3D Modeling and Printing in Congenital Heart Surgery: Entering the Stage of Maturation

Abstract

3D printing allows the most realistic perception of the surgical anatomy of congenital heart diseases without the requirement of physical devices such as a computer screen or virtual headset. It is useful for surgical decision making and simulation, hands-on surgical training (HOST) and cardiovascular morphology teaching. 3D-printed models allow easy understanding of surgical morphology and preoperative surgical simulation. The most common indications for its clinical use include complex forms of double outlet right ventricle and transposition of the great arteries, anomalous systemic and pulmonary venous connections, and heterotaxy. Its utility in congenital heart surgery is indisputable, although it is hard to "scientifically" prove the impact of its use in surgery because of many confounding factors that contribute to the surgical outcome. 3D-printed models are valuable resources for morphology teaching. Educational models can be produced for almost all different variations of congenital heart diseases, and replicated in any number. HOST using 3D-printed models enables efficient education of surgeons in-training. Implementation of the HOST courses in congenital heart surgical training programs is not an option but an absolute necessity. In conclusion, 3D printing is entering the stage of maturation in its use for congenital heart surgery. It is now time for imagers and surgeons to find how to effectively utilize 3D printing and how to improve the quality of the products for improved patient outcomes and impact of education and training.

Keywords: 3D modeling; 3D printing; congenital heart surgery; education; hands-on surgical training; surgical simulation.

Figure 1

3D modeling of cast (left-hand panels) and endocardial surface anatomy (middle and right-hand panels) for double outlet right ventricle with a subpulmonary ventricular septal defect (VSD). A cast is modeled from CT images by signal intensity-based thresholding for contrast-enhanced blood pool. By hollowing the cast model toward outside, a negative of the cast is produced to replicate the endocardial surface anatomy. The endocardial surface represents true anatomy, while the outer surface does not. The sites of attachments of the cardiac valve leaflets are marked as ridges and the graphically designed leaflets and chords are added for reference. Ao, aorta; LAA, left atrial appendage; LAO, left anterior oblique; LV, left ventricle; OS, outlet septum; PT, pulmonary trunk; RV, right ventricle; SVC, superior vena cava.

Figure 2

3D-printed surgical simulation model for a patient with so-called Raghib syndrome (unroofed coronary sinus with persistent left superior vena cava). Left hand panels are frontal views of the 3D-reconstructed cast image (A) and endocardial surface image (B). Green dotted line shows the path of the left superior vena cava (LSVC) that connects to the roof of the left atrium (LA). Middle and right-hand panels show four surgical options practiced on the 3D-printed models. Option 1, graft interposition between right (RSVC) and LSVC. Option 2, direct anastomosis of disconnected LSVC to RSVC without graft. Option 3, intraatrial baffling of LSVC orifice to right atrium (RA) along the roof of the left atrium (LA). Option 4, intraatrial baffling of LSVC orifice to RA along the floor of the LA. The course of the baffle is marked with white dotted line. Option 3 was chosen for surgical treatment (29).

Figure 3

Models for patch repair of a ventricular sepal defect (D) with the hole well-exposed (A), with the graphically designed cardiac valve leaflets added (B) and with the graphically designed cardiac valve leaflets and chordae tendinae added (C).

Figure 4

Operating table-chest wall simulator assembly. The simulator is equipped with suture retention disk, surgical lighting and webcam video-recorder. The table can be raised and tilted.

Figure 5

Examples of surgical simulation models for atrioventricular septal defect repair (AVSD), arterial switch operation for transposition of the great arteries (TGA) and Norwood operation for hypoplastic left heart syndrome (HLHS). Only the endocardial surface anatomy is represented with a wall thickness of 0.9–1.2 mm.

Figure 6

A set of 3D-printed models used for explanation of transposition of the great arteries and arterial switch operation. Ao, aorta; LV, left ventricle; PT, pulmonary trunk; RA, right atrium; RV, right ventricle; SVC, superior vena cava.