LDS Church President Ezra Taft Benson was upgraded to serious but stable condition and was showing signs of improvement Monday after undergoing surgery for a second time in four days to remove a blood clot from the left side of his brain.

The 91-year-old leader of The Church of Jesus Christ of Latter-day Saints remained in LDS Hospital's intensive care unit following Sunday's 2 1/2-hour surgery.The surgery began at 2:30 p.m. immediately after LDS Hospital staff, monitoring President Benson, observed symptoms of recurrence, a hospital spokesman said.

During Sunday's surgery, doctors went into the left side of President Benson's head, where last week they had to perform a craniotomy, to drain fluid caused by the larger of the two clots.

Sunday's surgery, which doctors called "a success," consisted of re-draining the clot on the left side of President Benson's head through a surgically-created opening made during Wednesday's operation, LDS Hospital spokesman Tim Madden said.

"A major concern with clots like this is the possibility of recurrence," Madden said. "It's not uncommon, and surgeons suspected that the clots might flame up again. To guard against the possibility of another recurrence, we're keeping him in intensive care for the next few days."

The sudden surgery came as a surprise after President Benson was upgraded to fair condition Saturday. "He was quite responsive yesterday. He was sitting up and visiting with people and even watched a football game on television," Don LeFevre, director of media relations for the LDS Church, said Sunday. "It's a shame something like this had to happen."

The church president and prophet underwent similar surgery Wednesday, one day after a CT scan revealed collections of fluid on both sides of his brain. The clots, 1 to 2 centimeters thick, had "compressed the brain" and President Benson was having difficulty swallowing and was experiencing severe headaches.

Neurosurgeon Bruce F. Sorensen removed two bilateral subdural hematomas (collections of fluid) and inserted drains to remove saline solution used to irrigate the areas where the clots were located.

During a press conference last Wednesday, Sorenson said his main concern was that new clots could accumulate. Several CT scans were planned to monitor clotting.

"The fact he's in critical condition shouldn't really alarm people," Madden said. "It's quite common for a person his age who has just undergone an operation to be listed critical."

President Benson was returned to his room in intensive care at 5 p.m., following the operation. "He's resting right now," Madden said. "He tolerated the surgery extremely well, and for now, his condition seems stable."