Doctors in New York say they expect former U.S. President Bill Clinton to make a full recovery from a surgical procedure, lasting almost four hours, to drain fluid from his left lung and remove scar tissue. The doctors expect Mr. Clinton to be walking within 24 hours.

Doctors say the fluid and scar tissue are an uncommon complication resulting from the quadruple bypass surgery Mr. Clinton had just six months ago.

Dr. Joshua Sonett performed the surgery at New York Presbyterian Hospital at Columbia University Medical Center by making a small incision in Mr. Clinton's chest. He said Mr. Clinton had lost 25 percent of his lung capacity from the combination of fluid and scar tissue.

"We were quite delighted by the end of the case," said Dr. Sonett. "President Clinton's lung was very healthy, pink appearing, and looked excellent. We expect full functional recovery of the lung."

The doctors say Mr. Clinton will be able to continue the active life he leads in retirement. The day before the surgery, he was raising money for tsunami victims at a golf tournament in Florida, where he expressed optimism about the procedure. 

"There is nothing wrong with me except that I have a fluid build up between my ribs and my lung and it constricts my breathing and I need to fix it over the long run," Mr. Clinton noted.  "But I am otherwise very active and can do fine and they thought it was fine for me to come down here and play golf."

Shortly after the surgery, hospital officials said Mr. Clinton was awake and visited by his wife, New York Senator Hillary Rodham Clinton, and daughter Chelsea. The former U.S. leader is expected to remain in the hospital between three to 10 days. Doctors say it normally takes four to six weeks for full recovery from the procedure.  Well-wishers can write Mr. Clinton at clintonfoundation.org.