How to exchange a microcatheter (small catheter)

From the Guidelines

To exchange a microcatheter, a guidewire should be used as a rail system to maintain access to the target vessel, allowing for smooth transition between catheters. This technique is crucial in preserving vessel access throughout the procedure, reducing the risk of vessel trauma, spasm, or loss of access to difficult-to-navigate vessels 1.

Key Steps for Microcatheter Exchange

• Prepare the new microcatheter by flushing it with heparinized saline to remove air bubbles and prevent clot formation.
• Position a guidewire through the existing microcatheter, ensuring it extends beyond the catheter tip to maintain access to the target vessel.
• While firmly holding the guidewire in place, carefully withdraw the original microcatheter over the guidewire, making sure not to displace the wire from its position.
• Once the old catheter is completely removed, thread the new microcatheter over the same guidewire, advancing it to the desired location using fluoroscopic guidance.

Importance of Guidewire in Microcatheter Exchange

The use of a microcatheter for guidewire manipulation is a guiding principle in chronic total occlusion percutaneous coronary intervention, as it improves the precision of both rotational and longitudinal guidewire movements 1.

Benefits of Microcatheter Exchange Technique

The microcatheter exchange technique allows for rapid guidewire tip reshaping or exchange, while preserving previous guidewire crossing or advancement achieved, and inherently dilates retrograde collateral channels and protects them from wire-induced trauma 1.

From the Research

Exchanging Microcatheter: Techniques and Devices

• The process of exchanging a microcatheter is crucial in various medical procedures, including percutaneous coronary intervention (PCI) and chronic total occlusion (CTO) revascularization 2, 3, 4, 5.
• A novel technique, known as the "kissing microcatheter technique," has been described for exchanging a retrograde wire for an antegrade wire in the retrograde approach to CTO intervention 4.
• This technique involves placing a microcatheter inside the antegrade guiding catheter and manipulating the retrograde guidewire to pick up the tip of the antegrade microcatheter and enter it retrogradely.
• The use of a microcatheter can significantly improve guidewire steerability and penetration force, especially in tortuous, severely stenosed, and heavily calcified lesions 3.
• Various devices, including rapid exchange microcatheters (RXi) and guide catheter extensions, have been developed to facilitate microcatheter exchange and improve procedural outcomes in CTO revascularization 2, 3, 5.

Key Considerations

• The choice of microcatheter and guidewire depends on the specific procedure and lesion characteristics 2, 3, 5.
• The use of heparin-releasing or heparin-exposing surface coatings on guidewires can help reduce thrombus formation and improve safety 6.
• Procedural outcomes, including success rates and complications, can vary depending on the technique and devices used, as well as patient characteristics and lesion complexity 5.

Device-Specific Information

• The RXi microcatheter is a fibre-optic sensor technology-based device that allows for easier lesion negotiation and maintenance of guidewire position 2.
• The Micro Rx rapid exchange microcatheter is a novel device designed to provide additional guide wire support for crossing tortuous anatomy and tight lesions 3.
• Guide catheter extensions, such as those used in the Teleflex Chronic Total Occlusion Study, can help improve procedural outcomes in CTO revascularization 5.