A hemodynamic analysis of fenestrated physician-modified endograft repair for complicated aortic dissections involving the visceral arteries.

Objective: The aim of this study is to perform patient-specific hemodynamic simulations of the patients with complicated aortic dissection underwent Physician-modified endograft (PMEG) and evaluate the treatment outcome.

Method: 12 patient-specific models were reconstructed from computed tomography angiography (CTA) data of 6 patients with complicated aortic dissection before and after the PMEG. Hemodynamic simulations were conducted with the same time-varying volumetric flow rate extracted from the literature and 3-element Windkessel model (3 EWM) boundary conditions were applied at the aortic outlet. Hemodynamic indicators such as time-averaged wall shear stress (TAWSS), relative residence time (RRT) and endothelial cell activation potential (ECAP) were obtained to evaluate the postoperative effect of PMEG.

Results: Comparing with the preoperative models, the flow rates of most visceral arteries were increased in the postoperative models (P = 0.012, P = 0.013, and P = 0.005). Pressure and TAWSS in visceral regions were significantly reduced (P = 0.003 and P = 0.017). With the false lumens (FL) covered by the stent grafts, the average TAWSS level increased in the regions of postoperative abdominal aorta (P = 0.002), and the average RRT and ECAP values decreased significantly (P = 0.02 and P = 0.003).

Conclusion: This study shows that PMEG, as a new technique for the treatment of complicated aortic dissection involving the distal tears in the visceral region, can effectively restore the abnormal blood supply of the visceral arteries, reduce the risk of aortic rupture, the formation of aortic dissection aneurysm (ADA), and thrombosis. This corresponds well with clinical retrospective studies and 1-year follow-up outcomes. The findings of this study are of great significance for the development of PMEG.