Virtual 3D reconstruction of L-TGA blood volume


Physical 3D-printed model in HeartPrint® Flex

Congenital heart defects affect eight out of every one thousand newborns. Although many patients do not require immediate treatment, most will require a surgical or catheter based intervention during their lifetime. The most complex cases can involve multiple anomalies and require comprehensive pre-interventional or surgical planning. This case explored the feasibility of using a 3D-printed, patient-specific, compliant model of a patient’s heart anatomy for pre-surgical planning. The model derived from medical images proved to be a powerful supplement to traditional image-only planning; particularly for this complex case.


From Virtual to Tangible: HeartPrint® Models

In recent years, 3D anatomical reconstructions from medical images have become an established tool to assist in diagnostics, educational purposes and intervention planning. Though the Mimics® Innovation Suite has incredible 3D visualization and measurement tools for characterizing patient anatomy, holding a physical model in your own hands delivers an even better understanding. This case involved a patient with complex congenital heart disease consisting of an L-Transposition of the Great Arteries, subpulmonic stenosis, and a ventricular septal defect complicated by a straddling tricusipid valve and a hypoplastic right ventricle.


HeartPrint® Flex : Realistic Arterial Tissue Properties

The 3D Printing technology offers a wide variety of material options with both rigid and compliant properties. For this cardiac application, the HeartPrint Flex process was selected because the material is comparable to arterial tissue properties. The resulting model was transparent and sectioned in the optional plane for viewing the anomalies even before setting foot in the operating room. 3D Printing technology proved to be the ideal way to visualize the complex structures in an accurate, realistic, and tangible way.


Obtaining a Reconstructed Anatomical Heart Model

The Mimics Innovation Suite streamlined the process for creating a physical 3D model. The process began with a cardiac magnetic resonance study which was followed by the administration of gadolinium for a volumetric acquisition of the chest; and finally, 3D Printing an exact, physical replica of the anatomy. There were four steps to the process:

1. Gadolinium-enhanced cardiac magnetic resonance images of the patient were acquired.
2. The lumen was segmented from CMR images by using the Mimics Innovation Suite.
3. A 3D reconstruction of the cardiac anatomy was generated and sectioned before preparing the file for 3D Printing, again using the Mimics Innovation Suite.
4. The anatomy was printed using Materialise’s proprietary HeartPrint Flex process.









The Value of a 3D-Printed Model

3D Printing had the advantage of being accurate, fast and relatively inexpensive, while clearly showing the relationship between the ventricular septal defect, the size of the systemic ventricle, and the straddling tricuspid valve tissues. Understanding these structures was critical before operating. The model provided an ideal way to make a complete assessment. The presence of hypoplastic right ventricle when viewed by the 3D model confirmed the findings of the 2D studies and moved the decision away from a two ventricle repair and towards a Glenn shunt and Fontan palliation. It is hard to imagine approaching any complex case without a 3D-printed model.

The Standard in ‘Engineering on AnatomyTM

The Mimics Innovation Suite turns 3D image data into high-quality digital models in an accurate and efficient way. Starting from CT, MRI or 3D ultrasound images, the Mimics Innovation Suite offers the most advanced image segmentation, the broadest anatomical measurement options, powerful CAD tools for Engineering on Anatomy and 3D Printing, and accurate model preparation for FEA and CFD.
In this case, the Medical edition of the Mimics Innovation Suite was used to:

  • Provide a highly accurate cardiovascular 3D-printed model in a timely manner
  • Assist in the pre-surgical planning for the treatment of these complex congenital heart defects
  • Supplement traditional imaging techniques and  confirm the best way forward