Hemodynamic Consequences of Renal Artery Ostium Positioning After Inner-Branch Endografting for Juxtarenal Aortic...

To investigate the hemodynamic consequences of renal artery ostium positioning following endovascular repair of juxtarenal abdominal aortic aneurysms (JAAAs) using the novel WeFlow-JAAA inner-branch system.

Patient-specific computational fluid dynamics analysis was performed on 3 postoperative JAAA cases treated with the WeFlow-JAAA endograft. For each case, 4 models systematically simulated progressive distal migration of the bilateral renal ostia, ranging from a proximal position near the celiac artery to their native anatomical locations. Renal perfusion rates, aortic flow patterns, and established wall shear stress (WSS)-derived metrics (time-averaged wall shear stress [TAWSS], oscillatory shear index [OSI], relative residence time [RRT]) were quantitatively evaluated.

Distal renal ostium positioning consistently yielded higher renal perfusion rates compared to proximal placements. However, this improved perfusion was associated with the development of potentially adverse hemodynamic conditions (characterized by low TAWSS and high OSI/RRT) on the perirenal aortic wall adjacent to the ostia. Conversely, proximal placements, while mitigating these adverse perirenal WSS patterns, compromised renal perfusion and generated pronounced flow disturbances in the infrarenal aorta distal to the termination of the inner-branch parallel segments.

The preliminary findings suggest that renal ostium positioning after WeFlow-JAAA implantation may critically influence postoperative hemodynamics. The simulations indicate maximizing renal perfusion via distal placement may potentially expose the perirenal aortic wall to less favorable long-term WSS conditions. These results underscore the need for careful and potentially patient-specific consideration of device placement to appropriately balance perfusion and aortic wall remodeling risks in juxtarenal endovascular repair.