Proceedings of The Physiological Society

Physiology 2015 (Cardiff, UK) (2015) Proc Physiol Soc 34, PC161

Poster Communications

The use of colour-coded three dimensional printed models of a congenital heart defect to assist surgical planning for heart transplantation

M. L. Smith1, L. Nolke2, M. K. O'Reilly3, J. Murray3, J. F. Jones1

1. Division of Anatomy, University College Dublin, Dublin 4, Ireland. 2. Cardiothoracic Surgery, Mater Misericordiae University Hospital, Dubin, Ireland. 3. Department of Radiology, Mater Misericordiae University Hospital, Dubin, Ireland.

  • Posterior view of heart model

Purpose - We created a 3D printed colour-coded model of a complex CHD to aid visualisation of the aberrant anatomy to enhance surgical planning for transplantation for end stage heart failure. The anatomy was of a 41-year old patient with right atrial isomerism, dextrocardia, left inferior and superior vena cava to a single atrium, single ventricle with right ventricular morphology, double outlet right ventricle with transposition of the great vessels and total anomalous pulmonary venous drainage to the superior vena cava. Introduction - In the past decade, 3D printing has demonstrated a role in medical research and pre-operative planning. Studies have shown that patient-specific models of CHDs are a valuable aid to surgical planning (Ejaz et al., 2014). Due to the wide variation and complexity associated with CHDs, 3D visualisation of the aberrant structures based on the 2D images can prove challenging. Methods - Imaging: The data were obtained using a Somaton Definition AS+ 128 slice scanner. A cardiac gated contrast enhanced Commuted Tomography study was performed at 120kV with automatic mAs modulation. Images were acquired in 0.6mm slices and reconstructed using a Siemens Syngo system. The image matrix size was 512 x 512. All data were anonymised in keeping with local ethical guidance. Segmentation: A medical expert proficient in segmentation in conjunction with a Consultant cardiac Radiologist performed image analysis. Using open source 3D Slicer software, the structures of interest were segmented. The segmented images represented the bounding lumen of the heart and Great vessels. The generated 3D model was then exported as a stereolithographic (STL) file and further model optimisation was performed using Meshlab. Processing: Z Edit Pro was used for mesh editing and to attribute colours to the structures. The design process took 8 hours with 1 hour for attributing colours. This was then printed using a Z Print 250 binder jetting printer in 6 hours and 5 minutes. Post processing involved oven curing to improve model strength before an epoxy infusion system was applied to allow intensive model manipulation without fear of breakage. Results - We produced a colour-coded patient-specific model which represented the lumen of the heart and great vessels. This model was qualitatively verified in conjunction with the CT images by the Consultant Radiologist. The model was utilised immediately preoperatively and was considered very helpful. The surgical team felt that the model was of use, particularly in the setting of dextrocardia. The colour-coding provided additional benefit. Conclusion - We suggest that colour-coded models of CHDs be utilised as an adjunct to anatomic study and surgical planning. Surgeons operate in a 3D world relying on 2D imaging for preoperative planning; 3D models may aid understanding of complex anatomy.

Where applicable, experiments conform with Society ethical requirements