Percutaneous Coronary Intervention of Chronic Total Occlusion (CTO)

For patients with limiting angina in spite of medical therapy coronary revascularisation either by coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) is extremely efficacious for symptom relief. Whether to treat using the surgical option or by PCI is decided by several factors which impact on the relative efficacy of each technique. These include a patient’s presenting coronary syndrome, their co-morbidities and their coronary anatomy. Coronary artery stenoses usually pose little challenge to current percutaneous techniques. During PCI, the aim is to cross the diseased segment of vessel with a fine guidewire (0.014″ in diameter), dilate the narrowed lumen and implant a stent to scaffold the vessel walls open. The wire is steered by rotating and advancing its curved tip through the vessel lumen until it sits in a distal position and can provide a rail to introduce subsequent equipment such as angioplasty balloons and stents. Difficulties are encountered when treating heavily calcified vessels and where atheroma sits at bifurcations or trifurcations, but arguably the most challenging subset of lesion to treat by PCI are those which are chronically occluded.