Sponsored by ReFlow Medical Corporation
Forging a Path
An elegant new catheter provides a winning CTO solution.
Over the past 2 decades, endovascular techniques have become the preferred approach in the treatment of peripheral artery disease (PAD). In most cases, delivery of endovascular devices requires passage of a guidewire across or through the lesion. Once the guidewire is in position, various technologies can be used to administer therapy in an effort to restore blood flow to the affected vascular bed. When the vessel lumen is still patent, passage of the guidewire can be achieved in most cases. The more challenging situations are in the case of arterial chronic total occlusions (CTOs), which are frequently encountered during endovascular interventions and reported in up to 40% of patients with symptomatic PAD.1
As a CTO ages, a hard, fibrous cap can form, making penetration of the occlusion more difficult or, in some cases, impossible. Attempts to cross these lesions with a wire can result in the inability to penetrate the proximal or distal caps. Intraluminal crossing is preferred, but in some cases, the wire will deflect off the cap and enter the subintimal channel.
The traditional approach for treating CTOs has been a support catheter paired with a physician’s preferred guidewire. Support catheters work in tandem with the guidewire, providing additional column strength, increasing the “pushability” of the chosen device, and enabling the guidewire/catheter assembly to move through the occlusion.
In approximately 20% of cases, the standard catheter/wire combination is not enough to safely and reliably span the lesion.2,3 Several new technologies aim to circumvent this clinical conundrum by focusing on reentry from the subintimal space, engaging or avoiding the CTO, or ablating the tissue occluding the vessel lumen.
Specialized CTO crossing devices, such as ultrasound-guided vibration angioplasty, blunt microdissection catheters, and reentry catheters have been developed to facilitate the introduction and placement of the guidewire into distal arteries. However, despite the excellent evidence, these devices are not used in routine clinical practice. Devices such as Crosser (Bard Peripheral Vascular, Inc.), TruePath (Boston Scientific Corporation), and Wildcat and Kittycat (Avinger, Inc.) can be very cost prohibitive, making doctors reluctant to pull them off the shelf early in a procedure. In addition, these devices may employ complicated actions that require a learning curve in a situation in which user experience is critical.
THE WINGMAN CATHETER
The Wingman Crossing Catheter (ReFlow Medical, Inc.) offers a simple but effective approach to crossing CTOs. The device has a unique, extendable radiopaque tip that is manually controlled to engage with a calcified cap, creating a channel for the wire to follow. “The beveled edge is needle-like,” said John Laird, MD, Medical Director of UC Davis Vascular Center, “offering a lot of help to get through a dense proximal cap.”
A basic push-and-twist motion anchors the tip into the cap and allows for penetration of the CTO (Figure 1). The tip can be retracted and then redeployed when the operator encounters stenoses or other areas of calcification. When the tip is retracted, the catheter is tracked and follows the wire as a support catheter. “This is a very useful device for breaking through caps; the extendable tip makes all the difference,” said Mahmood Razavi, MD, Research Director at St. Joseph Vascular Institute in Orange, California. “The extendable tip is one of the unique features of this device.”
The Wingman is compatible with the physician-preferred guidewire and currently comes in 0.035-inch and 0.014-inch options. The through-lumen of the device also provides a conduit for the delivery of saline solutions or diagnostic and therapeutic agents. More than 200 cases by over 40 physicians in nine countries have been performed utilizing the Wingman catheter; the following is a brief overview of some of the clinical experiences to date.
EXPERIENCE WITH WINGMAN CATHETER
Calcifications are problematic; wires that cannot readily penetrate these blockages will be deflected or redirected. “The ability to get through calcified lesions is better than I ever expected,” said Gary Ansel, MD, System Medical Chief of Vascular Services at OhioHealth/Riverside Methodist Hospital in Columbus, Ohio. “[With] this device, you can basically burr your way through the calcifications.”
CTOs can occur in a variety of arteries, making it difficult to adopt a universal approach. “The Wingman provides options for addressing the multiple and variable CTOs that can span from the SFA to the popliteal and tibial arteries,” said J.A. Mustapha, MD, FACC, FSCAI, Director of Cardiovascular Catheterization Laboratories at MetroHealth Hospital in Wyoming, Michigan. “This device has a significant advantage with its 0.014-inch and 0.035-inch systems, giving it a range of therapy from the groin to the feet.”
When a traditional guidewire and catheter fail to cross a CTO, routine procedures must often be abandoned, and the clock starts ticking. “We have been able to observe the Wingman under both fluoroscopy and ultrasound, providing us with direct visualization and confirmation of the device’s position,” said Dr. Mustapha. “This direct visualization gives us full confidence to cross the most complex lesions in a very short period of time.” Dr. Ansel agrees that rapidity is a key advantage. “For something to be economically and procedurally viable, it cannot add much more time to a case. Procedure time is always related to complications.”
CTOs continue to provide clinical challenges. Many CTO devices, while specialized, can interrupt the flow of a procedure and introduce the potential for complications. During an interventional treatment, the ability to maintain routine as much as possible saves time and money, while increasing patient safety and improving outcomes. The Wingman’s rapid and routine approach to lesion crossing largely sidesteps concerns about cost or complicated techniques by providing the best of both worlds: the function and simplicity of a support catheter combined with the benefits of a specialized CTO device. Look for Wingman Crossing Catheter options in the coronary arena soon.
Mahmood K. Razavi, MD, is Research Director at St. Joseph Vascular Institute in Orange, California. He has disclosed that he serves on the scientific advisory board of ReFlow Medical. Dr. Razavi may be reached at email@example.com.
John R. Laird, MD, is Medical Director of UC Davis Vascular Center in Sacramento, California. He has disclosed that he serves on the scientific advisory board of ReFlow Medical. Dr. Laird may be reached at firstname.lastname@example.org.
Gary M. Ansel, MD, is System Medical Chief of Vascular Services at OhioHealth/Riverside Methodist Hospital in Columbus, Ohio. He has disclosed that he serves on the scientific advisory board of ReFlow Medical. Dr. Ansel may be reached at email@example.com.
J. A. Mustapha, MD, FACC, FSCAI, is with Metro Health Hospital in Wyoming, Michigan. He has disclosed consulting agreements with Bard Peripheral Vascular, Boston Scientific, Cardiovascular Systems, Inc., Cordis Corporation, and Terumo Medical. Dr. Mustapha may be reached at firstname.lastname@example.org.
Naoto Inoue, MD, is with the Division of Cardiovascular Medicine, Sendai Kousei Hospital in Sendai, Miyagi, Japan. He has disclosed that he received no compensation related to this article and is not a consultant to ReFlow Medical. Dr. Inoue may be reached at email@example.com.
This article was written by Joely Johnson Mork, MS, with the assistance of ReFlow Medical, Inc.
Results from case studies are not necessarily predictive of results in other cases. Results in other cases may vary.
1. Boguszewski A, Torey J, Pai R, et al. Intraluminal recanalization of SFA CTOs. Endovascular Today. 2010;9:33-38.
2. Rogers J, Laird J. Overview of new technologies for lower extremity revascularization. Circulation. 2007;116:2072-2085.
3. Bolia A, Miles KA, Brennan J, Bell PR. Percutaneous transluminal angioplasty of occlusions of the femoral and popliteal arteries by subintimal dissection. Cardiovasc Interv Radiol. 1990;13:357-363.