Updated

A 15-month-old Afghan boy was breathing on his own Wednesday following surgery to repair a life-threatening heart defect that had been diagnosed by a U.S. military doctor working in a refugee camp.

Surgeons at the Riley Hospital for Children (search) operated on Qudrat Wardak (search) for about six hours Tuesday to move the reversed main blood vessels in his heart into their proper place.

Dr. Mark Turrentine said Tuesday he was pleased and thankful to see Qudrat doing so well after the high-risk operation. The boy was listed in serious but stable condition Wednesday.

"He's doing rather well," hospital spokesman Jon Mills said.

The first 24 to 48 hours after surgery are the most critical as doctors must monitor Qudrat to ensure that his heart was functioning properly, Turrentine said.

"Once he's taking formula and we know he's doing well on his own, he could be released," said Dr. Robert Darragh, a pediatric cardiologist.

The U.S. military flew Qudrat and his father from Afghanistan nearly two weeks ago for the surgery after an Indiana National Guard (search) doctor diagnosed the heart problem during an exam at the camp in the Afghan capital, Kabul.

After Qudrat is discharged, he will need further monitoring for a couple of weeks and then be able to go back to Afghanistan, where he most likely would not need any medication or medical assistance, Darragh said.

Qudrat's condition is called transposition of the great arteries, in which the aorta and pulmonary artery are reversed, sending oxygen-rich blood from the heart to the lungs and oxygen-poor blood into the rest of the body.

The boy, who at 13 pounds weighs about as much as a typical 5-month-old, also suffers from other heart problems, which combine to restrict his blood flow and stunt his development, Riley doctors have said.

Qudrat's father, Hakimgul Wardak, 32, was exhausted after staying up all night Monday with his son and then Tuesday morning carrying him into the operating room.

"He's very overwhelmed and happy after he saw his son in the operating room and doctors told him how super Qudrat was feeling," Wardak's interpreter said.

The surgeons were donating their time to help the boy, and the Rotary Club (search) is covering other costs.

Doctors at Riley who examined Qudrat after he arrived Feb. 25 found his condition was more serious than first thought, and the surgery was postponed while he was treated for respiratory and eye infections.