Researchers said that the first child to undergo a partial heart transplant may not witness repeated heart surgeries as the transplanted tissue grows with him, in an unprecedented result in humans.
Surgeons made history in 2022 when they sewed heart valves and vessels taken from a child donor into the heart of organ transplant recipient Owen Munro, when he was just 18 days old.
This technique of saving the original heart tissue and using only living donor tissue to replace the defective parts has not been tried in humans previously. The lead surgeon, Joseph Turek of Duke University, had previously performed the procedure on only five pigs.
Now, more than a year later, baby Owen's heart has grown from the size of a strawberry to the size of an apricot, and the donor tissue has grown with it.
The researchers reported that Owen's heart function is "excellent", and he is achieving developmental milestones for a normal one-year-old child, such as playing, crawling and standing.
Owen's parents, Nick and Tyler Monroe, agreed to the surgery after learning that their child had a serious heart defect known as truncus arteriosus, in which the duct leaving the heart fails to separate during growth, resulting in two major blood vessels merging in a way that deprives the child of oxygen. .
Typically, infants with truncus arteriosus are either given a full heart transplant, or are treated using frozen tissue from cadaver hearts. Hearts transplanted into infants will grow with the child, but they often become dysfunctional over time. As a result, about half of children who undergo a heart transplant will die by age 20.
To prevent transplanted hearts from being rejected by the immune system, recipients are given medications that suppress the immune system, preventing the body from fighting not only heart tissue, but also cancer and infections.
The body tends to reject the donor's heart muscle, but not the valves and vessels. Because baby Owen only had a partial blood vessel and valve transplant, he only needs half a dose of one of these immunosuppressive drugs.
Infants treated for truncus arteriosus using frozen cadaver tissue need surgery every few years. As a result of these risky surgeries, this treatment carries a 50% risk of death.
Fortunately, Owen's heart is now pumping normally and is expected to continue for life, researchers report.
The research paper was published in JAMA.
Source: ScienceAlert - Publication date: 29/01/2024 - https://r.rtarabic.com/wvf6