(CNN)Brooke Kilburn's doctors told her there was a 5% chance she'd ever meet her unborn son.
A 2-year-old born without a larynx or airway is the recipient of a historic voice box reconstruction
But Cooper survived his birth -- and then spent 324 days in the neonatal intensive care unit.
At 2 years old, her son's beaten the odds again, this time as the recipient of the world's first successful total voice box reconstruction.
Doctors at Le Bonheur Children's Hospital in Memphis, Tennessee, performed the procedure in February, the hospital said in a statement.
Cooper was diagnosed with congenital high airway obstruction syndrome, a rare illness with an extremely high mortality rate, while he was still in the womb. Because of the condition, he was born without a larynx or an airway, said Kilburn, of Adamsville, Tennessee.
Since birth, he's breathed through a tracheostomy, a hole in his throat that extends into his windpipe.
His team of physicians at Le Bonheur decided that when Cooper turned 2, they'd aim to help him breathe without it.
"We planned for this surgery from day one of Cooper's life," Dr. Jerome Thompson, an otolaryngologist who treated Cooper, said in a statement.
On February 27, years of planning came to fruition when doctors performed the four-hour surgery. They built Cooper's voice box using two of his ribs, according to the hospital.
It was Cooper's eighth surgery in two years, the hospital said.
"It was a nerve-wracking surgery because there were so many unknowns," Kilburn said. "We had no idea as to what they were actually going to find when they got in there."
In May, he made a sound for the first time, according to the hospital. It'll take a few more years to wean him off the tracheostomy so he can breathe on his own completely, she said, but the surgery gave him a great start.
Cooper will continue to see surgeons every two weeks for new procedures to mold his new airway. Kilburn said she's hoping that by December, the team will finally get the shape they want and let him explore his new voice.
"Cooper is a miracle," she said. "There's just no other way to look at it."