This advertorial is sponsored by iVascular
Treatment of a chronic total occlusion (CTO)—a complete obstruction of the coronary artery that has persisted for more than three months—is one of the major challenges in the cath lab. A CTO consists of a proximal and distal cap, separated by an occluded segment, and due to the complexity involved in CTO percutaneous coronary intervention (PCI), the approach is seen as being so challenging that some have described it as the last frontier in interventional cardiology. In this advertorial, sponsored by iVascular, Cardiovascular News considers the challenges of treating CTOs, and details the features of the Navitian microcatheter, which has been designed specifically for the treatment of complex lesions and CTOs.
The literature has suggested a varying prevalence of CTOs in coronary artery disease patients, with data pointing towards an incidence rate of anywhere up to 30% of cases,1 with an even greater prevalence in diabetic or heart failure patients.2 Furthermore, 13% of cases exhibit more than one CTO. Historically, the vast majority of patients with a CTO are not treated using a percutaneous technique largely due to increased failure rates, technical complexity, cost and procedure length—with medical management or coronary artery bypass grafting (CABG) having been the favoured approaches in the bulk of cases.
However, this balance is gradually shifting, as percutaneous approaches continue to develop, and as new techniques, devices, and knowledge enter the field. Significant advances have been made in recent years that have led to increases in the success rate of PCI for CTO—advancing from close to 70% to more than 90%—which potentially open out the percutaneous option to a wider subset of patients.
This picture is summed up by EuroCTO board member Roberto Garbo (Maria Pia Hospital, Turin, Italy) who tells Cardiovascular News: “CTOs are the most complex coronary interventions, in which operator expertise and dedicated devices play a fundamental role in procedural success. In such complex scenarios, microcatheters are essential tools and high-quality performance is required.”
Deployment of a microcatheter is one of the essential techniques for successful CTO PCI, and the device can be used for a number of functions, including to increase the support of a guidewire, to advance through tortuous vessels, to gain access to side branches, facilitating parallel wiring, and plaque modificiation.3
In their 2018 paper in Vessel Plus,4 Lazzaro Paraggio and Francesco Burzotta (Institute of Cardiology, Università Cattolica del Sacro Cuore, Rome, Italy) document the important functions of microcatheters in the successful deployment of PCI for CTOs. They note that the key role of the microcatheter in CTO procedures can be summarised in three essential steps. Namely, these are: to safely place the CTO guidewire just in front of the lesion, to increase support and precision, and to allow guidewire exchange once the lesion has been crossed.
“All these steps could be used even in complex PCI procedures when a CTO-dedicated guidewire is used to cross a heavily calcified and/or narrowed lesion as explained before or when a workhorse guidewire should be manipulated more precisely which facilitates torque in the tip response,” Paraggio and Burzotta write. Finally, they add that microcatheters could be very useful in reducing guidewire kinking and prolapse while trying to cross a lesion immediately after a large
side branch.
Navitian: A new entrant in the microcatheter market
As approaches to CTO PCI have developed, so has microcatheter technology. The latest entrant to the evolving coronary microcatheter market is Navitian from iVascular. iVascular is a fast-growing company founded in 2010 in Barcelona, Spain with the aim of developing advanced medical devices and therapies for the treatment of cardiovascular system disorders. Thanks to know-how and investment in technology, iVascular has achieved the vertical integration of all the processes of their products.
Navitian has been designed specifically with complex lesions and CTOs in mind. The Navitian coronary microcatheter has a single lumen from the proximal end to the distal end, and it is used for support, passage of a guidewire and for the delivery of contrast media or saline solution. Features that have been targeted for CTOs in particular include a unique proprietary braiding technology, intended to optimise the pushability of the device and featuring a high penetration capacity, with low profiles and external conical transition to cross the most challenging lesions.
Furthermore, the tip of the Navitian device is completely adaptable thanks to its design, which features a c-cut radiopaque marker and radiopaque charged polymers, which are intended to aid the visibility of the device. The distal body of the catheter is coated with a proprietatry hydrophilic coating, Hydrax plus, which is durable and helps with catheter navigation through tortuous arteries and is designed to facilitate excellent trackability. The useful length of the catheter can be 135cm or 150cm, for antegrade and retrograde approach respectively. The product is compatible with 0.014” guidewires can support a maximum pressure of 2070kPa (300psi) with the distal end open.
Garbo describes the performance of the device as being at a “high-quality level”. “The performance of Navitian was really good both in antegrade and retrograde, the overall performance of the device in terms of profile, crossability and support was at high-quality level,” Garbo says. “In the retrograde approach, after balloon dilatation over stent struts, the Navitian 150 easily crossed the septal giving us good feedback for the rest of the procedure.”
References
- Lombardi W, Banerjee S. Chronic Total Occlusions [Internet]. The Cardiology Advisor. 2021 [cited 27 September 2021]. Available from: https://www.thecardiologyadvisor.com/home/decision-support-in-medicine/cardiology/chronic-total-occlusions/
- Konstantinidis N, Werner G, Deftereos S et al. Temporal Trends in Chronic Total Occlusion Interventions in Europe. Circulation: Cardiovascular Interventions. 2018;11(10).
- Vemmou E, Nikolakopoulos I, Xenogiannis I et al. Recent advances in microcatheter technology for the treatment of chronic total occlusions. Expert Review of Medical Devices. 2019;16(4):267-273.
- Paraggio L, Burzotta F, Aurigemma C et al. Usefulness of chronic total occlusion devices and techniques in other complex lesion subsets. Vessel Plus. 2019.
