WASHINGTON • The first child in the world to undergo a double hand transplant is now able to write, feed and dress himself, doctors said, declaring the ground-breaking operation a success after 18 months.

A report in The Lancet Child & Adolescent Health journal on Tuesday provides the first official medical update on 10-year-old Zion Harvey, who underwent surgery to replace both hands in July 2015.

"Eighteen months after the surgery, the child is more independent and able to complete day-to- day activities," said Dr Sandra Amaral of Children's Hospital of Philadelphia, where the operation took place. He continues to have daily therapy, she added.

Zion had his hands and legs below the knee amputated at the age of two following a sepsis infection. His kidneys also failed. At the age of four, after two years of dialysis, he had a kidney transplant using a kidney donated by his mother.

He was already receiving drugs to suppress any immune reaction to his kidney, which was a key factor in his selection for the 10-plus-hour hand transplant surgery. Immunosuppressive drugs, which carry risks, including diabetes, cancer and infections, must be taken continuously to prevent a patient's body from rejecting the transplant.

The child has "undergone eight rejections of the hands, including serious episodes during the fourth and seventh months of his transplant", said the report.

"All of these were reversed with immunosuppression drugs without impacting the function of the child's hands." Zion continues to take four such drugs and a steroid.

Before the double hand transplant, he had "limited ability to dress, feed and wash himself through adapted processes, using his residual limbs or specialist equipment", said the report.

Zion's mother hopes he would one day be able to brush his teeth and cut up his own food.

Zion, for his part, wants to climb monkey bars and grip a baseball bat properly.

Within days of the surgery, he discovered he could move his fingers, using the ligaments from his residual limbs. "Regrowth of the nerves meant that he could move the transplanted hand muscles and feel touch within around six months, when he also became able to feed himself and grasp a pen to write," said the report.

Eight months after the operation, Zion was using scissors and drawing with crayons. Within a year, he could swing a baseball bat using both hands. He also threw out the first pitch at a Baltimore Orioles game last August.

Regular meetings with a psychologist and a social worker were part of the recovery process, aimed at helping him cope with his new hands. Scans have shown that his brain is adapting to the new hands, developing new pathways to control movement and feel sensations.

Researchers have cautioned that more study is needed before hand transplants in children become widespread.

"The world's first double hand transplant in a child has been successful under carefully considered circumstances," said the report.

The first successful hand transplant in an adult was completed in 1998.

AGENCE FRANCE-PRESSE