Testing the compressive stiffness of endovascular devices Lucy Jonesa, Dr. Jonathan Vande Geestb a
Soft Tissue Biomechanics Laboratory, bDepartment of Bioengineering
Lucy Jones
Lucy Jones is a senior bioengineering student planning on graduating in the spring. Her interest in biomechanics motivated her to research with Dr. Jonathan Vande Geest at the Soft Tissue Biomechanics Laboratory for nearly two years. She has plans to work for Epic Systems following her undergraduate career.
Dr. Jonathan Vande Geest is a Professor in the Department of Bioengineering, Department of Mechanical Engineering and Material Science, the Department of Ophthalmology, the McGowan Institute for Regenerative Medicine, the Louis J. Fox Center for Vision Restoration, and the Vascular Medicine Institute at the Jonathan Vande University of Pittsburgh. He received his Geest, Ph.D. BS in Biomedical Engineering from the University of Iowa in 2000 and his PhD in Bioengineering from the University of Pittsburgh in 2005. Dr. Vande Geest began his career at the University of Arizona in the Department of Aerospace and Mechanical Engineering and joined the U of A’s Department of Biomedical Engineering in 2009. Dr. Vande Geest returned to the University of Pittsburgh in January of 2016.
Significance Statement
Peripheral artery disease (PAD) is a condition that causes the stenosis of arteries in the limbs. In this work, we used a fabricated 3D printed compression apparatus to assess the compressive resistance of several commercially available stents. Eventually, we will test the compressive resistance of our prototype endovascular device.
Category: Device Design
Keywords: endovascular device, compressive strength, peripheral artery disease, stent
40 Undergraduate Research at the Swanson School of Engineering
Abstract
Peripheral Artery Disease (PAD) is a condition characterized by the stenosis of arteries in the limbs. It can lead to negative consequences ranging from numbness, to amputation, or even death. Treatment methods for PAD include surgical intervention, or angioplasty, and stent implantation. However, these treatment methods are known to fail at high rates and could cause infection, vascular injury, or the restenosis of the artery. As a result, our team has created a new endovascular device that can exert force on the artery walls in order to keep it open while also maintaining the flexibility necessary to contend with complex mechanical regions such as the knee. In preparation for the assessment of our novel device, we have fabricated a simple 3D printed apparatus to evaluate the compressive resistance of our device and commercially available stents. In this work, we have assessed the compressive resistance of several commercially available stent devices. Our findings show that stents can generally withstand compressive loads up to 400g before they experience severe buckling. In the future, we intend to evaluate the compressive resistance of our endovascular device and compare it to that of stents.
1. Introduction
Peripheral Artery Disease (PAD) is a disease affecting approximately 202 million people worldwide [1]. This condition causes the stenosis of arteries and reduces blood flow to distal tissues. If left untreated, PAD will lead to stroke, amputation, or death. There are several available methods of treatment for this condition which include angioplasty, medication, and endovascular stent or stent-graft implantation. Stent grafts are endovascular devices made of a metal mesh and covered in fabric that following deployment expand the artery to keep it patent. People who experience PAD in their femoropopliteal artery need a solution that will be able to endure the complex mechanical challenges associated with that region of the leg (located behind the knee). Stent graft implementation has become a common treatment for PAD in extremities that experience loading from joint movement. Yet, stent graft failure is incredibly common, especially in the femoropopliteal artery, with an approximate 50% loss of patency two years following implantation [2]. Given the adverse effects of PAD, stent failure can be detrimental to the patients’ health and potentially fatal. As a result of the frequent failure of current stents, there has been an effort to make stents more adaptable to their mechanical environment. For instance, there has been success with the Misago, Supera, and Absolute stents, but the flaw of current stents still seems to be the rigidity of the design that is required to create a supportive scaffold inside stenosed arteries. Since stents are still not wholly effective in the long-term treatment of PAD in complex mechanical regions, our goal is to design a new device that will create a more flexible solution and allow for blood flow through the artery with a reduced risk of restenosis. For this phase in the development of our device, we
