The Rev. Billy Graham was listed in fair condition Monday at Mission Hospitals, where he continued to recover from an apparently successful operation last Wednesday to replace the valve in his brain shunt.

The 89-year-old minister underwent the surgery to combat the effects of hydrocephalus, a buildup of fluid within the brain. The condition’s symptoms are similar to Parkinson’s disease.

The shunt, which was implanted in 2000, drains fluid from his brain into his abdomen, where the body absorbs it.