Three-dimensional printed models in congenital heart disease.

The purpose of this article is to discuss technical considerations and current applications of three-dimensional (3D) printing in congenital heart disease (CHD). CHD represent an attractive field for the application of 3D printed models, with consistent progress made in the past decade. Current 3D models are able to reproduce complex cardiac and extra-cardiac anatomy including small details with very limited range of errors (<1 mm), so this tool could be of value in the planning of surgical or percutaneous treatments for selected cases of CHD. However, the steps involved in the building of 3D models, consisting of image acquisition and selection, segmentation, and printing are highly operator dependent. Current 3D models may be rigid or flexible, but unable to reproduce the physiologic variations during the cardiac cycle. Furthermore, high costs and long average segmentation and printing times (18-24 h) limit a more extensive use. There is a need for better standardization of the procedure employed for collection of the images, the segmentation methods and processes, the phase of cardiac cycle used, and in the materials employed for printing. More studies are necessary to evaluate the diagnostic accuracy and cost-effectiveness of 3D printed models in congenital cardiac care.