MIAMI BEACH – When the "wire and catheter" approach fails, crossing devices come into play for recanalizing vessels during endovascular interventions, according to Dr. John Rundback.
Specialized crossing devices may improve the ability to treat chronic total occlusions (CTOs), including calcified and long, complex lesions that can be very difficult to cross, particularly in the infrapopliteal region, said Dr. Rundback, medical director of the Interventional Institute at Holy Name Medical Center, Briarcliff Manor, N.Y.
Courtesy Holy Name Medical Center
Dr. John Rundback
When it comes to specialized crossing devices, there is a whole spectrum available, and many are relatively new on the market, so experience with them is limited, Dr. Rundback said at the International Symposium on Endovascular Therapy 2013.
The goal with each, however, is to remain intraluminal and to maximize the interventional options, he said, noting that goal is particularly relevant with the advent of drug-eluting balloons.
Although the data are sparse, and these devices – which are generally used in patients who have failed traditional wire and catheter crossing – have not been compared to wire and catheter techniques in a rigorous fashion, it is nonetheless clear that there are cases in which these devices will be needed.
"You have to sort of pick one or two and keep them in your lab, and gain familiarity," he said.
The approved and emerging devices he discussed include the Viance and Enteer peripheral CTO crossing devices (Covidien), the Crosser CTO device (Bard Peripheral Vascular), the Wildcat and Kittycat CTO devices (Avinger), and the TruePath crossing device (Boston Scientific).
Viance and Enteer
The Viance crossing catheter is a high-speed rotating recanalization device, and the Enteer reentry system is a unique reentry catheter. The two were studied together as a novel overall strategy, Dr. Rundback explained.
In a study involving 66 patients, which led to the recent approval of the device, CTO lesion lengths were reasonably long, much like those Dr. Runback said he sees in his practice. However, moderate to severe calcification was present in only 42% of patients, which is less than he generally sees, and a fair amount of tortuosity was present in 50%-60% of patients.
About two-thirds of the cases involved the superficial femoral artery (SFA), and the remaining cases were in the tibial circulation. Overall, the approach was safe, and the success rate was 85%, Dr. Rundback said.
The Crosser
The latest version of this device, approved in the United States for both coronary and peripheral indications, involves a dedicated hydraulic vibrational system that provides translational force through the lumen.
"It’s the one we tend to use the most in our practice, and our junior associates have had great success with this device," Dr. Rundback noted.
The Crosser device is unique in that it establishes a luminal plane where you often don’t see anything, and moves quite smoothly and easily through the lumen, he said.
In the PATRIOT (Peripheral Approach to Recanalization in Occluded Totals) study of this device, 85 guide wire–refractory peripheral CTO patients were treated with a high technical success rate of 84% and no perforations.
Most cases involved the SFA, but about a third were popliteal or below. Lesion length was reasonable (average, 117.5 mm), and about 75% of patients had old, calcified lesions.
Treatment was quick, taking only about 2 minutes on average.
"That has been our experience as well. These actually work very quickly to reestablish straight-line flow," he said, noting that it is important to be cautious, nonetheless.
"You can get extraluminal without knowing it. [The technique] requires a certain amount of practice and tactile feedback to become familiar with the utility of these devices," he said.
Wildcat and Kittycat
These devices are rotating crossing devices (Kittycat is a small-vessel device) that have shown promise in trials.
In the CONNECT (Chronic Total Occlusion Crossing with the Wildcat Catheter) trial, the technical success rate was 89%, and safety was greater than 95% in patients with an average lesion length of 174 mm, about half of whom had moderately calcified lesions.
The newest incarnations of these rotating crossing devices use optical coherence technology that allows visualization of the lumen as the occlusion is traversed.
Dr. Rundback said he has no personal experience with these devices, but said that the prospect of visualizing the position within the lumen "does have some sort of empirical appeal and may provide real, true benefit in terms of staying in the lumen."
TruePath
This FDA-approved crossing device uses a high-speed, rotating diamond-studded burr to advance through lesions.