Computational Modeling for Preprocedural Planning of a Complex LVAD Exchange

Purpose

Methodologies were utilized for pre-procedural planning that include 3D computational imaging, virtual device implantation, and 3D printed models that were noted to provide large didactical improvements for the surgical team. A procedure was planned to replace an existing HeartWare™ (HVAD) with a Heartmate 3™ device due to thrombus formations in the LV around the HVAD inflow cannula. The printed 3D models for the LVAD exchange procedure were brought to the operating room for planning by the care team.

Methods

Thoracic CT-scan images were imported into Materialise Mimics software (Fig 1A), where digital segmentations of the epicardial surface, chamber blood volumes, HVAD location and orientation, and ribcage were generated (Fig 1B) and 3D printed (Fig 1C). Additionally, a model of the HeartMate 3™ that was to be implanted, was digitally generated and printed and then inserted into the printed model (Fig 1D).

Results

These modeling efforts shows that there would be minimal space between the intended implant of HeartMate 3™ pump and the ribs, as it is larger than the HeartWare™ pump to be replaced (Fig 2A-E). The blood volume of the heart model (Fig 2F) also highlighted the location of clots relative to the original pump.

Conclusion

The pre-procedural utilization of these computational models helped elucidate some of the potential challenges from the sizing and placement of the new LVAD, relative to the surgical approach (sternotomy vs thoracotomy). Additionally, the models contributed to the education of the entire surgical-care team prior to performing this complex surgical procedure.