Channel Tracking Guidewire and Technique for Retrograde Approach

Evaluation of the collateral circulation is critical for determining the feasibility of the retrograde approach. When assessing collateral channels it is of paramount importance to take time and review the previous angiogram carefully, for multiple potential collateral pathways, as the predominant collateral may change over time prior to the procedure. Careful review of collaterals prior to the procedure can reduce contrast and radiation dose as well as the duration of the procedure.Retrograde access to the distal vessel can be achieved via septal collaterals, epicardial collaterals (atrial channel), or (patent or occluded) coronary bypass grafts. Generally septals are used more often 65–70% of cases, epicardial 15–20% of cases, atrial 8–10% of cases, and graft 5–8% of cases. In order to identify the best collateral collateral size, tortuosity, bifurcations angle of entry to and exit from the collateral, and distance from the collateral exit to the distal cap should be taken into consideration. Among these parameters the most important predictor of successful guidewire tracking and device crossing is lack of tortuosity, followed by size [1, 2]. The size of the collaterals is often assessed using the Werner classification (CC0: no continuous connection; CC1: threadlike connection; CC2: side branch-like connection) [3].