3D printing based on cardiac CT assists anatomic visualization prior to transcatheter aortic valve replacement

Abstract

Background 3D printing is a promising technique that may have applications in medicine, and there is expanding interest in the use of patient-specific 3D models to guide surgical interventions. Objective To determine the feasibility of using cardiac CT to print individual models of the aortic root complex for transcatheter aortic valve replacement (TAVR) planning as well as to determine the ability to predict paravalvular aortic regurgitation (PAR). Methods This retrospective study included 16 patients (9 with PAR identified on blinded interpretation of post-procedure trans-thoracic echocardiography and 7 age, sex, and valve size-matched controls with no PAR). 3D printed models of the aortic root were created from pre-TAVR cardiac computed tomography data. These models were fitted with printed valves and predictions regarding post-implant PAR were made using a light transmission test. Results Aortic root 3D models were highly accurate, with excellent agreement between annulus measurements made on 3D models and those made on corresponding 2D data (mean difference of −0.34 mm, 95% limits of agreement: ± 1.3 mm). The 3D printed valve models were within 0.1 mm of their designed dimensions. Examination of the fit of valves within patient-specific aortic root models correctly predicted PAR in 6 of 9 patients (6 true positive, 3 false negative) and absence of PAR in 5 of 7 patients (5 true negative, 2 false positive). Conclusions Pre-TAVR 3D-printing based on cardiac CT provides a unique patient-specific method to assess the physical interplay of the aortic root and implanted valves. With additional optimization, 3D models may complement traditional techniques used for predicting which patients are more likely to develop PAR.

Modelling of aortic aneurysm and aortic dissection through 3D printing

“…Some recent studies have shown the applications of 3D printing in cardiovascular disease, such as coronary artery disease, aortic and pulmonary venous valve disease 8, 9, 10, 11, 12. 3D printing technology also allows for the production of individualised cardiac stents to reduce the rate of in‐stent re‐stenosis 1…”

Cardiothoracic Applications of 3-dimensional Printing

“…Deployment of the same device into the 3D model as implanted in the patient was reported to improve anticipation of potential difficulties and to have the potential to help minimize peri- and post-operative complications [7]. More recently, we reported the use of flexible 3D printed models of the aortic root complex derived from routine TAVR planning CT angiography to predict perivalvular leak in a small series of patients [11]. 3D printed models of the implanted valves (26 or 29 mm Edwards SAPIEN XT in this patient series) with a closed configuration and corresponding to the valve implanted in each patient were carefully positioned in the patient’s printed aortic root model.…”

Three-Dimensional Printing in Cardiovascular Disease: Verification of Diagnostic Accuracy of 3D Printed Models

“…[18][19][20] Similarly, good to excellent agreement has been reached between 3D printed models and original source 2D images for dimensional measurements of aortic valve, aortopulmonary artery, and aortic aneurysms. [21][22][23][24][25] However, in a recent study, Ho et al have indicated that the variances in aortic diameter measurements between 3D printed models and 2D contrastenhanced CT images exceeded 1.0 mm, which is beyond the standard deviation of 1.0 mm. 26 This highlights the potential limitations of using anatomic landmarks to measure accuracy of 3D printed hollow models, such as heart models or aneurysmal models.…”

“…Previous studies have reported the accuracy of 3D printed models of cardiovascular disease with good to excellent correlation between 3D printed models and original CT or MRI data. [21][22][23][24][25] However, these studies are limited in assessment of diameter changes in the selected anatomical regions, which failed to consider the whole shapes of vascular structures or aneurysms. Further, according to a recent systematic review, majority of the current studies compared 3D printed models with original source CT or MRI data, 12,[21][22][23][24] while only a few of them compared images of the scanned 3D printed models with original source imaging data (Figure 1).…”

“…[21][22][23][24][25] However, these studies are limited in assessment of diameter changes in the selected anatomical regions, which failed to consider the whole shapes of vascular structures or aneurysms. Further, according to a recent systematic review, majority of the current studies compared 3D printed models with original source CT or MRI data, 12,[21][22][23][24] while only a few of them compared images of the scanned 3D printed models with original source imaging data (Figure 1). 25,26 Discrepancy in measuring these dimensional diameters was shown in one of the studies with the maximal difference in vessel diameter being 3.2 mm, highlighting the limited accuracy of using diameter measurements.…”