Bio-science veins may make coronary bypass, kidney surgery more efficient

Bio-science veins may make coronary bypass, kidney surgery more efficient

Engineered vascular grafts could be useful alternative to synthetically-produced veins used during heart bypass surgery and kidney dialysis rectification. Scientists in the United States have successfully grown human veins in eight to ten weeks that lessen the chances of clotting, infection or obstruction when compared to man-made, synthetic alternatives.

Duke University, East Carolina University and Yale University combined on the research which has gotten notice around the globe.

Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, said:

"Not everyone is well enough to have a vein taken from another part of their body during heart surgery, so using synthetic veins can become an important part of a patient's treatment. However, sometimes even synthetic veins aren't suitable. This study shows that bioengineering can be used to create a novel type of vascular graft that has the potential to improve outcomes for patients. We look forward to the results of clinical trials designed to test this."

Since the British Heart foundation in 1961, an estimated 100,000 people in the UK had heart failure. But an ageing population and the fact that more people now survive heart attacks mean more than 750,000 people now live with the condition and even higher numbers are expected in future in the UK. Around 400,000 coronary bypass procedures are performed annually in the US, says the American Heart Association. Arteries can become clogged over time by the buildup of fatty plaque. Bypass surgery improves the blood flow to the heart with a new route, or "bypass," around a section of clogged or diseased artery.

The surgery involves sewing a section of vein from the leg or artery from the chest or another part of the body to bypass a part of the diseased coronary artery. This creates a new route for blood to flow, so that the heart muscle will get the oxygen-rich blood it needs to work properly.

During bypass surgery, the breastbone (sternum) is divided, the heart is stopped, and blood is sent through a heart-lung machine. Unlike other forms of heart surgery, the chambers of the heart are not opened during the operation.

Published in the journal of Science Translational Medicine one of the American study's authors Dr. Alan Kypson of the Brody School of Medicine at East Carolina University states:

"These can be made ahead of time and then are ready to go whenever they are needed. Currently, grafting using the patient's own veins remains the gold standard. But, harvesting a vein from the patient's leg can lead to complications, and for patients who don't have suitable veins, the bio-engineered veins could serve as an important new way to provide a coronary bypass."

The veins are sterile, so they are not at risk of being rejected by the patients' immune system and can be made in a variety of sizes for use in different operations.

Clinical trials in humans are expected to begin soon, according to a spokeswoman from Humacyte, a regenerative medicine company based in North Carolina that also contributed to the study and funded the research.

The first population to benefit from these bioengineered vessels would probably be kidney failure patients who need to undergo dialysis, in which the blood is cleansed every few days. Dialysis needs fast blood flow to work well, so a patient's best option is surgery to join a large artery directly to a vein, creating a circulatory shortcut that provides an area of surging blood and facilitates dialysis. But many patients have vessels unfit for that surgery or the surgery does not succeed, so they often get implanted with a synthetic vessel to join an artery and vein. Both operations, typically done in an arm, carry risks of infection and clogging from a buildup of cells.

Sources: British Heart Foundation and Duke University School of Medicine

Blood Vessels, part 1 - Form and Function: Crash Course A&P #27 (Video Medical And Professional 2020).

Section Issues On Medicine: Cardiology