TOKYO - Japanese Emperor Akihito's heart bypass surgery operated on Saturday was successful, according to the Imperial Household Agency.

Japanese Emperor Akihito is greeted by doctors upon his arrival at the entrance of the University of Tokyo Hospital in Tokyo Feb 17, 2012. [Photo/Agencies]

The coronary-artery bypass surgery was aimed to improve the life quality for the 78-year-old emperor, according to his doctors.

The surgery was conducted by a team of doctors from the University of Tokyo Hospital and Juntendo University Hospital. The emperor entered the hospital on Friday morning and is expected to be able to leave hospital in two weeks.

The emperor was earlier diagnosed with angina after an angiogram performed last Saturday.