Stenting of bifurcation lesions: a rational approach

The occurrence of stenosis in or next to coronary bifurcations is relatively frequent and generally underestimated. In our experience, such lesions account for 15%-18% of all percutaneous coronary intervention > (PCI). The main reasons for this are (1) the coronary arteries are like the branches of a tree with many ramifications and (2) because of axial plaque redistribution, especially after stent implantation, PCI of lesions located next to a coronary bifurcation almost inevitably cause plaque shifting in the side branches. PCI treatment of coronary bifurcation lesions remains challenging. Balloon dilatation treatment used to be associated with less than satisfactory immediate results, a high complication rate, and an unacceptable restenosis rate. The kissing balloon technique resulted in improved, though suboptimal, outcomes. Several approaches were then suggested, like rotative or directional atherectomy, but these techniques did not translate into significantly enhanced results. With the advent of second generation stents, in 1996, the authors decided to set up an observational study on coronary bifurcation stenting combined with a bench test of the various stents available. Over the last 5 years, techniques, strategies, and stent design have improved. As a result, the authors have been able to define a rational approach to coronary bifurcation stenting. This bench study analyzed the behavior of stents and allowed stents to be discarded that are not compatible with the treatment of coronary bifurcations. Most importantly, this study revealed that stent deformation due to the opening of a strut is a constant phenomenon that must be corrected by kissing balloon inflation. Moreover, it was observed that the opening of a stent strut into a side branch could permit the stenting, at least partly, of the side branch ostium. This resulted in the provocative concept of "stenting both branches with a single stent." Therefore, a simple approach is currently implemented in the majority of cases: stenting of the main branch with provisional stenting of the side branch. The technique consists of inserting a guidewire in each coronary branch. A stent is then positioned in the main branch with a wire being "jailed" in the side branch. The wires are then exchanged, starting with the main branch wire that is passed through the stent struts into the side branch. After opening the stent struts in the side branch, kissing balloon inflation is performed. A second stent is deployed in the side branch in the presence of suboptimal results only. Over the last 2 years, this technique has been associated with a 98% angiographic success rate in both branches. Two stents are used in 30%-35% of cases and final kissing balloon inflation is performed in > 95% of cases. The in-hospital major adverse cardiac events (MACE) rate is around 5% and 7-month target vessel revascularization (TVR) is 13%. Several stents specifically designed for coronary bifurcation lesions are currently being investigated. The objective is to simplify the approach for all users. In the near future, the use of drug-eluting stents should reduce the risk of restenosis.