Veteran filmmaker Rakesh Roshan underwent a surgery after his carotid arteries were found 75% blocked. Carotid arteries are blood vessels that supply blood to brain, face and neck. In case of blockage, reduced blood flow can damage brain tissue. "Blockage is typically due to atherosclerosis, a condition where fatty deposits and cholesterol accumulate in…artery walls," said Dr Sanjeeva Kumar Gupta.