From the Guidelines
Crossing a chronic total occlusion (CTO) requires a specialized approach using dedicated wires, and I recommend starting with a tapered, polymer-jacketed wire like the Fielder XT or Pilot 200 for initial attempts through microchannels, as supported by the guiding principles for CTO-PCI 1. When selecting a wire, consider the CTO angiographic characteristics, local availability, and expertise. The antegrade approach should be attempted first, using techniques like wire escalation or parallel wiring. For complex lesions, consider retrograde approaches using collateral channels. During the procedure, use microcatheters like the Corsair or Finecross to provide wire support and facilitate exchanges, as they have a marker at the distal tip, providing adequate fluoroscopic feedback of its actual position and also providing greater freedom of advancement with a lower profile and better wire-to-lumen internal diameter ratio 1. Dual injection angiography helps visualize the distal vessel and guide wire manipulation. CTO crossing requires patience and meticulous technique, as these lesions contain organized thrombus, fibrous tissue, and calcification that create mechanical barriers. Success rates improve with operator experience and proper case selection, with contemporary techniques achieving 85-90% success rates in experienced centers, highlighting the importance of following the 7 key principles for CTO-PCI, including symptom improvement as the primary indication, dual coronary angiography, and use of a microcatheter 1.
Some key points to consider when crossing a CTO include:
- Using a microcatheter to facilitate guidewire manipulation and exchanges
- Selecting the appropriate wire based on the CTO angiographic characteristics and local availability
- Attempting the antegrade approach first, with techniques like wire escalation or parallel wiring
- Considering retrograde approaches for complex lesions
- Using dual injection angiography to visualize the distal vessel and guide wire manipulation
- Following the 7 key principles for CTO-PCI to optimize success and minimize complications, as outlined in the guiding principles for CTO-PCI 1.
By following these principles and using the appropriate techniques and equipment, operators can improve their success rates and provide better outcomes for patients with CTOs. The primary indication for CTO-PCI is to improve symptoms, and the procedure should be performed in centers with the necessary equipment, expertise, and experience to optimize success and minimize complications 1. Overall, CTO crossing requires a specialized approach and careful consideration of the patient's symptoms, angiographic characteristics, and local availability of equipment and expertise.
From the Research
CTO Crossing Wire Techniques
- The success of percutaneous intervention for chronic total occlusion (CTO) depends mainly on crossing the lesion with a wire 2.
- Intravascular ultrasound (IVUS) guidance can be useful in identifying the site of entry and returning to the true lumen after entering a false lumen 2, 3.
- IVUS-guided wiring re-entry technique has been shown to be feasible and safe for the recanalization of complex CTO lesions 3.
IVUS-Guided Wiring Techniques
- IVUS imaging provides the opportunity to visualize the occluded vessel and aid guidewire advancement 4.
- A bi-radial, IVUS-guided CTO wiring technique using 6 Fr catheters via bilateral transradial approach has been described as a successful approach for blunt stump CTO 5.
- IVUS-guided wiring technique can be used to identify the entry point into the subintimal space and guide another stiff wire to re-enter the true lumen 3.
Success Rates and Outcomes
- The success rate of IVUS-guided stumpless wiring of CTOs has been reported to be around 77% 4.
- The use of IVUS guidance has been shown to have a good success rate in CTO-PCI, with no significant impact of the learning curve on success rates 4.
- The IVUS-guided wiring re-entry technique has been shown to have a high success rate of 85% in complex CTO lesions 3.