Retrograde approach for chronic total occlusion percutaneous revascularization

The retrograde approach via collateral chan­ nels in coronary angioplasty for chronic total occlusion (CTO) can improve the recanaliza­ tion success rate. Most interventionalists will meet a few cases where the retrograde approach might provide unequaled advantages, but many are held back from choosing the retrograde approach owing to a lack of proper equipment and expertise. The retrograde approach requires an intercoronary channel between the occluded artery and another patent coronary artery, which enables the distal CTO site to be reached with retrograde approach. The intercoronary channel may be a septal collateral, an epicardial collateral or a bypass graft. Although in principle a retrograde CTO crossing is easier than an anterograde crossing because the distal cap is usually softer than the proximal cap [1], a proportion of CTOs remain very difficult to cross even with the retrograde approach. The length, duration and the presence of calcium determines the difficulty in crossing the CTO even with the retrograde approach, and among these, the distribution of calcification is one of the most important issues. The presence of calcium on fluoroscopy usually indicates a long and difficult procedure. This means that mul­ tislice computed tomography (MSCT) coronary angiography could be very helpful for under­ standing the course of the vessel when coro­ nary vessel reconstruction is performed, similar to the angiographic views, especially in very long occluded segments. However, the operator should not feel discouraged in the presence of some long and difficult­looking lesions. If a good Coronary chronic total occlusion represents the most challenging lesion subset for interventional cardiology. Among other new techniques and developments, the retrograde approach via collateral channels in coronary angioplasty for chronic total occlusion can improve recanalization success rates. Most interventionalists will meet few cases where the retrograde approach might provide unequaled advantages, yet many are held back from choosing the retrograde approach owing to a lack of proper equipment and expertise. This article provides a detailed description of all techniques used to traverse the collateral channels and to cross the chronic total occlusion by the retrograde approach. It also illustrates the difficulties in collateral channel crossing using different examples to provide a basic guide for case selection purposes.