chronic total occlusion
Complete coronary artery obstruction present for more than three months with TIMI 0 flow.
Full Definition
Chronic total occlusion (CTO) is defined as complete coronary artery obstruction with Thrombolysis in Myocardial Infarction (TIMI) 0 flow present for an estimated duration of at least three months. CTOs represent the most challenging lesion subset for percutaneous coronary intervention, requiring specialized techniques, equipment, and operator expertise. Common CTO intervention approaches include antegrade wire escalation, retrograde techniques via collateral circulation, and hybrid algorithms combining multiple strategies. Success rates have improved with dedicated CTO programs and refined techniques, though procedural complexity, radiation exposure, and contrast use remain elevated compared to conventional PCI. Successful CTO recanalization may improve angina symptoms, ventricular function, and potentially long-term survival.
Usage
Usage note: Must specify duration >3 months to distinguish from acute/subacute occlusions
In Context
- "Retrograde CTO intervention was performed via septal collaterals to recanalize the occluded LAD." — Complex intervention report
- "The chronic total occlusion was deemed unsuitable for percutaneous intervention due to anatomical complexity." — Heart team discussion