3D Virtual Reality based baffle planning for Left Ventricle to Aorta routing in complex congenital heart surgery - a feasibility study.

Background: Left Ventricle to Aorta baffling is a critical step in complex CHD surgeries, conventionally guided by intraoperative assessment.

We studied feasibility and novel workflows for using immersive 3D technologies (Virtual Reality and 3D printing) for bespoke preoperative planning, simulation, and intraoperative placement of intracardiac baffles (LV-Aorta) in complex CHD surgeries, and its impact on surgical outcomes.

Methods: Prospective study conducted in a tertiary center with dedicated 3D Printing & VR Laboratory. 3DVR medical modelling techniques (using cardiac CT data, Vea Simulations software) were used to analyse intracardiac spatial anatomy, simulate LV-Aorta baffle placement and plan surgical approach in a series of 17 complex CHD cases undergoing surgical repair.

Digitally designed baffles were analysed for morphometrics, and 3D printed using flexible (elastic) resin into templates for guiding intraoperative baffle creation. Adherence to simulation-based surgical plan and ease of baffle creation were assessed in operating room.

Results: 17 complex CHD cases (median age 6.8 years) included - DORV (n=9; 2 with common AV canal, 3 with superoinferior ventricles), double-outlet both ventricles (n=1), CCTGA (n=5), d-TGA (n=2). Situs abnormalities (5/16), dextrocardia (6/16), pulmonary stenosis/atresia (13/16) added to complexity. 13/16 had been previously surgically palliated. (Table)

Digital twins were created, 3DVR assessment and baffle planning were successfully done for all. Intraoperative findings were concurrent with 3DVR predictions in all cases. Patient-specific 3D-printed baffles allowed tangible morphometric assessment and served as physical templates to pre-cut and shape pericardial patches in operating room. Initially prepared with 1cm margin along the predicted shape the patches were trimmed as they were sutured in position. Deviation from predicted morphometrics was < 10-15%. We also developed workflow for printing the digitally created baffle design onto simple paper in 1:1 scale, eliminating the necessity for 3D printed baffle templates.

Conclusion: This study for the first time demonstrates the feasibility, workflow and translational impact of using advanced 3D technologies for 3DVR based presurgical planning of intraventricular tunneling in complex CHD surgery by using physical formats of digital baffle designs for aiding real-life surgical procedures. Our demonstration of how computationally designed complex baffles can be printed on paper in 1:1 scale by repurposing existing CAD tools can be a major disruptor that may enable even low resource centers to adapt these technologies at low cost using freeware and relatively inexpensive devices, without need for 3D printers.

Cases were visualized in 3DVR (Via Simulations, Poland). Digital baffle simulations were 3D printed using flexible photopolymeric resin that could be unfolded. Digitally unfolded baffle designs were 3D printed and also printed on plain paper to be used as templates during surgery.
3D printed baffle morphometrics
Flow chart showing the workflow for creation of templates for baffle design.