Application of 3D printing in the surgical planning of hypertrophic obstructive cardiomyopathy and physician-patient communication: a preliminary study

Abstract

Background: The aim of this study was to evaluate the effect of 3-dimensional (3D) printing in treatment of hypertrophic obstructive cardiomyopathy (HOCM) and its roles in doctor-patient communication.

Methods: 3D-printed models were constructed preoperatively and postoperatively in seven HOCM patients received surgical treatment. Based on multi-slice computed tomography (CT) images, regions of disorder were segmented using the Mimics 19.0 software (Materialise, Leuven, Belgium). After generating an STL-file (StereoLithography file) with patients' data, the 3D printer (Objet350 Connex3, Stratasys Ltd., USA) created a 3D model. The pre- and post-operative 3D-printed models were used to make the surgical plan preoperatively and evaluate the outcome postoperatively. Meanwhile, a questionnaire was designed for patients and their relatives to learn the effectiveness of the 3D-printed prototypes in the preoperative conversations.

Results: The heart anatomies were accurately printed with 3D technology. The 3D-printed prototypes were useful for preoperative evaluation, surgical planning, and practice. Preoperative and postoperative echocardiographic evaluation showed left ventricular outflow tract (LVOT) obstruction was adequately relieved (82.71±31.63 to 14.91±6.89 mmHg, P<0.001), the septal thickness was reduced from 21.57±4.65 to 17.42±5.88 mm (P<0.001), and the SAM disappeared completely after the operation. Patients highly appreciated the role of 3D model in preoperative conversations and the communication score was 9.11±0.38 points.

Conclusions: A 3D-printed model is a useful tool in individualized planning for myectomies and represent a useful tool for physician-patient communication.

Keywords: 3D printing; Heart model; hypertrophic cardiomyopathy; myectomy.

Figure 1

A sample of workflow is shown diagrammatically from identification of adults with hypertrophic obstructive cardiomyopathy to creation of a virtual and three-dimensional (3D) printed model.

Figure 2

3D model of hypertrophic obstructive cardiomyopathy in longitudinal section. 3D Model of patient before (above) and after (below) myectomy procedure. (A) The 3D virtual model shows LVOT was significantly enlarged after the procedure; (B) the IVS was colored red and the green shaded area marks the mitral valve area in the corresponding 3D-printed model. The solid line indicates the potential incision of myectomy and the hypertrophic IVS which disappear postoperatively; (C) the narrowed LVOT (the channel between the dashed lines) and systolic anterior motion of mitral valve was illustrated in the larger version of the LVOT; (D) the enlarged LOVT after the myectomy. LVOT, left ventricular outlet tract; IVS, interventricular septum; MV, mitral valve; MVA, anterior leaflet of mitral valve.

Figure 3

The superior aspect of the 3D model of hypertrophic obstructive cardiomyopathy. 3D Model of patient before (A,B) and after (C,D) myectomy procedure. The images show the superior aspect of the left heart which the aortic valve is removed. The dashed line indicates the mitral valve annulus. The anterior leaflet forward motion toward the IVS is also obvious in the larger version of the aortic root. The shadow area marked R indicated the removed hypertrophic IVS in the operation. AV, aortic valve; MV, mitral valve; SAM, systolic anterior motion; IVS, interventricular septum; R, resect part of hypertrophic IVS.