Two senior neurosurgeons from Dan region hospitals have examined Prime Minister Ariel Sharon, who remains in a coma at Hadassah-University Hospital in Jerusalem's Ein Kerem. The physicians are considering an operation next week to reattach the quarter of his skull that was removed during brain operations nearly three months ago. The operation, to be performed for esthetic purposes, would be part of preparations to move him to a long-term care institution. Prof. Moshe Hadani of Sheba Medical Center in Tel Hashomer and Prof. Zvi Rappaport of the Rabin Medical Center in Petah Tikva examined Sharon on Wednesday. The PM's doctors and family have not yet decided when and where to transfer him. Meanwhile, the inevitable changing of the guard inside the Prime Minister's Office has begun. The office's director-general, Ilan Cohen, has told Acting Prime Minister Ehud Olmert that he will be leaving his position at the beginning of May. Cohen will be replaced by Ra'anan Dinur, a long-time Olmert confidant who served as his director-general at the Ministry of Industry and Trade, and before that as his director-general when Olmert was mayor of Jerusalem. Cohen was a key player in the team Sharon put together to deal with the settlers evacuated from Gaza. Olmert, according to a statement released by his office, thanked Cohen for his service and asked him to continue to act as an advisor on special projects. Cohen became director-general in May 2004, replacing Avigdor Yitzhaki, who was elected as a Kadima MK Tuesday. Other key appointments Olmert is expected to make in the next few weeks include: attorney Yoram Turbowicz as his chief of staff; confidant Ovad Yehezkel as cabinet secretary; long-time advisor Shula Zaken as bureau chief; and his spokesman of nearly 20 years, Haggai Elias, as one of his communications advisers.