Sen. Mark Kirk (R-Ill.) remains in “serious but stable” condition in a Chicago-area hospital after undergoing a second procedure Wednesday night to relieve additional swelling associated with a stroke he suffered last weekend.

A statement from Northwestern Memorial Hospital made on behalf of Kirk’s neurosurgeon Richard Fessler indicated that the “common procedure” will likely not have an effect on his mental or physical prognosis.

“Upon examination this morning, the Senator was alert, responsive and gave us the thumbs up on request,” Fessler said in the statement.

The procedure involved removing two small pieces of tissue impacted and rendered non-functional by Kirk’s stroke, and “was completed successfully and without complication,” according to the hospital.

Kirk, 52, suffered a stroke over the weekend as a result of a torn carotid artery. He underwent a first surgery Monday in which doctors temporarily removed a 4-inch-by-8-inch piece of his skull to relieve the pressure caused by brain swelling.

On Tuesday, doctors indicated the Illinois Republican likely would spend another week in the intensive care unit. The hospital’s statement did not say whether the Senator’s second procedure affects that timeline.