The first baby to undergo a partial heart transplant
will hopefully
be spared repeated heart surgeries as the implanted tissue grows with him, a result never before seen in humans.
Surgeons made history in 2022 when they sutured heart valves and vessels removed from
a donor baby
into the heart of transplant recipient Owen Monroe when
he was just 18 days old.
This technique of salvaging native heart tissue and only using living donor tissue to replace defective parts has never been tested in humans before,
Science Alert reports.
The lead surgeon, Joseph Turek of Duke University, had only performed the procedure on
five piglets.
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.
Owen's heart tissue implants are growing at a rate similar to heart tissue from healthy babies (dotted line) (Turek et al., JAMA),
Owen's heart function is
"excellent
," and he is reaching the developmental milestones of a normal one-year-old, such as
playing, crawling and standing,
the researchers reported in
JAMA.
"This publication is proof that this technology works, this idea works and can be used to help other children," Turek says.
An almost miraculous operation
Owen's parents, Nick and Tayler Monroe, consented to the surgery after learning their baby
had a serious heart defect
known as truncus arteriosus, where a canal leading from the heart fails to separate during development, fusing two vessels. major blood vessels in a way that deprives the baby of oxygen,
Science Alert says.
This condition affects about
250 babies
in the US each year.
Typically, babies with truncus arteriosus receive a whole heart transplant or are treated with frozen tissue from
cadaver hearts.
Donor hearts transplanted into babies will grow with the child, but often become dysfunctional over time.
As a result, about half of children who receive a heart transplant
will die by the age of 20.
Owen with his parents right after he was born (Duke's Health).
To prevent transplanted hearts from being rejected by the immune system, recipients are given drugs that suppress the immune system, preventing the body from fighting not only heart tissue but also cancer and infections, says Science Alert
. .
It is the donor heart muscle, rather than the valves and vessels, that the body tends to reject as foreign.
Because baby Owen only received a partial vessel and valve transplant, he only needed a half dose of one of these immunosuppressive medications.
Babies treated for truncus arteriosus with frozen cadaver tissue need surgery every few years to replace outgrown grafts,
Science Alert reports.
As a result of these risky surgeries, this treatment carries a 50 percent mortality risk while they are still in childhood.
will have a normal life
Baby Owen was on the list for a heart transplant, but his parents knew he was unlikely to survive the six months or so it would take to
find a donor,
Science Alert says
.
A few days after he was born, Owen was already in heart failure and his heart was too weak to receive emergency treatment, such as a cardiopulmonary bypass called ECMO.
The baby underwent a partial heart transplant (Turek et al., JAMA).
Part of the heart tissue was removed and tissue from a heart donor was implanted (Turek et al., JAMA).
"Once they told us the situation and that we didn't have time to wait for a heart and that he was basically in heart failure from the beginning, there really weren't many options," Tayler Monroe said.
"If something happened, we would just resuscitate him and hope for the best, which is really difficult and scary to hear."
Fortunately, Owen's patched heart now pumps normally and
is "expected to last a lifetime,"
researchers report.
The article was published in
JAMA
.
See also
See also
A pilot heard "cries for help" from the hold and made an emergency landing
See also
See also
They filmed a squid from "another planet" at a depth of 4,000 meters
See also
See also
They detected a mysterious radio signal coming from the heart of the Milky Way
GML