood flow, and compare hemodynamic parameters, namely wall shear stress and oscillatory shear index.
Results: In the fourth postoperative year, there was a significant difference in aortic diameter (p = 0.012) and false lumen diameter (p = 0.001) at level 3 (diaphragm level of the descending aorta), and the full PETTICOAT group showed smaller values indicative of favorable remodeling. Blood flow analysis revealed elevated oscillatory shear index values in the false lumens of the entry closure group, suggesting a correlation with false lumen expansion.
Conclusions: Full PETTICOAT TEVAR demonstrated positive long-term outcomes by reducing the false lumen and preventing aortic enlargement. This study provides insights into the underlying hemodynamic mechanisms, emphasizing the potential of computational fluid dynamics analysis in understanding aortic dissection treatment strategies.