Japan's 78-year-old Emperor Akihito underwent successful heart bypass surgery Saturday that should allow him to lead a more active life, AP quoted a palace official as saying. The operation lasted about five hours as expected, and Akihito was being monitored in an intensive care unit at the University of Tokyo Hospital, the official from the Imperial Household Agency said. Akihito was scheduled for the surgery after tests last weekend showed his heart condition had worsened from a year ago. Two of three narrowed coronary arteries were repaired using a blood vessel from another part of his body, said the official, who spoke on condition of anonymity, citing protocol. Japanese media reported doctors intended to use "off-pump" surgery and that the medical team included a specialist in the method, Atsushi Amano from Juntendo University Hospital. By not using an artificial cardiopulmonary machine, "off-pump" surgery is considered easier on a patient.