3D printed models enhance understanding of complex anatomy in congenital heart disease. However few studies assessed the accuracy of measurements in printing model. Our aim was to assess the feasibility and accuracy of 3D printing in children with conotruncal ventricular septal defect (VSD).

This prospective study included patients with conotruncal VSD who underwent cardiac CT scan. VSD and aortic annulus diameters in two orthogonal axes were measured using Multiplanar Reformating (MPR) mode on CT images. CT DICOM files were imported to dedicated software (Mimics medical 19, Materialise, Belgium) for segmentation and to generate the 3D object. A hollow model was created using 3-Matic software (Materialise, Belgium) and cropped to better visualize the relationship between VSD and great arteries. VSD and aortic annulus diameters were measured on 3D models in two orthogonal axes and compared to measurements obtained from CT images (Fig. 1).

Fourteen patients were included (1 TA, 1 PA-VSD, 1 DOLV, 2 TOF, 9 DORV). Mean age 5.5 months (range 3 weeks–48 months), mean weight 6.7kg (range 3.5–16kg). 3D models were successfully obtained in all patients. Correlation between measurements obtained from 3D models with those obtained from source CT images was high (R=0.977). Mean measurements of VSD diameters from CT images and 3D models were 8.5mm and 8.1 respectively (P=NS). Mean measurements of aortic annulus diameters from CT images and 3D models were 15.8mm and 14.9mm respectively (P=NS), indicating the absence of any significant difference.

3D printing is feasible in pediatric population with complex congenital heart disease and demonstrates correctly the spatial relationship between VSD and great arteries. Structure measurements are not significantly different between 3D model and source CT images.