Emperor Akihito underwent a procedure Wednesday to have fluid removed from his chest that had accumulated since undergoing heart bypass surgery last month, the Imperial Household Agency said.

Officials said the treatment conducted at the Imperial Household Hospital was completed without any trouble and a considerable amount of fluid was removed.

The 78-year-old Emperor, who was discharged Sunday from University of Tokyo Hospital, where he had heart surgery Feb. 18, arrived at the Imperial Household Hospital along with Empress Michiko and underwent suction to drain the buildup of fluid, which had recently increased.

Since being discharged from the university hospital, the Emperor had not been eating as much as expected and was experiencing shortness of breath, not just when walking up and down stairs, according to the agency.

A team of doctors treating the Emperor had said earlier that fluid buildup is a common condition following coronary artery surgery.

The Emperor is hoping to attend a memorial service Sunday in Tokyo to commemorate victims of the March 11 earthquake and tsunami, according to Imperial Household Agency officials.