Preliminary study of the application of transthoracic echocardiography-guided three-dimensional printing for the assessment of structural heart disease

Translating Imaging Into 3D Printed Cardiovascular Phantoms

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3D printed patient specific phantoms can visualize complex cardiovascular anatomy

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Common imaging modalities for 3D printing are CCT and CMR

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Material jetting/PolyJet and stereolithography are widely used printing techniques

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Standardized validation is warranted to compare different 3D printing technologies

Translation of imaging into 3-dimensional (3D) printed patient-specific phantoms (3DPSPs) can help visualize complex cardiovascular anatomy and enable tailoring of therapy. The aim of this paper is to review the entire process of phantom production, including imaging, materials, 3D printing technologies, and the validation of 3DPSPs. A systematic review of published research was conducted using Embase and MEDLINE, including studies that investigated 3DPSPs in cardiovascular medicine. Among 2,534 screened papers, 212 fulfilled inclusion criteria and described 3DPSPs as a valuable adjunct for planning and guiding interventions (n = 108 [51%]), simulation of physiological or pathological conditions (n = 19 [9%]), teaching of health care professionals (n = 23 [11%]), patient education (n = 3 [1.4%]), outcome prediction (n = 6 [2.8%]), or other purposes (n = 53 [25%]). The most common imaging modalities to enable 3D printing were cardiac computed tomography (n = 131 [61.8%]) and cardiac magnetic resonance (n = 26 [12.3%]). The printing process was conducted mostly by material jetting (n = 54 [25.5%]) or stereolithography (n = 43 [20.3%]). The 10 largest studies that evaluated the geometric accuracy of 3DPSPs described a mean bias <±1 mm; however, the validation process was very heterogeneous among the studies. Three-dimensional printed patient-specific phantoms are highly accurate, used for teaching, and applied to guide cardiovascular therapy. Systematic comparison of imaging and printing modalities following a standardized validation process is warranted to allow conclusions on the optimal production process of 3DPSPs in the field of cardiovascular medicine.

Hemodynamic testing using three-dimensional printing and computational fluid dynamics preoperatively may provide more information in mitral repair than traditional image dataset

Background

Mitral valve repair (MVR) has been considered superior to mitral replacement for degenerative MV disease and even rheumatic diseases. However, the repair rate varies widely depending on the medical center and the surgeons’ experience. The aim of our study was to apply three-dimensional printing (3DP) and computational fluid dynamics (CFD) in surgical simulation to provide reference for surgical decision-making, especially for inexperienced surgeons.

Methods

Our study included retrospective and prospective cohorts. We first enrolled the retrospective cohort of 35 patients who were prepared to have MVR, aiming at exploring the feasibility of surgical simulation using 3DP and CFD. Three-dimensional transesophageal echocardiography (3D-TEE) and computed tomography angiography (CTA) were performed for all patients, and imaging data were fused to construct a 3D digital model. Next, the model was used to make the 3DP dynamic model and for CFD analysis. Mitral repair was simulated in both the 3DP dynamic model and CFD to predict surgical outcomes (grade of regurgitation and vena contracta width) and possible complications (systolic anterior motion, left ventricular outflow tract obstruction). Second, a prospective cohort of 20 patients was studied with 10 patients placed in a 3DP-guided group and 10 in an image-guided group. Rate of transformation to mitral replacement, surgery time, surgical outcomes, and surgical complications were compared between groups.

Results

Of the 35 patients retrospectively enrolled, 14 underwent MVR and 21 were transferred to mitral replacement. Surgical simulation for the 14 MVR patients showed high consistency with in vivo results. The result of surgical simulation for the 21 patients transferred to mitral replacement showed that 7 might have benefited from MVR. In the prospective cohort, the rate of transformation to mitral replacement and surgery time in the 3DP-guided group were significantly lower than those in the image-guided group.

Conclusions

3DP and CFD models based on image data can be used for in vitro surgical simulation. These emerging technologies are now changing traditional models of diagnosis and treatment, and the role of imaging data will no longer be limited to diagnosis but will contribute more to assisting surgeons in choosing treatment strategies.

Three-dimensional printing for cardiovascular diseases: from anatomical modeling to dynamic functionality

Three-dimensional (3D) printing is widely used in medicine. Most research remains focused on forming rigid anatomical models, but moving from static models to dynamic functionality could greatly aid preoperative surgical planning. This work reviews literature on dynamic 3D heart models made of flexible materials for use with a mock circulatory system. Such models allow simulation of surgical procedures under mock physiological conditions, and are; therefore, potentially very useful to clinical practice. For example, anatomical models of mitral regurgitation could provide a better display of lesion area, while dynamic 3D models could further simulate in vitro hemodynamics. Dynamic 3D models could also be used in setting standards for certain parameters for function evaluation, such as flow reserve fraction in coronary heart disease. As a bridge between medical image and clinical aid, 3D printing is now gradually changing the traditional pattern of diagnosis and treatment.

Clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: adult cardiac conditions

BACKGROUND

Medical 3D printing as a component of care for adults with cardiovascular diseases has expanded dramatically. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides appropriateness criteria for adult cardiac 3D printing indications.

METHODS

A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with a number of adult cardiac indications, physiologic, and pathologic processes. Each study was vetted by the authors and graded according to published guidelines.

RESULTS

Evidence-based appropriateness guidelines are provided for the following areas in adult cardiac care; cardiac fundamentals, perioperative and intraoperative care, coronary disease and ischemic heart disease, complications of myocardial infarction, valve disease, cardiac arrhythmias, cardiac neoplasm, cardiac transplant and mechanical circulatory support, heart failure, preventative cardiology, cardiac and pericardial disease and cardiac trauma.

CONCLUSIONS

Adoption of common clinical standards regarding appropriate use, information and material management, and quality control are needed to ensure the greatest possible clinical benefit from 3D printing. This consensus guideline document, created by the members of the RSNA 3D printing Special Interest Group, will provide a reference for clinical standards of 3D printing for adult cardiac indications.

Feasibility of Device Closure for Multiple Atrial Septal Defects With an Inferior Sinus Venosus Defect: Procedural Planning Using Three-Dimensional Printed Models

BACKGROUND

Multiple atrial septal defects (ASD) with an inferior sinus venosus defect (SVD) have always been considered to be contraindications for interventional therapy. On the basis of early experience using a patent ductus arteriosus (PDA) occluder for interventional treatment for inferior ASD, this study investigated the feasibility of transcatheter closure of multiple ASDs with an inferior SVD under the guidance of three-dimensional (3D) printed heart models.

METHODS

Between August 2016 and February 2017, five patients who were diagnosed with multiple ASDs with an inferior SVD at the First Affiliated Hospital of Xi'an Jiaotong University underwent cardiac computed tomography (CT) scans and three-dimensional (3D) echocardiography to generate heart disease models by a 3D printing technique. The best occlusion program was determined through a simulated closure on the model. Percutaneous device closure of multiple ASDs with an inferior SVD was performed following the predetermined program, guided only by fluoroscopy. Follow-up included electrocardiography, transthoracic echocardiography, and transoesophageal echocardiography.

RESULTS

Three-dimensional (3D) printed models for all five patients were produced successfully. Four (4) patients had a secundum ASD with an inferior sinus venosus ASD, and one patient had a patent foramen ovale (PFO) with an inferior sinus venosus ASD. All patients were successfully treated with interventional therapy. Inferior sinus venosus ASD was percutaneously closed using the PDA occluder, and the additional secundum ASD or PFO in each patient was percutaneously closed using an ASD or PFO occluder at the same time. There was no device embolisation, procedure-related death or pericardial tamponade. During the 1-year follow-up, a minor residual shunt was detected in one patient.

CONCLUSION

The use of 3D printed ASD models provides a useful reference for transcatheter device closure of multiple ASD with an inferior SVD. This approach can provide a new treatment strategy for inferior sinus venosus ASD, which has been considered a contraindication for interventional therapy. However, long-term follow-up in a large number of patients is still warranted.