Tamil Nadu Chief Minister, M karunanidhi underwent a minimal invasive surgery for back pain on wednesday. Top spine surgeon Dr Arvind Jaiswal in AIIMS who lead the surgery said that the three hour operation was a success and that the CM was doing good.  "All his parameters are absolutely normal and he is shifted to the Intensive Care Unit", the doctor said. Dr S S K Marthandam with his 14 member team of doctors who are monitoring the CM's health said that the CM should remain in ICU for atleast 48 hours.