Rersearch shows quick period of vein rebuilding after aneurysm

Overview

• Post By : Kumar Jeetendra


• Source: University of Pittsburgh


• Date: 26 Jan,2021

Hitting a pothole on the road in only the wrong way might create a bulge on the tire, a weakened spot that will almost certainly result in an eventual flat tire. But what if that tire could immediately begin reknitting its rubber, strengthening the bulge and preventing it from bursting?

That’s exactly what blood vessels can do after an aneurysm forms, according to new research led by the University of Pittsburgh’s Swanson School of Engineering and in partnership with the Mayo Clinic. Aneurysms are abnormal lumps in artery walls that can cause brain arteries. Ruptured brain aneurysms are fatal in almost 50 percent of cases.

The study, recently published in Experimental Mechanics, is the first to show that there are two phases of wall restructuring after an aneurysm forms, the first beginning right away to reinforce the weakened points.

Imagine stretching a rubber tube in a single direction so that it only needs to be reinforced for loads in that direction. However, in an aneurysm, the forces change to be more like those in a spherical balloon, with forces pulling in multiple directions, making it more vulnerable to bursting. Our study found that blood vessels are capable of adapting after an aneurysm forms. They can restructure their collagen fibers in multiple directions instead of just one, making it better able to handle the new loads without rupturing.”

Anne Robertson, Professor of Mechanical Engineering and Materials Science, Pitt

To see this process up close, the researchers partnered with Simon Watkins at Pitt’s Center for Biologic Imaging, taking advantage of the centre’s state-of-the-art multiphoton microscopes to image the architecture of the fibers inside the aneurysm wall.

“We found that the first phase of restructuring entails laying down an entirely new layer of collagen fibers in 2 directions to better handle the new load, while the next phase involves remodeling existing layers so their fibers lie in two directions,” explained Chao Sang, that was a primary investigator on this study as part of the doctoral dissertation in Pitt’s Department of Mechanical Engineering and Materials Science

“The long-term restructuring is akin to a scar forming after a cut has healed, while this initial phase that we observed can be considered as having a function similar to clotting immediately after the cut–the body’s first reaction to protect itself,” added Robertson, who has a secondary appointment in the Swanson School’s Department of Bioengineering. “Now that we know about this first stage, we can begin to investigate how to market it in patients with aneurysms, and how factors such as age and preexisting conditions affect this ability and may place a patient at higher risk for aneurysm rupture.”