WASHINGTON (AP)—Sen. Joseph R. Biden Jr. of Delaware was listed in satisfactory condition Sunday after undergoing surgery to correct a burst aneurysm in an artery supplying blood to his brain, a hospital spokesman said.

The 45-year-old senator, who remained in intensive care at Walter Reed Army Medical Center, was “alert and talking to his family and resting comfortably,” said Michael McGinnis, a spokesman for the hospital.

“Senator Biden, following surgery, continues to progress toward recovery,” McGinnis said. “His condition has been updated to satisfactory and his physicians are very pleased with his progress so far.”

Biden, chairman of the Senate Judiciary Committee and a former Democratic presidential contender, had been listed as “seriously ill” following eight hours of surgery Friday.

The aneurysm, which is a sac formed at a weak spot on the artery wall, burst, forcing doctors to proceed with the surgery, McGinnis said. A burst aneurysm, left untreated, could shut off the flow of blood to the brain.

Hospital spokesman Pete Esker said Saturday the aneurysm was within Biden’s cranium, but underneath the brain. The surgery did not involve removal of any brain tissue, the spokesman said.

Pete Smith, an aide to Biden, said the senater was expected to suffer no significant after-effects from the surgery.

Biden was admitted to the hospital early Friday after being transferred from St. Francis Hospital in Wilmington, Del., where he lives.

Biden, a three-term senator, had been complaining for a couple of weeks about what had been diagnosed as a pinched nerve in his neck.

He wore a neck brace two weeks ago during hearings on the proposed Intermediate-range Nuclear Forces treaty with the Soviet Union. However, he was ill and unable to vote last week on the confirmation of Judge Anthony Kennedy to the Supreme Court.

Biden, as chairman of the Senate panel, had led the committee hearings on Kennedy’s nomination to the high court.

Over the last week, Biden felt well enough to fulfill several speaking engagements at colleges on the East Coast.

Last June the senator announced he was a candidate for president, but withdrew from the race in September following disclosures that he had borrowed, without attribution, the campaign rhetoric of a British politician and had exaggerated his academic accomplishments.