Milagros Martinez said Monday her son, Javier Acosta, 11, had the operation Oct. 13, ABC News reported. She said she wanted to wait to make any public announcement until the outcome was clear.
"Although his prognosis is good, Javier is still in the hospital adjusting to his new lungs," Martinez said. "We are deeply grateful to the donor, the donor family and the wonderful doctors and staff at Children's Hospital of Philadelphia. We offer our sincere thanks to those who helped us and supported us and prayed for us. "
Regulations that effectively barred children under the age of 12 from receiving adult lungs became an issue earlier this year when the family of Sarah Murnaghan, also a patient at Children's, challenged them. Javier's family joined the battle. The regulation put children at the bottom of transplant lists for adult lungs, meaning they would only become recipients if no adults in the area needed transplants.
Adult lungs are more likely to be available for transplant, but experts say children in many cases are not suitable recipients.
Chad Holtzman, a lawyer who represented both children, won temporary restraining orders barring the regulation from being enforced in their cases. Sarah received a double transplant months ago.
The Organ Transplantation and Procurement Network decided in June to keep the regulation but to allow exceptions.
Notable deaths of 2014 [PHOTOS]