PLAINS, Ga. -- Former U.S. President Jimmy Carter said Monday he was "deathly afraid" as his 90-year-old wife underwent surgery over the weekend.

Rosalynn Carter was recovering at Emory University Hospital in Atlanta after surgeons removed scar tissue from a portion of her small intestine early Sunday. Meanwhile, her husband of 71 years kept his scheduled appearance Monday at a President's Day even at the Jimmy Carter National Historic Site in his hometown of Plains.

Jimmy Carter addressed concerns about his wife's health and surgery in remarks to several hundred people attending the holiday event. The Atlanta Journal-Constitution reported Carter said his wife had suffered problems for years that appear to have been caused by scar tissue from an operation she had long ago.

"Saturday night they operated and found the scar tissue from the old operation about 50 years ago had strangled almost 2 feet of her small intestine," Carter told the crowd.

He said doctors "didn't give me a lot of hope" until the operation concluded hours later.

"I was deathly afraid," Carter said. "I prayed for three hours."

He said a doctor finally came to him at about 5 a.m. Sunday morning and "told me she was going to be OK."

The Carter Center said in a statement Sunday the surgery was successful. It said Rosalynn Carter was expected to remain hospitalized for several days as she rests and recovers.

The former first lady married Jimmy Carter on July 7, 1946. She emerged as a driving force for mental health during his presidential administration and after he left office.

Monday marked Carter's fourth straight year appearing at the President's Day event in Plains. He said it was the first time that his wife did not accompany him.