Cath Lab Digest - April 2008 - (Page 8)

8 NEW TECHNOLOGY APRIL 2008 continued from page 1 Orbital Atherectomy: A new treatment for complex peripheral arterial disease Orbital atherectomy is performed over a 0.014” guidewire, in contrast to a 0.009” wire with rotational atherectomy. The larger diameter guidewire makes it easier to advance across a tight stenosis. More support is given, especially when a contralateral approach is utilized or when a supportive guidewire is essential for tracking of an adjunctive device, such as a self-expanding stent delivery catheter. I have not had angiographic evidence of particulate embolization (no reflow or distal cutoffs). The orbiting action and ability to increase the orbit circumference by increasing the orbiting speed result in a substantial time saving during the atherectomy procedure. There are other differences in performance specific to lesion characteristics between the two types of atherectomy. The Figure 1a. The Diamondback 360° (Cardiovascular Systems, Inc., St. Paul, MN). to use lower atmospheres and thus reduce the potential for barotraumas. The Diamondback works for fibrous tissue as well, but luminal gain is not as dramatic in soft plaque. For total occlusions, what is your technique for gaining access to the distal lumen? Do you use a support catheter or combination support catheter, and specialty crossing guidewires before placing the ViperWire guidewire? After performing several hundred cases with total occlusions, I have become fairly consistent with the use of a support catheter such as Spectranetics QuickCross (Colorado Springs, CO) and a Terumo Glidewire (Ann Arbor, MI). These two devices have provided me great success in gaining access in more than 90% of cases in which I needed to access the distal true lumen. In rare instances, I use a reentry catheter such as Outback (Cordis Endovascular, Miami, FL) or Pioneer. For below-theknee lesions, I consistently rely on the Asahi family of guidewires (Miracle Bros, Confienza and Pilot, distributed by Abbott Vascular, Redwood City, CA), with close to 95% success. Recently, I have been very impressed by the ability of the Safe Cross reentry system to cross total occlusions in peripheral vascular cases. This device is extremely useful in complex plaque due to its ability to deliver radiofrequency energy while the wire is being advanced. After gaining access to true lumen, I utilize either a 0.035” QuickCross support catheter or 0.020” catheter to exchange for a ViperWire guidewire, and then perform orbital atherectomy. The Diamondback has a range of crown sizes and operates at three preset rotational speeds. How do you determine the appropriate size crown and what is your current technique in terms of initial versus final rotational speed? It is very important for the operator to be familiar with the two types of crowns available with this system — classic and solid — as well as the controller touch screen interface and Orbital atherectomy requires a single insertion, with plaque debulking occurring as the crown is advanced back and forth through the lesion. The particles “sanded” from the vessel wall are very small and are less apt to cause significant distal embolization. Also, orbital atherectomy allows continuous blood flow through stenosed (but not totally occluded) vessels, which not only continuously flushes particulate downstream but may reduce device-generated heat. How is orbital atherectomy different from directional atherectomy? Directional atherectomy is performed using multiple passes with slight rotations of the device to remove plaque in a single plane with each pass. As the atherectomy catheter is advanced, the plaque removed is packed into the nose cone and after several passes, the catheter is removed to empty the nose cone. Orbital atherectomy requires a single insertion, with plaque debulking occurring as the crown is advanced back and forth through the lesion. The diamond coating on the orbital crown is of a fine granular texture and the particles “sanded” from the vessel wall are very small and are less apt to cause significant distal embolization, which can be a problem with directional atherectomy. In my experience with the Diamondback, Diamondback, in my practice experience, performs appreciably better in calcified lesions than directional atherectomy. In what type of lesions does orbital atherectomy perform well? I have used it with great success in calcified or fibrotic smaller arteries below the knee as well as femoropopliteal vessels. Before the Diamondback was commercially available, there were many lesions that I would not have attempted to cross with atherectomy or other debulking devices that were available. The ViperWire has good pushability and torque response. The Diamondback does require the use of this proprietary guidewire, which has a 0.023” spring coil tip. After treating a calcified lesion, I find that the angiographic result is frequently excellent and almost stent-like in appearance. I do use less adjunctive therapy following orbital atherectomy, other than perhaps a simple balloon inflation to finalize a smooth lumen. When using a balloon after debulking with the Diamondback, it is possible Figure 1b. The Diamondback 360° controller. Figure 2. The orbital motion of the crown removes plaque from within a diseased arterial segment; as the crown orbits, the debulking area increases, and with increments in speed, the area increases further. the displayed information. The controller has preset speeds (low, medium and high). I start at low speed, followed by medium and then high, if needed, and advance the crown slowly (1 cm per second). Figures 3a and 3b demonstrate the speed and expected lumen diameter for each device size and type. It is critical to realize that lack of resistance in a vessel during an orbital atherectomy procedure does not mean device Disclosure: Dr. Dave discloses that he receives grant and research support from Cardiovascular Systems Inc.

Table of Contents Feed for the Digital Edition of Cath Lab Digest - April 2008

Cath Lab Digest - April 2008 Kaiser San Rafael Medical Center Orbital Atherectomy: A New Treatment for Complex Peripheral Arterial Disease Ask the Clinical Instructor: A Q&A Column for Those New to the Cath Lab Contents Clinical Editor’s Corner CEU Education Center The Missing Link in STEMI Interventions — Thrombus Aspiration during Primary Percutaneous Coronary Intervention Predicting Stent Thrombosis Using A Clinical Risk Score Use of a New Guidewire: The Tigerwire Should I Stay or Should I Go? Weighing Options for New Opportunities Navigating Tortuous Coronary Sinus Anatomy Using a Bipolar Lead The National Society of Radiology Practitioner Assistants (NSRPA) Holds 9th Annual Educational Conference For Medical Imaging Physician Extenders and Mid-Level Healthcare Providers Cath Lab & Beyond: A Meeting Update The Ten-Minute Interview with… Dale Hansen RT, CVT Sometimes, You Just Know Twin Circumflex Arteries: A Rare Coronary Artery Anomaly What Do You Think? Meetings Calendar News from the American College of Cardiology (ACC) Scientific Session and the Society of Cardiovascular Angiography & Interventions (SCAI) Annual Scientific Sessions in Partnership with the ACC i2 Summit Clinical & Industry News Cath Laughs Classifieds Advertisers Index

Cath Lab Digest - April 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.