Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.
What Is a Chronic Total Occlusion (CTO)?
A chronic total occlusion is a peripheral arterial segment that has become completely blocked over an extended period, often developing a dense, fibrous, or calcified composition that can be more resistant to standard guidewire crossing techniques than a partial stenosis. CTOs are relatively common in advanced PAD, particularly in the femoropopliteal and infrapopliteal segments, and successfully crossing a CTO is often the most technically demanding step of a peripheral revascularization procedure.
How Are CTO Guidewires Designed?
CTO guidewires used in peripheral interventions are generally engineered with specific characteristics intended to support navigation through dense, occluded arterial segments:
- Core construction: Often built with nitinol or stainless-steel cores to balance flexibility with the pushability needed to advance through resistant tissue.
- Tip design: Specialized tip stiffness and shaping options allow physicians to select a wire suited to the specific occlusion characteristics.
- Coating: Hydrophilic coatings are commonly used to reduce friction and support smoother wire advancement through tortuous or occluded segments.
- Tip load range: Guidewires are typically available across a range of tip load (stiffness) options, allowing physicians to select a wire appropriate for the resistance expected in a given occlusion.
The specific guidewire selected depends on the occlusion's length, composition, and location, as determined by the treating physician based on preprocedural imaging and procedural findings.
What Role Do Introducer Sheaths Play?
An introducer sheath is placed at the vascular access site — commonly the femoral artery — to establish and maintain a stable, protected channel through which catheters, guidewires, balloons, and other devices can be introduced and exchanged during the procedure. Sheaths are sized in French (F) units corresponding to their outer diameter and are selected based on the profile of devices anticipated for use during the case, as well as the size and condition of the access vessel.
Why Do Access Tools Matter in PAD Procedures?
The choice of guidewire and sheath can meaningfully influence procedural efficiency and the physician's ability to successfully navigate complex anatomy, including tortuous vessels or chronic occlusions. A guidewire that lacks adequate support or pushability may make CTO crossing more difficult, while an appropriately sized, low-profile sheath is intended to help reduce access-site trauma and support smoother device exchanges throughout the case.
How Do These Tools Support the Overall PAD Workflow?
CTO guidewires and introducer sheaths are typically used at the start of a peripheral procedure to establish access and reach the target lesion, after which balloon catheters, atherectomy devices, or stents are introduced to treat the underlying arterial narrowing or occlusion. INVAMED's comprehensive catheter and guidewire portfolio is designed to support this full procedural workflow alongside its PAD-specific treatment devices.
Frequently Asked Questions
Why are specialized guidewires needed for chronic total occlusions?
CTOs often have a dense, fibrous, or calcified composition that can be more difficult to cross than a partial stenosis, requiring guidewires engineered with specific tip stiffness, coating, and support characteristics. The treating physician selects the appropriate wire based on the occlusion's imaging characteristics.
How is introducer sheath size determined?
Sheath size is generally selected based on the profile of the devices planned for use during the procedure and the size and condition of the vascular access site. This determination is made by the treating physician during procedural planning.
Are access tools used in every PAD procedure?
Vascular access using an introducer sheath is a standard step in virtually all percutaneous peripheral procedures, while specialized CTO guidewires are used specifically when a chronic total occlusion is identified. The specific tools selected depend on the individual case.
Related INVAMED Resources
- Comprehensive Catheter & Guidewire Systems
- Peripheral Arterial Disease (PAD) Products
- Contact INVAMED for More Information
Medical Disclaimer: This article is provided for general informational and educational purposes only and does not constitute medical advice, diagnosis, or treatment recommendation. It is not a substitute for consultation with a qualified healthcare professional. Product indications, availability, and regulatory status vary by country. Always refer to the official Instructions for Use (IFU) and consult a licensed physician for guidance specific to your situation. INVAMED devices are intended for use by trained healthcare professionals.