@article {NGUYEN2019, title = {Dynamic Three-Dimensional Geometry of the Tricuspid Valve Annulus in Hypoplastic Left Heart Syndrome with a Fontan Circulation}, journal = {Journal of the American Society of Echocardiography}, year = {2019}, abstract = {

Background Tricuspid regurgitation (TR) is a significant contributor to morbidity and mortality in patients with hypoplastic left heart syndrome. The goal of this study was to characterize the dynamic annular motion of the tricuspid valve in patients with HLHS with a Fontan circulation and assess the relation to tricuspid valve function. Methods Tricuspid annuli of 48 patients with HLHS with a Fontan circulation were modeled at end-diastole, mid-systole, end-systole, and mid-diastole using transthoracic three-dimensional echocardiography and custom code in 3D Slicer. The angle of the anterior papillary muscle (APM) relative to the annular plane in each systolic phase was also measured. Results Imaging was performed 5.0\ years (interquartile range, 2{\textendash}11\ years) after Fontan operation. The tricuspid annulus varies in shape significantly throughout the cardiac cycle, changing in sphericity (P\ \<\ .001) but not in annular height or bending angle. In univariate modeling, patients with significant TR had larger changes in septolateral diameter, lateral quadrant area, and posterior quadrant area (P\ \<\ .05 for all) as well as lower (more laterally directed) APM angles (P\ \<\ .001) than patients with mild or less TR. In multivariate modeling, a 1\ mm/(body surface area)0.5 increase in the maximum change in septolateral diameter was associated with a 1.7-fold increase in having moderate or greater TR, while a 10{\textdegree} decrease in APM angle at mid-systole was associated with an almost 2.5-fold increase in moderate or greater TR (P\ <=\ .01 for all). Conclusions The tricuspid annulus in patients with HLHS with a Fontan circulation changes in shape significantly throughout the cardiac cycle but remains relatively planar. Increased change in septolateral diameter and decreased APM angle are strongly associated with the presence of TR. These findings may inform annuloplasty methods and subvalvular interventions in these complex patients.

}, keywords = {Congenital heart disease, Echocardiography, Valvular heart disease}, issn = {0894-7317}, doi = {https://doi.org/10.1016/j.echo.2019.01.002}, url = {http://www.sciencedirect.com/science/article/pii/S0894731719300021}, author = {Alexander V. Nguyen and Andras Lasso and HannahH Nam and Jennifer Faerber and Ahmed H. Aly and Alison M. Pouch and Adam B. Scanlan and FrancisX McGowan and Laura Mercer-Rosa and Meryl S. Cohen and John Simpson and Gabor Fichtinger and MatthewA Jolley} } @article {doi:10.1002/ccd.27962, title = {Toward predictive modeling of catheter-based pulmonary valve replacement into native right ventricular outflow tracts}, journal = {Catheterization and Cardiovascular Interventions}, year = {2018}, month = {11/2018}, abstract = {

Abstract Background Pulmonary insufficiency is a consequence of transannular patch repair in Tetralogy of Fallot (ToF) leading to late morbidity and mortality. Transcatheter native outflow tract pulmonary valve replacement has become a reality. However, predicting a secure, atraumatic implantation of a catheter-based device remains a significant challenge due to the complex and dynamic nature of the right ventricular outflow tract (RVOT). We sought to quantify the differences in compression and volume for actual implants, and those predicted by pre-implant modeling. Methods We used custom software to interactively place virtual transcatheter pulmonary valves (TPVs) into RVOT models created from pre-implant and post Harmony valve implant CT scans of 5 ovine surgical models of TOF to quantify and visualize device volume and compression. Results Virtual device placement visually mimicked actual device placement and allowed for quantification of device volume and radius. On average, simulated proximal and distal device volumes and compression did not vary statistically throughout the cardiac cycle (P = 0.11) but assessment was limited by small sample size. In comparison to actual implants, there was no significant pairwise difference in the proximal third of the device (P \> 0.80), but the simulated distal device volume was significantly underestimated relative to actual device implant volume (P = 0.06). Conclusions This study demonstrates that pre-implant modeling which assumes a rigid vessel wall may not accurately predict the degree of distal RVOT expansion following actual device placement. We suggest the potential for virtual modeling of TPVR to be a useful adjunct to procedural planning, but further development is needed.

}, keywords = {Magnetic Resonance Imaging, percutaneous pulmonary valve implantation, prosthetic heart valve, tetralogy of Fallot}, doi = {10.1002/ccd.27962}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ccd.27962}, author = {MatthewA Jolley and Andras Lasso and HannahH Nam and Dinh, Patrick V. and Adam B. Scanlan and Alexander V. Nguyen and Anna Ilina and Morray, Brian and Glatz, Andrew C. and FrancisX McGowan and Whitehead, Kevin and Dori, Yoav and Robert C. Gorman and Robert C. Gorman and Gabor Fichtinger and Gillespie, Matthew J.} } @article {Scanlan2017, title = {Comparison of 3D Echocardiogram-Derived 3D Printed Valve Models to Molded Models for Simulated Repair of Pediatric Atrioventricular Valves}, journal = {Pediatric Cardiology}, year = {2017}, month = {Nov}, abstract = {

Mastering the technical skills required to perform pediatric cardiac valve surgery is challenging in part due to limited opportunity for practice. Transformation of 3D echocardiographic (echo) images of congenitally abnormal heart valves to realistic physical models could allow patient-specific simulation of surgical valve repair. We compared materials, processes, and costs for 3D printing and molding of patient-specific models for visualization and surgical simulation of congenitally abnormal heart valves. Pediatric atrioventricular valves (mitral, tricuspid, and common atrioventricular valve) were modeled from transthoracic 3D echo images using semi-automated methods implemented as custom modules in 3D Slicer. Valve models were then both 3D printed in soft materials and molded in silicone using 3D printed {\textquoteleft}{\textquoteleft}negative{\textquoteright}{\textquoteright} molds. Using pre-defined assessment criteria, valve models were evaluated by congenital cardiac surgeons to determine suitability for simulation. Surgeon assessment indicated that the molded valves had superior material properties for the purposes of simulation compared to directly printed valves (p{\th}inspace}\<{\th}inspace}0.01). Patient-specific, 3D echo-derived molded valves are a step toward realistic simulation of complex valve repairs but require more time and labor to create than directly printed models. Patient-specific simulation of valve repair in children using such models may be useful for surgical training and simulation of complex congenital cases.

}, issn = {1432-1971}, doi = {10.1007/s00246-017-1785-4}, url = {https://doi.org/10.1007/s00246-017-1785-4}, author = {Adam B. Scanlan and Alexander V. Nguyen and Anna Ilina and Andras Lasso and Cripe, Linnea and Jegatheeswaran, Anusha and Silvestro, Elizabeth and FrancisX McGowan and Christopher E. Mascio and Fuller, Stephanie and Spray, Thomas L. and Meryl S. Cohen and Gabor Fichtinger and MatthewA Jolley} } @article {Ilina2017b, title = {Creating patient-specific anatomical models from highly elastic materials using 3D-printed molds}, year = {2017}, address = {London, Canada}, keywords = {cardiac, heart, heart valve models, heart valves, molds, pediatric, Phantoms}, author = {Anna Ilina and Andras Lasso and MatthewA Jolley and Brittany Wohler and Alexander V. Nguyen and Adam B. Scanlan and Zachary M C Baum and FrancisX McGowan and Gabor Fichtinger} } @conference {DBLP:conf/fimh/PouchALNSMFGGYJ17, title = {Image Segmentation and Modeling of the Pediatric Tricuspid Valve in Hypoplastic Left Heart Syndrome}, booktitle = {Functional Imaging and Modelling of the Heart - 9th International Conference, {FIMH} 2017, Toronto, ON, Canada, June 11-13, 2017, Proceedings}, year = {2017}, pages = {95{\textendash}105}, doi = {10.1007/978-3-319-59448-4_10}, url = {https://doi.org/10.1007/978-3-319-59448-4_10}, author = {Alison M. Pouch and Ahmed H. Aly and Andras Lasso and Alexander V. Nguyen and Adam B. Scanlan and FrancisX McGowan and Gabor Fichtinger and Robert C. Gorman and Robert C. Gorman and Paul A. Yushkevich and MatthewA Jolley} } @conference {Ilina2017a, title = {Patient-specific pediatric silicone heart valve models based on 3D ultrasound}, booktitle = {SPIE Medical Imaging 2017}, volume = {10135}, year = {2017}, month = {03/2017}, publisher = {SPIE Medical Imaging}, organization = {SPIE Medical Imaging}, address = {Orlando, FL, United States, Feb. 16, 2017}, abstract = {

PURPOSE: Patient-specific heart and valve models have shown promise as training and planning tools for heart surgery, but physically realistic valve models remain elusive. Available proprietary, simulation-focused heart valve models are generic adult mitral valves and do not allow for patient-specific modeling as may be needed for rare diseases such as congenitally abnormal valves. We propose creating silicone valve models from a 3D-printed plastic mold as a solution that can be adapted to any individual patient and heart valve at a fraction of the cost of direct 3D-printing using soft materials.

METHODS: Leaflets of a pediatric mitral valve, a tricuspid valve in a patient with hypoplastic left heart syndrome, and a complete atrioventricular canal valve were segmented from ultrasound images. A custom software was developed to automatically generate molds for each valve based on the segmentation. These molds were 3D-printed and used to make silicone valve models. The models were designed with cylindrical rims of different sizes surrounding the leaflets, to show the outline of the valve and add rigidity. Pediatric cardiac surgeons practiced suturing on the models and evaluated them for use as surgical planning and training tools.

RESULTS: Five out of six surgeons reported that the valve models would be very useful as training tools for cardiac surgery. In this first iteration of valve models, leaflets were felt to be unrealistically thick or stiff compared to real pediatric leaflets. A thin tube rim was preferred for valve flexibility.

CONCLUSION: The valve models were well received and considered to be valuable and accessible tools for heart valve surgery training. Further improvements will be made based on surgeons{\textquoteright} feedback.

Keywords: surgery, training, heart valve models, pediatric, patient-specific, 3D-printing, congenital heart disease, mitral valve, tricuspid valve, complete atrioventricular canal defect, ultrasound

}, author = {Anna Ilina and Andras Lasso and MatthewA Jolley and Brittany Wohler and Alexander V. Nguyen and Adam B. Scanlan and Zachary M C Baum and FrancisX McGowan and Gabor Fichtinger} }