Right coronary artery anatomy: Chronic total occlusion interventionist’s perspective

Chronic total occlusion (CTO) intervention success has been improving with the evolution of newer devices and increasing operator expertise. In the recanalization of CTO, apart from CTO anatomy, occluded artery anatomy on either side of the CTO and collateral anatomy play a significant role in planning interventional strategy. Occluded artery anatomy affects the support provided by the guide for antegrade wiring, retrograde gear reach to the distal cap, selection of the site, and the type of reverse controlled antegrade and retrograde tracking and externalization. The right coronary artery (RCA) is the most common host for CTOs and shows many more variations in the course than other coronaries, posing specific challenges to interventionists while planning wiring strategies. The collateral entry pattern into RCA affects the retrograde gear reachability to the distal cap, steerability of wire, and support provided to retrograde wire escalation. Overall, some unique challenges interventionists face while treating RCA CTOs are linked to frequent anatomical variations in the origin from the aorta, tortuosity in the atrioventricular groove course, site of patent ductus arteriosus origin, and collateralization pattern both ipsilateral and contralateral. This manuscript describes anatomical variations of RCA and its collaterals, which interventionists should be mindful of while planning the wiring strategy and other procedural steps.