Doctors inserted a feeding tube in Israeli Prime Minister Ariel Sharon's stomach on Wednesday, according to a statement from Jerusalem's Hadassah Hospital, where he is being treated for a massive stroke.

Sharon, 77, has been in a coma since he suffered a stroke on Jan. 4. Long-term care specialists and a U.S. authority on comatose patients have examined the Israeli leader in recent days. Experts say his chances of regaining consciousness or a meaningful level of activity are slim.

"Tonight Prime Minister Ariel Sharon underwent a gastrostomy, a process in which a tube is inserted into the stomach for feeding," the statement said. "The procedure was carried out under anesthetic and was successful. The prime minister's condition continues to be critical and stable."