The first child in the world to have a double hand transplant is able to write, feed and dress himself independently 18 months after the operation at a US hospital, doctors have said.
As a toddler, Zion Harvey lost his hands and feet to a life-threatening sepsis infection that led to multiple organ failure.
He received his two donor hands aged eight in a groundbreaking procedure that doctors have declared a success following months of complications and rehabilitation.
Dr Sandra Amaral, from the Children’s Hospital of Philadelphia, where Zion was treated, said he was continuing to improve his hand function through daily therapy sessions.
“Our study shows that hand transplant surgery is possible when carefully managed and supported by a team of surgeons, transplant specialists, occupational therapists, rehabilitation teams, social workers and psychologists,” she said.
“While functional outcomes are positive and the boy is benefitting from his transplant, this surgery has been very demanding for this child and his family.”
Doctors managed to reverse the eight rejections, two of which were serious, using drugs that suppress the immune system.
Zion was already taking these immunosuppressive drugs because he had received one of his mother’s kidneys in a transplant aged four – the reason he was chosen for the hand surgery, the report said.
Four medical teams carried out the transplant, a complex procedure which took nearly 11 hours, in July 2015.
Just days later, Zion was able to move his new fingers and began rehabilitation therapy through video games and simple exercises using finger lights and puppets.
Regular brain imaging after the transplant showed that the boy’s brain developed new pathways to control the transplanted hands and experience touch sensations from them.
By eight months, Zion could use scissors and crayons, and could swing a baseball bat using both hands after one year.
The doctors said in future it was important to also consider the effect of similar surgery on children who have not previously received immune system suppressing drugs, as they would likely need the same medication to control rejections of the hands.
“There is also long term risk of chronic rejection of the hands with subsequent indications for amputation,” they wrote.
Zion is still taking four different immunosuppressive drugs, including one steroid which can impact growth and bone health, but researchers hope to reduce his dosage when possible.
The report also cast doubts over the use of a similar procedure for leg and foot transplants, as “children and adults function very well with lower extremity prosthetics” which already allow for close-to-natural movements.
By contrast, arms and hands, and their sensations, “play particularly important roles in connecting socially and physically with others and the environment (ie, gestures, self esteem, and touch)”, said the report.
Other medical initiatives to help child amputees include bionic hands, which could be offered on the NHS after a new six-month trial is completed.
Chris King, the first person in the UK to have a double hand transplant, earlier this year picked up a pen and wrote a letter to his surgeon to thank him for performing the life-changing operation.
The 57-year-old said he had been getting on “fantastically” since undergoing the pioneering surgery in July 2016.
He lost both his hands, apart from the thumbs, in an accident involving a metal pressing machine at his workplace in Doncaster four years ago. The accident almost killed him but doctors were able to save enough tissue to make a transplant possible.
He was treated by consultant plastic surgeon Professor Simon Kay, who has performed the three hand transplants that have taken place in the UK to date.
The first patient, Mark Cahill, had a single hand replaced while the third, unnamed, patient had a double transplant.