DMK president M Karunanidhi today underwent a procedure at a private hospital here in which a tracheostomy tube was replaced by a new one.
The 94-year-old Karunanidhi, who was admitted this morning, was later discharged following completion of the procedure, Cauvery Hospital here said.
Members of the DMK patriarch's family were present during the hospitalisation.
Karunanidhi fell ill in October 2016 due to a drug-induced allergy.
The veteran leader was admitted to the hospital for "optimisation of nutrition and hydration" in the first week of December that year and later, due to a throat and lung infection.
He had undergone tracheostomy, a procedure to optimise breathing.