What is an ostial lesion?

• A. Blockages associated with origin of aorta or main artery
• B. Blockage near the end of a long vessel
• C. Blockage of a side branch ostium
• D. Blockage in the middle of a vessel

Answer: (A)

An ostial lesion is a blockage located at the opening where a vessel originates—the ostium. In the coronary arteries, this means disease right at the origin from the aorta, at the coronary ostium. That entrance location is what defines an ostial lesion, and it explains why these lesions are treated with particular attention to ensuring the stent fully covers the ostium without protruding into the aorta and without leaving diseased tissue at the entrance. Distal or mid-vessel blockages are not at the opening, and a blockage at a side-branch ostium is also at an ostial location, but the classic and most clinically emphasized ostial lesion is at the origin of the main coronary artery from the aorta.