Intracoronary snaring of the retrograde guidewire: How to overcome extreme takeoff angles in chronic total occlusion percutaneous coronary intervention.

Extreme angulation of coronary artery takeoff represents a challenge for wiring and device advancement in percutaneous coronary intervention (PCI). This anatomic feature is particularly adverse in cases of chronic total occlusion (CTO) of the ostial-proximal segment of the target vessel. In this setting, the retrograde approach can help getting access to the occlusion. However, difficulties might arise at the critical step of wire externalization, due to the need to overcome the extreme ostial angle. Here, we describe a case of successful CTO PCI of the proximal circumflex artery, which presented an extreme angle at its takeoff. Due to inability to perform antegrade wiring of the occlusion, the retrograde approach was undertaken via epicardial collaterals from the right coronary artery. Since conventional attempts at re-entering the antegrade guiding catheter failed due to the aforementioned extreme angle, the retrograde wire was snared in the mid left anterior descending artery, and externalization was performed. This case demonstrates the usefulness of coronary snares in the CTO operator's toolkit and shows how such devices can be used to safely and successfully complete challenging retrograde procedures.