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Cook Evolution lead extraction sheath uses rotation for cardiac lead removal
The mechanical dilator sheath set brings an ergonomic design to a complex and delicate procedure.
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A new revolving mechanical sheath system could provide another tool in the armamentarium for cardiac lead extraction.
The Cook Medical Evolution mechanical dilator sheath set, designed for the removal of fibrous tissue-laden cardiac leads as well as in-dwelling catheters and other foreign objects, possesses some attributes distinguishing it from laser lead removal systems.
Ergonomic design
The Evolution system, which uses no electricity and is hand-powered, consists of an outer and inner sheath. The revolving polypropylene inner dilator sheath, fitted with a stainless steel tip at its distal end, is connected to an ergonomically designed handle and trigger that rotates it. The inner sheath is contained within an outer telescoping polymer sheath. The semi-threaded steel tip, which can be used to provide counter-traction, is designed to dilate tissue surrounding the lead or catheter. The inner sheath diameter is available in several sizes, from 7.0 Fr to 13.0 Fr.
The device is hand-operated by the interventionalist using a trigger mechanism that rotates the threaded tip of the inner sheath that then pulls itself slowly down the lead. The handle and trigger are designed in such a way that the interventionalist performing the procedure can actually ‘feel’ the ease or difficulty of movement of the sheath through the trigger, providing the operator with a tactile indication of the device’s progress down the lead or through lesions. The sheaths are single-use and disposable, according to the manufacturer.
The challenge of lead removal
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Source: Cook Medical |
According to a Cook press release, about 750,000 leads were implanted in 2007 in patients with implantable cardiac defibrillators or pacemakers across Europe. As many as 52,000 of these leads required extraction due to infection, malfunction or the need for new leads. “Removing leads is a complex endeavor. There are many variables to consider including the number of leads, their construction and geometry and duration of implantation,” Loren D. Berenbom, MD, clinical assistant professor and director of electrophysiology at the University of Kansas Hospital in Kansas City, Mo., told Cardiology Today. “There are a variety of tools for lead extraction, each of which has its place, and this is one more tool in the toolbox. It is important to understand that there is not any one tool you can always use to remove every lead successfully, safely and efficiently.”
According to Berenbom, cardiac leads that have been in place for a long time can be particularly difficult to remove. The buildup of fibrous tissue, which can grow around the lead and can get into the coils characteristic of ICD leads, can present complications for the interventionalist.
“The ideal case for this device is somebody with a single lead, and it is especially helpful for a larger caliber lead, particularly an ICD lead that is nonisodiametric and where tissues can grow into the coils along the shaft,” Berenbom explained. “With this device, you can work your way down that lead pretty expeditiously and relatively safely remove it.”
Advantages, disadvantages
Traditional lead removal devices, and in particular laser-based and other electrosurgical systems, are still the standard of care for lead extraction. Results from the Pacing Lead Extraction With The Excimer Sheath (PLEXES) trial, published in the Journal of the American College of Cardiology in 1999, suggested that laser-assisted pacemaker lead extraction had significant clinical advantages over non-laser extraction. Such systems, although effective, can be expensive and are only available for use in facilities equipped to handle them. As a result, interventionalists using the Evolution sheaths have more flexibility in terms of the location of the procedure.
“In many practices, these procedures are done in an operating room because of the concern that some major vascular catastrophe could ensue from even a very carefully done procedure,” John M. Miller, MD, professor of medicine at the Indiana University School of Medicine in Indianapolis, told Cardiology Today. “When we do these procedures in cath labs, something like only one or two out of every eight labs has the power capability for laser. With this device, it can be done anywhere, so that may be a mild advantage.”
Another potential advantage of the Evolution sheath is its ability to navigate torturous vessels. Since the rotating inner sheath adheres closely to the surface and shape of the lead, the sheath remains fastened securely in place.
“One of the problems that laser or any other extraction method has is when you are going from the vein and shoulder underneath the collar bone from the main vein to the superior vena cava. Although that is a relatively curved area, it can make a bit of an obtuse angle,” Miller said. “The laser shoots straight ahead and runs the risk for tearing the vessel or of cauterizing or ablating right through the vessel wall into the right chest cavity. Whether it is flexible enough to follow the curve of the catheter and to hug it enough so that it will not run astray like that, it is not going to do additional tissue damage.”
One potential complication that can arise from use of the device is the danger of wrapping multiple leads around one another.
“Since this device revolves, it does have the potential to wrap a smaller caliber lead around it, and that is certainly something you want to avoid,” Berenbom cautioned. “You have to watch yourself more carefully if you have multiple leads in, especially when you have a lead you want to remain in place and would prefer not to remove.” - by Eric Raible
For more information:
- To learn more about the Cook Evolution mechanical dilator sheath set, visit cookmedical.com.
- Wilkoff B, Byrd C, Love C, et al. Pacemaker lead extraction with the laser sheath: Results from the Pacing Lead Extraction With The Excimer Sheath (PLEXES) trial. J Am Coll Cardiol. 1999;33: 1671-1676.