Research brief: Researchers 3D print lifelike heart valve models

August 28, 2020

Researchers from the University of Minnesota, with support from Medtronic, have developed a groundbreaking process for multi-material 3D printing of lifelike models of the heart's aortic valve and the surrounding structures that mimic the exact look and feel of a real patient.

These patient-specific organ models, which include 3D-printed soft sensor arrays integrated into the structure, are fabricated using specialized inks and a customized 3D printing process. Such models can be used in preparation for minimally invasive procedures to improve outcomes in thousands of patients worldwide.

The research is published in Science Advances, a peer-reviewed scientific journal published by the American Association for the Advancement of Science (AAAS).

The researchers 3D printed what is called the aortic root, the section of the aorta closest to and attached to the heart. The aortic root consists of the aortic valve and the openings for the coronary arteries. The aortic valve has three flaps, called leaflets, surrounded by a fibrous ring. The model also included part of the left ventricle muscle and the ascending aorta.

"Our goal with these 3D-printed models is to reduce medical risks and complications by providing patient-specific tools to help doctors understand the exact anatomical structure and mechanical properties of the specific patient's heart," said Michael McAlpine, a University of Minnesota mechanical engineering professor and senior researcher on the study. "Physicians can test and try the valve implants before the actual procedure. The models can also help patients better understand their own anatomy and the procedure itself."

This organ model was specifically designed to help doctors prepare for a procedure called a Transcatheter Aortic Valve Replacement (TAVR) in which a new valve is placed inside the patient's native aortic valve. The procedure is used to treat a condition called aortic stenosis that occurs when the heart's aortic valve narrows and prevents the valve from opening fully, which reduces or blocks blood flow from the heart into the main artery. Aortic stenosis is one of the most common cardiovascular conditions in the elderly and affects about 2.7 million adults over the age of 75 in North America. The TAVR procedure is less invasive than open heart surgery to repair the damaged valve.

The aortic root models are made by using CT scans of the patient to match the exact shape. They are then 3D printed using specialized silicone-based inks that mechanically match the feel of real heart tissue the researchers obtained from the University of Minnesota's Visible Heart Laboratories. Commercial printers currently on the market can 3D print the shape, but use inks that are often too rigid to match the softness of real heart tissue.

On the flip side, the specialized 3D printers at the University of Minnesota were able to mimic both the soft tissue components of the model, as well as the hard calcification on the valve flaps by printing an ink similar to spackling paste used in construction to repair drywall and plaster.

Physicians can use the models to determine the size and placement of the valve device during the procedure. Integrated sensors that are 3D printed within the model give physicians the electronic pressure feedback that can be used to guide and optimize the selection and positioning of the valve within the patient's anatomy.

But McAlpine doesn't see this as the end of the road for these 3D-printed models.

"As our 3D-printing techniques continue to improve and we discover new ways to integrate electronics to mimic organ function, the models themselves may be used as artificial replacement organs," said McAlpine, who holds the Kuhrmeyer Family Chair Professorship in the University of Minnesota Department of Mechanical Engineering. "Someday maybe these 'bionic' organs can be as good as or better than their biological counterparts."
-end-
In addition to McAlpine, the team included University of Minnesota researchers Ghazaleh Haghiashtiani, co-first author and a recent mechanical engineering Ph.D. graduate who now works at Seagate; Kaiyan Qiu, another co-first author and a former mechanical engineering postdoctoral researcher who is now an assistant professor at Washington State University; Jorge D. Zhingre Sanchez, a former biomedical engineering Ph.D. student who worked in the University of Minnesota's Visible Heart Laboratories who is now a senior R&D engineer at Medtronic; Zachary J. Fuenning, a mechanical engineering graduate student; Paul A. Iaizzo, a professor of surgery in the Medical School and founding director of the U of M Visible Heart Laboratories; Priya Nair, senior scientist at Medtronic; and Sarah E. Ahlberg, director of research & technology at Medtronic.

This research was funded by Medtronic, the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health, and the Minnesota Discovery, Research, and InnoVation Economy (MnDRIVE) Initiative through the State of Minnesota. Additional support was provided by University of Minnesota Interdisciplinary Doctoral Fellowship and Doctoral Dissertation Fellowship awarded to Ghazaleh Haghiashtiani.

To read the full research paper, entitled "3D printed patient-specific aortic root models with internal sensors for minimally invasive applications," visit the Science Advances website.

University of Minnesota

Related Aortic Valve Articles from Brightsurf:

Aortic valve replacement during COVID-19 pandemic
The outcomes associated with deferred compared with expedited aortic valve replacement in patients with severe aortic stenosis during the COVID-19 pandemic are evaluated in this observational study.

Patients deferred for transcatheter aortic valve replacement because of COVID-19
This single-center study of 77 patients describes the outcomes of patients with symptomatic severe aortic stenosis during the COVID-19 pandemic.

Comprehensive evaluation of mitral valve-in-valve and valve-in-ring
Mitral valve-in-valve (ViV) and valve-in-ring (ViR) are alternatives to surgical reoperation in patients with recurrent mitral valve failure after previous surgical valve repair or replacement.

Research reveals link between high cholesterol levels and risk of aortic valve disease
Researchers from The George Institute for Global Health at the University of Oxford have found that while having high cholesterol levels does not influence your risk of aortic or mitral valve regurgitation, it does increase your risk of developing another major heart valve disease -- aortic stenosis.

NEJM: transcatheter aortic valve replacement shows similar safety outcomes as open-heart surgery
A new study from the Smidt Heart Institute at Cedars-Sinai and other centers nationwide shows that patients who underwent a minimally invasive transcatheter aortic-valve replacement (TAVR), had similar key 5-year clinical outcomes of death and stroke as patients who had traditional open-heart surgery to replace the valve.

Young age does not equal low risk for patients needing aortic valve replacement
While transcatheter aortic valve replacement (TAVR) continues to expand its pool of eligible patients, open heart surgery -- resulting in excellent patient survival and fewer strokes when compared to TAVR--is the best option for young and middle-aged adults with aortic valve disease -- at least for now.

Public reporting on aortic valve surgeries has decreased access, study finds
Public reporting on aortic valve replacement outcomes has resulted in fewer valve surgeries for people with endocarditis, a new study has found.

Bioengineers explore cardiac tissue remodeling after aortic valve replacement procedures
Researchers have developed biomaterial-based 'mimics' of heart tissues to measure patients' responses to an aortic valve replacement procedure, offering new insight into the ways that cardiac tissue re-shapes itself post-surgery.

New research addresses incidence of atrial fibrillation after aortic valve replacement
UAB investigators have outlined the incidence and implications of atrial fibrillation after transcatheter aortic valve implantation and surgical aortic valve replacement.

Defects in heart valve cilia during fetal development cause mitral valve prolapse
Genetic mutations in heart valve cells of the developing fetus lead to mitral valve prolapse, report a global collaborative of researchers, including Medical University of South Carolina investigators, in today's Science Translational Medicine.

Read More: Aortic Valve News and Aortic Valve Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.