3D heart model printing for preparation of percutaneous structural interventions: description of the technology and case report

Background: Structural heart disease, including valvular disease as well as congenital defects, causes important alterations in heart anatomy. As a result, individualised planning for both surgical and percutaneous procedures is crucial for procedural optimisation. Three dimensional (3D) rapid prototyping techniques are being utilised to aid operators in planning structural heart procedures. Aim: We intend to provide a description of 3D printing as a clinically applicable heart modelling technology for the planning of percutaneous structural heart procedures as well as to report our first clinical use of a 3D printed patient-specific heart model in preparation for a percutaneous mitral annuloplasty using the Mitralign percutaneous annuloplasty system. Methods: Retrospectively gated, contrast enhanced, multi-slice computed tomography (MSCT) scans were obtained. MSCT DICOM data was analysed using software that creates 3D surface files of the blood volume of specific regions of interest in the heart. The surface files are rendered using a software package that creates a solid model that can be printed using commercially available stereolithography machines. Results: The technique of direct percutaneous mitral annuloplasty requires advancement of a guiding catheter through the aorta, into the left ventricle, and requires the positioning of the tip of the catheter between the papillary muscles in close proximity to the mitral annulus. The 3D heart model was used to create a procedural plan to optimise potential device implantation. The size of the deflectable guiding catheter was selected on the basis of the patient's heart model. Target locations for annulus crossing wires were evaluated pre-procedurally using the individual patient's 3D heart model. In addition, the ability to position the Bident Catheter at the appropriate locations under the mitral annulus as well as the manoeuvrability between the papillary muscles were analysed on the heart model, enabling safe completion of the procedure, which resulted in a significant reduction in mitral regurgitation. Conclusions: 3D printing is a helpful tool in individualised planning for percutaneous structural interventions. Future studies are warranted to assess its role in preparing for percutaneous and surgical heart procedures.