Sharon's Breathing Tube Replaced

(CBS/AP)  Israeli Prime Minister Ariel Sharon had surgery overnight to replace his breathing tube.

CBS News correspondent Robert Berger reports doctors at Hadassah Hospital in Jerusalem replaced the 77-year-old Israel leader's breathing tube due to a technical problem which developed following a tracheotomy on Sunday.

Sharon is in critical but stable condition, but even though he is off sedation, efforts to bring him out of a coma have failed. Sharon has been in a coma since suffering a massive stroke on January 4th, and experts say serious brain damage is likely.

The hospital said Wednesday that there no problems in surgery as the breathing tube was replaced, and Sharon is in critical but stable condition.

Sharon was originally put into a coma deliberately by doctors, a technique that is sometimes used to give the brain a chance to heal. He was taken off those drugs last week, however, and has yet to emerge from the coma.

Outside experts have said his failure to regain consciousness in recent days bodes poorly for his recovery.

After the stroke, Sharon underwent three operations to stop the bleeding in his brain. Medical officials said last week he showed some movement on both sides of his body in response to pain stimuli, but he has shown no signs of improvement since then.

Sharon briefly opened his eyes Monday in response to a recording of his grandson's voice, relatives told doctors, but hospital officials warned the movement may have been an involuntary twitch, and there were no signs that the comatose Israeli leader was any closer to regaining consciousness.