Abstract 10570: A New Method for Planning the Surgical Repair of Pediatric Aortic Coarctation: In vitro Design and Performance Evaluation

Abstract

Introduction: The surgical treatment of severe aortic coarctation associated with arch hypoplasia combines resection of the stenosed tissue and enlargement of the aortic arch with a patch, designed by the surgeon in the OR. This work aims at creating an a priori design method for the patch and evaluating the success of the treatment by measuring the restoration of flow. Methods: Treatment was virtually implemented on segmented patient’s CT images based on the surgeons’ experience, identifying the zone to resect and the start of the lumen-widening, and optimized through CFD simulations The optimal patch geometry template was 3D-printed and used to perform surgery on in vitro silicon models of the aorta. Repairs were performed by an experienced surgeon using two patch geometries: the optimal patch template designed by our methodology and the patch designed by experience (traditional method). The geometry of the lumen resulting from the surgery was obtained from micro-CTs of the models. Finally, CFD simulations were performed for these geometries to evaluate the two repairs. Results: All repairs showed significant increases in aortic flowrate and decreases in pressure gradient. The virtually repaired geometry resulted in a 3-fold increase in flowrate and complete resolution of the obstruction. The traditional repair and the optimal patch repair showed similar effects on flow rate (+300%), and the traditional repair showed no remaining pressure gradient. All repairs reduced the stenosis-induced jet. However, the traditional repair led to large recirculation zones, potentially increasing the risk of thrombosis and pathological aortic remodeling. Conclusion: A novel method, combining in vitro and in silico approaches, was created to help surgical planning. This approach predicted flow and pressure gradients for the evaluation of the repair, but also provided the flow topology that should be taken into consideration to avoid hemodynamics-related complications.