Transcatheter Aortic Valve Replacement

Three dimensional (3D) stereolithographic printing can be used to convert clinical imaging data into life size, patient-specific physical models replicating the anatomic characteristics of calcific aortic valve disease. Creation of these full-scale models requires a combination of several technologies including high spatial resolution electrocardiogram-gated computed tomography, computer-aided design software, and fused multimaterial 3D printing. By selecting specific print material properties, it is possible to replicate the geometry of the entire aortic root complex combining regions of compliant tissue with regions of hard and immobile “calcified” tissue. 3D printing of calcific aortic valve disease has been taken another step forward in replicating not only the anatomy but also the basic functional characteristics of these valves: stenosis and regurgitation. These functional models allow for accurate evaluation of diseased patient-specific physiology and represent a potentially very powerful new tool. Development of functional patient-specific models has several potential applications in medicine: training of medical teams for transcatheter aortic valve replacement (TAVR) procedures; investigating the flow dependency of aortic stenosis or regurgitation using flow phantoms; determining the accuracy and limitations of noninvasive imaging methods to quantify valve dysfunction; and evaluating patient-specific procedural adjustments a priori that may influence acute procedural success during catheter-based valve intervention. Functional 3D-printed models and accurate replication of patient-specific hemodynamics can create an environment for testing percutaneous valve devices and optimization of their design. Current effort is focused on applying these models to both predict and prevent paravalvular regurgitation.