Scaffold System to Treat Aneurysms

Tech ID:

Scaffold to Treat Aneurysms, Optimized to Direct Tissue Development and Control Blood Flow

Background:  Abdominal aortic aneurysms, commonly referred to as AAA, consist of a 50% enlargement of the abdominal aorta. While the exact cause of AAA is not well understood, it is believed to be a complex process involving loss of elasticity and strength, leading to arterial expansion. Studies show that 3% of all individuals aged 50 and over, have AAA. Only 25% of patients with ruptured aneurysms reach the hospital and only 10% make it to the operating room.  Because of such high mortality rates, it is important to treat the aneurysm before it ruptures.

Current treatment of the AAA includes either open surgery or endovascular aneurysm repair (EVAR), depending on the patient physiology and pathology.  EVAR utilizes stent technology to place the graft over the aneurysm and into the iliofemoral arteries.  The graft serves to block off the aneurismal segment of the aorta without extensive damage to the arteries.  Currently there are several FDA approved stent-grafts.  However, because the graft is meant to separate the unhealthy portion from the blood flow, inherent problems exist such as endoleaks after implantation, in which blood seeps between the graft and the lumen of the aorta, reaching the aneurysm.  Additional risks associated with EVAR are due to the permanent introduction of a material that is not bioactive. For example, current bioinert materials can result in a fibrous capsule as a result of the immune system’s rejection response. 

Invention:  Such risks may be circumvented with this current invention from the UT Health Science Center at San Antonio, which introduces a biodegradable scaffold that provides a three dimensional structure on which the cells can proliferate and organize into a new tissue, allowing native cells to infiltrate the scaffold and remodel into an aortic wall of proper diameter. Infiltrating cells will come from both the blood flowing through the scaffold as well as the surrounding tissue.  Initially, the cells will act according to the wound healing response.  Then the initially adhered cells signal for other more appropriate cells to adhere and migrate through the scaffold.

As different cells adhere, migrate, and proliferate, a remodeling process takes place in which extracellular matrix components and scaffold fibers are broken down in some areas and bolstered in others.  Therefore, as time progresses the scaffold is slowly replaced by functional tissue organized in response to physiological conditions.  Eventually the scaffold will be completely degraded leaving tissue in its place of the correct shape and containing vital structural components.  At this point the aneurysm will be minimized or no longer present. Unlike current EVAR treatments which try to present an impermeable barrier, this scaffold will initially be permeable to allow cell infiltration.  Once appropriate cells adhere, put down extracellular matrix components and proliferate, the scaffold will become substantially impermeable.  Furthermore, the scaffold is biodegradable, so that as new tissue is formed, it will slowly be broken down by natural metabolic pathways. Unlike current tissue engineered blood vessels, the scaffold may be positioned within the damaged cardiovascular tissue with minimum excision or damage to surrounding tissue.


Dr. Steven R. Bailey, M.D. Chief of the Division of Cardiology, UTHSCSA
Dr. C. Mauli Agrawal, Ph.D., P.E., Dean, College of Engineering, UTSA
Dr. Jordan Massey, Ph.D.

For information contact:
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C. Mauli Agrawal
Steven Bailey
Jordan Kaufmann
Patent Information: