Human collagen-based pulmonary valve offers new hope for treating childhood heart disease

The scientists’ discovery could help avoid all the complications associated with current surgical methods, particularly those performed on babies with tetralogy of Fallot.

Researchers at Inserm in Bordeaux have developed a pulmonary valve based on human collagen, which could prevent complications when treating heart disease in children. The process has been tested on animals and is so far giving good results, according to a study published in the journal Science Translational Medicine.

Some babies do indeed suffer from a heart defect at birth, called tetralogy of Fallot. This condition affects one in 4,000 newborns. Blood flows poorly between the heart and the lungs, and the baby does not have enough oxygen in the blood. The operation therefore consists of widening the pulmonary passage and reconstructing the valve. To date, doctors use chemically treated animal tissue or synthetic Teflon membranes.

But these two techniques “have major drawbacks”explains Inserm. “First of all, there is a reaction of the immune system, which seeks to reject these foreign bodies. Accompanied by a chronic inflammatory reaction, this phenomenon can also lead to other complications such as thrombosis and calcification.”explain the researchers. Another problem,“Valves made from these materials are conducive to the development of bacterial infections”. Moreover, “They are not designed to accommodate the patient’s growth and changes in morphology over time: this means that as the patient ages, further operations will be necessary to replace the initial valve.”.

Inserm researchers have therefore found a solution by manufacturing a pulmonary valve based on sheets of human collagen, a protein naturally present in the body to support tissues and organs and which has the enormous advantage of not causing rejection, collagen being present in all humans.

“Since collagen does not vary from person to person, these completely biological and chemically undenatured sheets are not considered by the body as foreign bodies to be rejected.”

The valve was successfully tested on a bio-artificial heart “which makes it possible to reproduce the functioning of the human heart and to control heartbeats using pneumatic muscles”, reports Inserm. It was subsequently tested on a sheep. The scientists have “implanted the valve for seven days in an animal model (sheep), performing the same surgical procedures and using the same tools as those used during this type of operation in humans”specifies the research institute which will continue the tests before testing its discovery on humans.

“For the team, the next step is to implant the valve over longer periods (16 weeks, then a year) in animal models, to ensure that it is functional in the long term and that it accompanies the animal’s growth over time. In the longer term still, if the results are conclusive, clinical trials could be considered.”