Hemodynamic analysis of physician-modified stent grafts in the treatment of distal residual dissection of type B aortic dissection

Background: There have been very few reports which specifically address the use of physician-modified stent grafts (PMEGs) to isolate and repair distal residual dissection of type B aortic dissection (TBAD). This study aimed to assess the usage of PMEGs in the treatment of distal residual dissection of TBAD by analyzing the relevant hemodynamical indicators. Methods: One patient with TBAD underwent thoracic endovascular aortic repair surgery in the first stage, and in the second stage PMEGs were used to repair the residual dissection. Computational fluid dynamics (CFD) and three-dimensional structural analyses were performed, based on computed tomography angiography (CTA) datasets. The prognostic post-implantation improvement was studied using both quantitative and qualitative functional analysis. Results: The true lumen of the patient was expanded significantly in the post-operation period. The vascular pressure of the patient was high and unevenly distributed before the operation. Significant reductions in the wall shear stress related parameters of the region around the PMEGs—namely, time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI)—were observed after the implantation of the stent. Quantitative analysis showed that, while the blood flow decreased in the celiac trunk artery, the blood flow in the superior mesenteric artery and bilateral renal arteries increased. Conclusions: In the short term, the results of PMEGs in the treatment of distal residual dissection of TBAD were encouraging. Further evaluation with CFD may lead to new insights into the efficacy of this treatment, and help to guide the further treatment of complex abdominal aortic lesions.