ABSTRACT
Introduction Percutaneous transluminal coronary angioplasty (PTCA) has established itself as an important alternative to coronary artery bypass surgery in the treatment of coronary artery disease. A continuing development of tools and techniques has led to an increase in the number and complexity of cases performed annually.1 In the 1977-81 angioplasty registry compiled by the National Heart Lung and Blood Institute (NHLBI), total occlusions represented 2% of all lesions attempted; in the 1985-86 registry, this had increased to 10%. Following landmark studies, proving the benefit of intracoronary stents over plain balloon angioplasty, the routine use of intracoronary stents has widely increased the indications for PTCA.2-4 However, recanalization and maintenance of bloodflow through a previously chronically occluded coronary artery is still a major challenge. The relatively low procedural success rates5-8 and high recurrence rates9-11 made percutaneous attempts at recanalization of chronic occlusions a less popular indication for percutaneous coronary intervention. It was only after the introduction of improved guidewire technology12-14 and the demonstration of a positive influence of intracoronary stent implantation on long-term vessel patency15-17
that percutaneous treatment of chronic occlusions became an acceptable alternative for surgical treatment. Three randomized trials of primary stent placement versus balloon angioplasty alone, enrolling at least 100 patients, have
been reported (SICCO, GISSOC, and TOSCA-1). Though the trials varied in inclusion criteria, design, anti-thrombotic regimen, and endpoints, their results were substantially concordant in demonstrating reduced restenosis and reduced re-occlusion when a strategy of routine stenting of recanalized non-acute occlusions was followed. The key design features of these protocols and quantitative angiographic results are provided in Tables 8.1 and 8.2.
