Why Treat Chronic Total Occlusion without Stents? - A Short Comment

Abstract

The treatment of chronic total occlusions is complex and associated with several risks and problems. Among therapeutic options including bypass surgery and medical therapy PCI represents an important strategy. PCI with stents, however, has limitations in such lesions due to characteristics like lesion length, unknown reference diameter and delayed stent coverage. Drug coated balloons have shown promising properties to overcome some of those limitations: They promote positive vessel remodeling and have a minimal thrombosis rate. In a first multicenter study it has been shown that drug coated balloons in proper indications and applied with appropriate technique might become a new treatment option for patients with chronic total occlusions. CommentaryChronic total occlusions (CTO) of coronary arteries have been a focus point of research in interventional cardiology for several years. Recanalization, balloon dilatation and implantation of drug eluting stents (DES) are recognized treatment options for patients with symptomatic CTO. Recanalization of CTO ranks among the most complicated percutaneous coronary interventions (PCI) and the procedures are to be performed by well-equipped and experienced centers. During the last decades the procedural success rates increased due to improved technical equipment and increasing operator experience [1,2].It is still uncertain whether PCI is the optimal treatment method for CTO and it competes with coronary artery bypass grafts (CABG) and medical treatment. Large retrospective registries have shown a reduction of adverse events and a clinical improvement after successful CTO PCI [3,4]. The only recently conducted DECISION-CTO trial [5] was the first large randomized controlled trial (RCT) to compare different treatment modalities for CTO. It failed to show a significant difference between PCI and optimal medical therapy. In general CTO PCI should only be considered for symptomatic patients with viable myocardium and no contraindications for PCI.Further research and new strategies might improve CTO PCI in the future, amongst them bioresorbable vascular scaffolds and drug coated balloons (DCB). CTO vessels usually have long lesions to be treated [6], have often an unknown vascular diameter and might have a number of side branches, often not readily recognizable beforehand.Thus, there are several characteristics of CTO that call for a stent free PCI approach. In the attempt of covering the lesion completely frequently more than 5 cm of the affected vessel have to be stented during CTO PCI. DES of such lengths has shown an increased risk of diffuse restenosis and other stent-linked complications [7]. The selection of a proper stent size can be difficult due to the lack of a reference diameter. An inappropriate stent size however can lead to either extensive vessel damage or to secondary malapposition. Also side branches might be occluded.In addition, even in comparison with similar long non-CTO lesions a delayed coverage of stent struts has been observed in CTO after DES imp...