Inadvertent distal coronary sinus perforation via a large thebesian vein during angiography

A 57-year-old man with a history of coronary bypass grafting underwent coronary angiography because of stable angina pectoris. During left system angiography with a JL4 angiography catheter, a large localized contrast leak was observed distributed along the epicardial fat pad around the proximal great cardiac vein (GCV) with no proceeding pericardial effusion after an inadvertent forceful injection, which later demonstrated the GCV and coronary sinus (CS) as well (Video 1). The catheter was pulled back from the left ventricular cavity to the aorta, the left main coronary artery was then cannulated, and left system angiography was performed (Video 2). When the images were reexamined carefully, the JL4 catheter was observed to have inadvertently intubated a large thebesian vein endocardially around the anterior mitral annulus (Fig. 1 and 2). A possible explanation for the presence of localized contrast clouding is that the perforation or dissection extended from the thebesian vein branches into the GCV as a result of forceful injection. No complications were observed thereafter.