Prime Minister Ariel Sharon on Wednesday underwent surgery to reattach a piece of his skull, a day after the procedure was delayed because of a respiratory infection, hospital officials said. "The surgery that Prime Minister Ariel Sharon was supposed to have yesterday took place today and ended successfully a short while ago," Hadassah Hospital said in a statement. It said Sharon was taken back to his room in the intensive care unit, where he has been hospitalized since suffering a massive stroke on Jan. 4. Doctors removed the piece of skull to operate on his brain after the stroke. Wednesday's surgery was the eighth operation on the prime minister since he fell ill.