chronic total occlusion
Also written as: CTO — Chronic Total Occlusion
A completely blocked coronary artery with TIMI 0 flow present for more than three months.
Full Definition
Chronic total occlusion (CTO) represents a complete blockage of a coronary artery with TIMI 0 flow that has been present for at least three months, confirmed by clinical history or previous angiography. CTO lesions are among the most challenging targets for percutaneous coronary intervention, requiring specialized techniques, equipment, and expertise. These procedures often involve complex strategies including antegrade wire escalation, retrograde approaches through collateral vessels, and hybrid algorithms. Successful CTO revascularization can provide significant symptomatic relief and may improve left ventricular function in selected patients, though the procedures carry higher complication rates and longer procedural times than conventional PCI.
Usage
Usage note: CTO abbreviation widely used. Spell out on first use in patient education materials. Hyphenate when used as compound modifier.
In Context
- "Chronic total occlusion of the right coronary artery was successfully recanalized using a retrograde approach." — Complex PCI procedural report
- "The hybrid algorithm was employed for this challenging chronic total occlusion with extensive calcification." — Interventional cardiology case discussion