chronic total occlusion
Also written as: CTO — chronic total occlusion
Complete arterial blockage present for more than three months, representing the most challenging lesions for endovascular intervention.
Full Definition
Chronic total occlusion (CTO) is defined as complete arterial obstruction with no antegrade flow (TIMI 0 flow) that has been present for at least three months. These lesions represent the most technically challenging cases in interventional angiology due to their length, calcification, tortuosity, and the presence of organized thrombus and fibrous tissue. CTO revascularization requires specialized techniques, equipment, and expertise, with success rates lower than conventional stenoses but potentially significant clinical benefits when achieved. The chronicity distinguishes these lesions from acute occlusions and influences treatment approaches and success rates.
Usage
Usage note: Three-month timeframe distinguishes chronic from subacute occlusions.
In Context
- "The chronic total occlusion of the superficial femoral artery was successfully recanalized using specialized guidewires." — Interventional radiology procedure report
- "Given the complexity of the chronic total occlusion, a staged approach was planned." — Multidisciplinary team discussion