Abstract 15923: A Combined In Silico and In Vitro Approach for Surgical Planning of Pediatric Coarctation Repair

IntroductionCoarctation of the aorta is a congenital malformation of the proximal descending aorta that results in severe narrowing of the vessel lumen. It causes significant changes in the aortic hemodynamics, including reduced blood flow and an increased pressure gradient in this area of the vasculature. When this congenital cardiac malformation is associated with aortic arch hypoplasia, a two step-surgery is proposedfirst, an end-to-end anastomosis in performed to remove all the ductal tissue surrounding the coarctation, and then the aorta is longitudinally incised and patched to increase its diameter. The design of the patch, based on the surgeon’s experience, is done in the OR. A combined in silico and in vitro approach is proposed to test the possibility of a priori design of the patch. This approach would also open the door to optimization of the patch to restore physiological hemodynamics in the aorta. Methods & ResultsCFD simulations of the hemodynamics in the pre-treatment aortic arch were created from the segmentation of patients’ images who received surgical treatment at Seattle Children’s Hospital. In vivo hemodynamics data were used as boundary conditions for the simulation. The design of the patch was created via an in-house code and was based on surgeons’ inputthe locations of the start and the end of the lumen enlargement and the length of the aortic segment to be resected. The optimization of the patch design was performed by comparing the simulated hemodynamics (pressure drop, endothelial shear stress, size of the recirculation region, ...) before and after the patch repair. The optimized patch design was then used by the surgeon to perform the in vitro surgical treatment on a physical model of the patient’s anatomy, made in a translucent silicon rubber. The repaired anatomical model was scanned by X-ray microtomography and cast in an optically clear silicone. Time-resolved particle image velocimetry measurements were performed to characterize the post-treatment hemodynamics, and compared to the results of the CFD simulation. ConclusionsThis unique in silico and in vitro approach allows surgeons to perform different repairs on patient-specific physical in vitro models and to optimize the design of the patch prior to starting the surgery.