Further surgery on Sen. Mark Kirk (R-Highland Park) was successful late Wednesday at Northwestern Memorial Hospital, according to a statement by Dr. Richard Fessler, the neurosurgeon who has been treating the senator.

After examining Kirk today after Wednesday’s procedure, Fessler was pleased with the senator’s condition. “Upon examination this morning, the Senator was alert, responsive and gave us the thumbs up on request,” Fessler said.

The operation created more space around Kirk’s brain to prepare the senator for expected further swelling of the brain, according to Fessler. There were no complications. Kirk remains in serious but stable condition.

“We performed a common surgical procedure to create more space around the senator's brain in order to accommodate the expected peaking of swelling,” Fessler said. “The procedure removed two small pieces of tissue previously destroyed and rendered non-functional by the Senator's stroke.”

Fessler stressed there has been no change in Kirk’s neurological or physical prognosis. He does not think the additional operation will make a difference. “The procedure is unlikely to have any impact on his physical or neurological prognosis,” he said.

On Friday Kirk will receive a visit from Sen. Joe Manchin (D-WV), according to a story in The Hill. Kirk and Manchin, who entered the Senate about the same time, have been regular lunch partners. They had planned to sit together at the State of the Union address Tuesday. Manchin left the seat open to honor Kirk.

Kirk checked himself into Lake Forest Hospital Saturday, where doctors discovered a carotid artery dissection in the right side of his neck, according to a release issued Monday by Kirk’s office. He was transferred to Northwestern Memorial Hospital where further tests revealed that he had suffered an ischemic stroke.