Angioscopy is a medical technique for visualizing the interior of blood vessels. In this technique, a flexible fiberoptic catheter inserted directly into an artery. It can be helpful in diagnosing e.g. arterial embolism. Angioscopy is also used as an adjunctive procedure during vascular bypass to visualize valves within venous conduits.
Coronary artery angioscopy, which first was used to reveal the presence of a blood clot in the coronary arteries of patients with unstable angina and myocardial infarction, is now widely used in catherization laboratories to visualize stents.