The surgery was performed this morning. The 75-year-old was keeping "well" and will be in the Critical Care Unit (CCU) for the next three days, party sources said.
Ramadoss was arrested on April 30 for trying to stage a protest at Villupuram, defying a ban seeking arrest of culprits behind the April 25 Marakkanam violence.
He was admitted to the hospital as he complained of breathlessness after being released from Tiruchirappalli central prison on May 11 on being granted bail.
Ramadoss was arrested in connection with four other cases also but granted bail in all.
His arrest triggered widespread violence in several parts of the state, leading to the detention of a large number of party workers, including several under the stringent Goondas Act and National Security Act.