Surgeons at Children’s Hospital at Montefiore Medical Center in the Bronx have pulled off a stunning feat: a 27-hour surgery to separate twin brothers Anias and Jadon McDonald, who were joined at the head and are now 13 months old. The intense separation procedure lasted 16 hours by itself,, and that was followed by hours of surgery to rebuild the skulls.

Jadon was finished first, taken out on a stretched at 7:40 a.m. with a beautiful newly haped head, according to a CNN report. He was taken to the pediatric intensive care unit where he got to be with his parents, Nicole and Christian McDonald.

Five hours later, Anias joined them.

Dr. James Goodrich, a leading expert on craniopagus surgery, had completed six such surgeries before, but this was his longest. It is only the 59th carniopagus separation surgery since 1952 worldwide.

The procedure had some major risks, so the parents didn’t take the decision lightly. There was the possibility of brain damage or even death for one or both boys, but not operating had its own risks. About 80 percent of twins die of medical compications by the age of 2 years old when they are joined at the head, and then there are quality of life concerns as it would be extremely difficult for them to live normal lives when connected at the head.

Nicole, the mother, said in a Facebook post: “Dr Goodrich and his team just left. He walked in the room and plopped in the arm chair by the door. After 16 straight hours of surgery, he still had his sense of humor. “Well, we did it,” he said. But we are definitely not out of the woods by any means. Straight from the surgeon’s mouth, “These boys were right there on top” (as the hardest case he’s ever encountered). The amount of vasculature involved was much more complex than all of those high-tech imaging systems could show. There was a point where Dr Goodrich debated stopping the whole procedure because it was just too risky but an opening presented itself and they went for it and it ended up being the right call. The boys ended up sharing a 5 x 7 cm area of brain tissue with no definite plane for dissection…so Dr Goodrich had to make the call and the final cut based on his instinct.”