Advantages of 3D printed ASD models based on 3D-TEE images
The clinical diagnosis and treatment of Atrial septal defect (ASD) mainly depends on echocardiography images. But the 2D images often lack of pivotal spatial information and fully measurable morphological parameters, higher requirements are raised for the cardiologists and cardiovascular surgeons to a mental conversion of 2D data into a 3D understanding of the spatial relationships of intracardiac structures9. Although 3D images can show the morphology of ASD more comprehensive, in patients with complex types such as ASD with atrial septal aneurysm (ASA), ASD with multi holes, ASD of inferior vena cava type and ASD with rim deficiency, 3D-TEE has been less beneficial for the intuitive and accurate surgical operation plan. The emerging 3D printing technology is a process that a solid, patient specific physical 3D model is created through layer-by-layer superposition molding from rendered computer-generated images, which makes it possible to create patient-specific 3D models based on imaging data15. These tangible models of patient anatomy have demonstrated value in education, simulation, and surgical planning16. 3D printed ASD models can not only provides a more intuitive 3D perspective, comprehensively shows the morphological structure of the lesion to improves the diagnostic accuracy, but also provides haptic feel, enabling the surgeon to a more realistically understanding for the deformation of the surgical area produced by external pressure during the operation and help plan the surgical approach to enhance the success rate of the treatment17,18. The size and shape of ASD can be observed intuitively, and the simulated interventional treatment can be performed on the model, which may provide more information for the therapy.
Compared with CT, which is the most commonly used medical imaging modalities for 3D image generation, echocardiography has a superior ability to image fast moving structures such as cardiac valves and intracardiac defect and directly display the area of interest and intracardiac defects with high image resolution6. Moreover, 3D-TEE is an important imaging method that plays a critical role in the process of preoperative diagnosis, intraoperative monitoring and postoperative efficacy evaluation of ASD. Using 3D-TEE images as the data source of 3D printed ASD models can combine the advantages of echocardiography and 3D printing technology effectively.