In 2015, 8-year-old Maryland resident Zion Harvey underwent a harrowing 10-hour double hand transplantation surgery involving a 40 -person team at the Children's Hospital of Philadelphia to replace limbs lost due to a life-threatening sepsis infection. When he was two years old, his hands and feet were amputated and his mother Pattie Ray had to donate a kidney to him because of the infection. 

Now, two years later, and after a series of intense rehab sessions, the 10-year-old has gained considerable control over his new hands. He can write, grip a baseball bat and be more independent than before.

A new report published in the journal The Lancet Child & Adolescent Health on Tuesday, July 18 by surgeons Dr. L. Scott Levin, Dr. Sandra Amaral, and 28 other doctors documented the success of Zion's surgery. It only documents the first 18 months after the procedure but it mentions Zion's newfound independence that gives them hope that others can benefit from the surgery like Zion did. 

"Most of his functional outcomes or progress have been really related to doing things more efficiently and effectively," Amaral told CNN. "A few new things that he can do: zip his pants, rip open a granola bar by himself and manipulate it to eat it."

However, the road was long and not always easy. According to The Washington Post, Zion's body has attempted to reject his new hands eight times. There were some “serious episodes” four and seven months after the transplant, per the report. 

After a year with his new hands, Zion said in This Is Zion: One Year Later film released by the children's hospital that he could do simple tasks without the assistance of others. “Now I can get myself dressed without anybody helping me," he said in 2016. "Now, I can get a snack out the refrigerator without anybody helping me. I can heat up a sandwich and a piece of pizza all by myself. So it feels like I'm there already.”

Watch Zion's progress below.