Remote magnetic navigation for ventricular ablation: did the machine win this round?

Abstract

Remote magnetic navigation has been available as a tool for mapping and ablation for well over a decade. In that period of time, it has shown to be useful in nearly every type of ablation procedure from the most simple to the most complex [1][2][3]. Some operators prefer the system for atrial fibrillation ablation, others for ventricular tachycardia ablation, and some use it for any ablation. Despite numerous publications showing reductions in fluoroscopic exposure and the obvious benefits of not wearing lead and standing tableside for hours, remote magnetic navigation has not become the standard of care in the world [4]. Most publications appear to show similar success rates, and many show favorable complication rates [5][6][7]. So what is the limitation to universal acceptance? In addition, many centers have purchased the system, yet it sits unused. Why would a physician give up a more comfortable procedure to perform an ablation wearing lead and being exposed to more radiation?One of the major factors preventing adoption is cost. Not only is the system itself expensive but it also requires shielding, specific X-ray systems, support specifications, a significant space requirement, and cannot be close to an MRI system. Outfitting an existing EP laboratory with a system would likely require significant construction costs. In general, it is much easier to plan for a system in new construction.Once the system is installed, the operator must commit to overcoming the learning curve. Navigation with the system is quite different than manual navigation. Looping the catheter allows access to areas that cannot be reached directly. There is no fixed curve, which allows great versatility but is not always intuitive. Procedures will take longer in the beginning, and learning the advanced techniques takes significant time and patience. In the current world, where we are pushed toward efficiency and increasing volume and throughput, this time is certainly a sacrifice. It is understandable why some would choose not to continue using a system that slows them down under such pressure.Perhaps the most challenging limitation is technological lag. Magnetic navigation systems require partnerships with catheter manufacturing companies and mapping companies to fully enjoy use of the system. These companies have their own financial goals, and since magnetic navigation is only a small portion of catheter sales, the incentive to advance the technology is not present. Since the release of the open-irrigated magnetic ablation catheter almost 10 years ago, catheter technology has significantly changed. New irrigation platforms, contact force sensing, and balloon-based technologies have entered the field, yet the magnetic catheter has remained unchanged in that time. There is ample opportunity to improve the magnetic catheter itself with increased magnetic force, improved handling, and irrigation, but this cannot occur without significant capital or a willing partner.Despite these limitations, magnetic navigation seems to have found a niche...

Design and Evaluation of a Steerable Magnetic Sheath for Cardiac Ablations

“…2B), and each has limited independence in position and orientation control. In a recent editorial, J. Burkhart pointed out that one of the main limitations of remote magnetic navigation is the limited variety of magnetic catheters [15].…”

Remote magnetic navigation versus contact force technology: The two faces of the ablation lesion

“…RMN was associated with higher signal shrinkage with a mean positive figure in comparison to CF‐guided ablation. Catheter stability is higher in RMN for both acquisition and ablation . The trade‐off is a decrease in maximal force applied, which although creates a smaller more homogenous lesion, may lead to only partial isolation, especially when more anatomically complex lesions are involved .…”

“…Furthermore, when undergoing catheter ablation for ventricular arrhythmias, mapping via RMN tends to demonstrate less distortion and produce a more accurate representation of the targeted chamber . A more uniform and constant contact likely leads to more homogenous lesions . In a meta‐analysis of studies of ventricular tachycardia ablation, RMN was associated with significantly lower ventricular tachycardia recurrence as well as procedural adverse events compared to manually guided ablation …”