Do We Know How to Treat Bifurcation Coronary Lesions

Lesions located in an arterial bifurcation have traditionally been a challenge for percutaneous coronary intervention. At the time when balloon angioplasty was being used, these interventions were associated with increased risk of vascular occlusion, especially in the lateral branch, and also with a higher rate of restenosis. Suboptimal results in the main vessel, which sometimes had to be accepted for fear of losing the lateral branch, and the higher content of elastic fibers in these coronary segments seemed to explain these problems, at least partially. With the arrival of stents, treatment of bifurcations changed radically. After implanting a stent, we can ‘‘ensure’’ excellent immediate results in the main vessel and avoid problems arising from the delayed elastic recoil inherent to these lesions. However, the stent in the main vessel ‘‘cages’’ the lateral branch and may jeopardize the ostium due to displacement of the plaque or the carina itself. In turn, implanting a stent in the lateral branch is even more challenging. As can be seen in the Figure, implanting a stent in the lateral branch often entails significant technical problems that are compounded by the need to implant a stent in the main vessel. The fundamental problem arises in patients with major lateral branches, whose clinical outcome will depend on the results of the intervention. Bifurcation treatment outcome depends on many factors, among which we highlight the size of the vessels involved, the angle they form, whether the lateral branch ostium is affected, carina morphology and volume, and the distribution and characteristics of the atheromatous plaque determining luminal stenosis. Although many angiographic classifications have been proposed to categorize bifurcation lesions, until recently none had achieved universal acceptance because of their complexity and uncertain value in guiding the intervention. We must remember that the bifurcation itself complicates angiographic assessment of stenosis severity in the various arterial segments involved. Thus, despite using multiple projections, branch shortening and overlapping phenomena are common. In fact, bifurcations are a major source of variability in the SYNTAX (SYNergy between percutaneous coronary