Mia von Knorring, Areli Reyes, and Brandon Mukai recently submitted ‘Left Atrial Appendage Printing Procedure’ to the Faculty of the Biomedical Engineering Department at California Polytechnic State University – San Luis Obispo as a senior project. Exploring the use of 3D printed medical models for better visual aids in cardiac procedures, the research students aimed to help with the closing off the left atrial appendage.
The research is centered around assisting in the Watchman left atrial appendage closure procedure—a surgery only 100 surgeons in the US are trained for, meant to eliminate debris from the left atrial appendage that could cause a stroke. With a detailed 3D model, cardiac physiologists are better able to size and position the device. The study began with alterations to the original algorithm by Dr. Chris Porterfield, and then a final 3D design taken from CT scans, segmented, and 3D printed with PLA and PVA on an Ultimaker 3D printer (with a final cost of $118.94 after tax and shipping).
This is not just a research study exploring feasibility, but it explains how to create the 3D model from beginning to end, using 3D slicer—explaining the proper use of pixel density and understanding variances based on CT scan parameters. Ultimately, the research students explained that they would have included a more expanded threshold range, allowing for customizations depending on the left atrium and appendage.
They also added that in later use, 3D printing materials that are more like tissue would be an improvement:
“More flexible material is clinically relevant and could allow doctors to see the compression the Watchman could cause on the appendage to ensure that the device is correctly sized. Many sections of the procedure create variability that could change procedure outcomes,” stated the authors.
“We had the same lab assistant print all of our models, but he created certain parameters and printer features for all his prints that could possibly change between operators. To mitigate this risk, we recorded all notable parameters in our procedure. Variability could also arise when anatomy is being cropped. Operators could remove too much necessary anatomy or include more anatomy to create a larger model. In some patients, the pulmonary arteries are near the left atrial appendage.”
The authors make it clear too that these types of 3D slicing and printing are valid for a wide range of other applications and in other cardiac exercises such as sizing heart valves.
Guidelines for use of the model are included in the paper, and a request for user feedback, which so far has been taken by both Dr. Porterfield and his clinical specialist Sarah Griess.
“All comparisons had a p-value<.05, confirming repeatability and reproducibility of these features> confirming repeatability and reproducibility of these features. Depth measurements however resulted in a p-valve of .036 between operators. This discrepancy could be due to the challenging angle measurement,” concluded the researchers.
“Since the anatomical models are curved and irregularly shaped, it was difficult to measure the depth consistently between models. Lack of consistency PVA removal could also cause this design specification failure. On some models, PVA still remained in small cavities after post processing was completed even though we tried to remove as much as possible. Even though inconsistency between operators exists in the depth measurement, depth is not a critical measurement to Watchman sizing.”
Overall, the models were verified as accurate.
Today, 3D printing models abound within the medical arena for use in diagnosis, treatment, surgical planning, and more. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.[Source / Images: ‘Left Atrial Appendage Printing Procedure’]
Subscribe to Our Email Newsletter
Stay up-to-date on all the latest news from the 3D printing industry and recieve information and offers from thrid party vendors.
You May Also Like
3DPOD Episode 113: Industrial 3D Print Services with MakerVerse CEO Markus Seibold
MakerVerse is a Europe-based 3D printing service platform with global ambitions. The company aims to be the place where your orders for all 3D printing technologies come together and get...
3DPOD Episode 112: America Makes Executive Director John Wilczynski
John Wilczynski is the Executive Director of America Makes. Established a decade ago, America Makes performs research coordination, workforce training and education, standards development, and more for the additive manufacturing...
3DPOD Episode 111: 3D Printing Medical Devices with Ajay Panwar, Medtronic
In our latest episode, Ajay Panwar, Sr. Engineering Manager, Design Assurance at Medtronic, discusses the intersection of quality and 3D printing for the medical field. To be clear, Ajay does...
3DPOD Episode 110: Additive Manufacturing at Ricoh with Enrico Gallino
Enrico Gallino is a materials scientist with Ricoh. The Japanese firm has developed its own powder bed fusion (PBF) technology, rolled out a 3D printing service, has developed an anatomical...