NEW YORK (AP) – Former President Bill Clinton, who underwent quadruple bypass surgery in September, will undergo a medical procedure this week to remove fluid and scar tissue from his left chest, his office announced yesterday.

The procedure will take place tomorrow at New York-Presbyterian Hospital/Columbia University Medical Centre. Clinton is expected to remain in the hospital for three to 10 days, his office said in a statement.

Clinton was proceeding with his schedule in Washington yesterday. He smiled and waved to reporters as he entered the State Department for meetings, but did not make any comment. He planned to be at a White House event later in the day, according to his spokesman, Jim Kennedy.

The procedure, known as a decortication, will remove scar tissue that has developed as a result of fluid build-up and inflammation, causing compression and collapse of the lower lobe of the left lung, his office said. The surgery will be done either through a small incision or with a video-assisted thoracoscope inserted between ribs.

Clinton’s problem is a relatively rare complication of his surgery, where inflammation of the lining of the heart develops and fluid builds around it or in the lungs, said Dr John LaRosa, president of the State University of New York Health Science Centre in Brooklyn. It doesn’t signal anything ominous about the former president’s outlook, he said.

The statement said Clinton is expected to resume his work without limitations.

Clinton, 58, had been quite active since his September 6 heart surgery. He underwent quadruple coronary artery bypass surgery last fall after suffering chest pains and shortness of breath.