Percutaneous Coronary Intervention for Intra-stent Chronic Total Occlusion Assisted by Stent Visualization Enhancement Technology

A 50-year-old female patient with a history of prior acute inferior myocardial infarction successfully treated 2 years earlier by primary percutaneous coronary intervention (PCI) with thrombus aspiration and implantation of a 3x30 mm bare-metal stent in the proximal right coronary artery (RCA) was submitted to coronary angiography after reappearance of effort angina. An initial coronary angiogram showed a chronic total occlusion (CTO) intra-stent with Rentrop III collateral filling of the RCA originating from distal left anterior descending (LAD). A mid LAD 60% stenosis and a 60% mid circumflex stenosis were considered non-significant since fractional flow reserve (FFR) was measured at 0.84 and 0.90 respectively. After demonstrating inferior wall viability by cardiac magnetic resonance imaging (MRI), a PCI was programmed two months after the initial coronary angiogram. The intra-stent CTO was ≥ 30 mm long, with no blunt stump and at least 2 small branches originating at its proximal cap level. Mid and distal RCA antegrade filling existed due to bridging collaterals. The crossing technique by guidewire exchange and use of a microcatheter is described. After balloon predilatation the RCA was recanalized. The use of a stent visualization enhancement technology (StentViz) helped understand the most probable procedure-related restenosis mechanisms (stent undersizing and underexpansion) and guided the subsequent successful implantation of two drug-eluting stents. The use of this technology is described step by step for this intervention.