[Main stem intervention-Is one stent better than two after all?].

The current European Society of Cardiology (ESC) guideline recommendations give equal consideration to percutaneous coronary interventions (PCI) and bypass surgery for the treatment of main stem stenosis. Because of the anatomical setting, interventional treatment of main stem stenosis represents a complex PCI procedure. For this reason, extensive planning of the PCI with the use of intravascular imaging is necessary to assess the extent of calcification in the main stem itself and also in the proximal vascular segment of the anterior interventricular branch (left anterior descending, LAD) and the circumflex branch (RCX). Furthermore, an assessment of the vessel diameter is necessary for planning the PCI as well as for stent selection. Especially in the case of severely calcified lesions, careful and routine dissection of the lesion to be treated is essential. For this purpose, so-called cutting balloons, scoring balloons or debulking devices (rotational atherectomy, orbital atherectomy) can be used. In the case of a main stem stenosis involving the bifurcation, the choice of stent strategy depends on the extent of calcification of the daughter vessels (LAD and RCX), as well as the complexity of the bifurcation stenosis. The superiority of the so-called double kissing (DK) crush technique over a single stent strategy could be confirmed in a randomized trial and should be used in main stem bifurcation stenoses with pronounced calcification of the proximal segments of the LAD and RCX (stenosis length > 10 mm, and > 70% diameter stenosis). The already established 2‑stent strategies for the treatment of bifurcation stenosis could be modified or further developed. In preliminary studies the advantage of the so-called DK nano-crush technique and the DK culotte technique could be shown, whereby these initial results still have to be confirmed by larger randomized studies.