Simulation of Optimal Surgical Anastomosis of Pediatric Aortic Cannula

Ventricular assist devices (VADs) have received widespread application to treat adults with end-stage heart failure. However, application to the pediatric population has been limited due to the excessive size; and therefore miniature, pediatric VADs (PVADs) are now being developed for the pediatric population to expand the current treatment options available to young patients with congenital heart defects and acquired heart disease. These pumps are typically connected via the left ventricular apex (via an inflow cannula) to the ascending aorta (via an outflow cannula). The distal anastomosis between outflow cannula and aorta has been studied by other researchers [1, 2] revealing complex fluid dynamic phenomena due to the non-physiologic confluence of native blood flow and outflow from the VAD. The corresponding pediatric anastomosis differs in dimensions and proportions to the adult, and has not yet been studied. The objective of this initial study is to examine the influence of cannula design, location, angle of insertion, and flow rate on the macro- and micro-fluid dynamics in the pediatric aorta. This parametric study is intended to provide both developers and surgeons with insight that would lead to optimization of both the cannula and surgical procedure, with particular emphasis at avoiding recirculation and stagnation flows commonly associated with platelet activation and thrombus generation [2, 3].