Editorial Comment

A Better Way to Get There?

David R. Holmes, Jr.,* MD

Mayo Clinic,Rochester, MN

The technical demands placed on the interventional-ist involved in the treatment of cardiovascular diseasecontinue to grow. There are several drivers for thisgrowth; these include the treatment of more difficultand complex lesions such as diffuse disease, bifurca-tions, chronic total occlusion, as well as the treatmentof different vascular beds such as the intracerebral ves-sels. Obviously, an essential component of the laterincludes the requisite-specific knowledge of the anat-omy. From a technical standpoint, access to the lesion/lesions to be treated is fundamental. Such access is of-ten complicated by details of the specific anatomy aswell as equipment available and operator experience.

The use of magnetic guidance has some very attractivefeatures that could help to alleviate or minimize some ofthe technical demands. Obvious advantages mightinclude quicker access and shorter crossing time in com-plex lesions, less radiation exposure, and perhaps lessvessel trauma. These advantages could serve as some ofthe metrics by which to evaluate this technology.

The paper by Ramcharitar et al. assesses some ofthese advantages in the randomized-controlled studywhich compares conventional and magnetic guidewiresin a two-dimensional branching tortuous phantom. Dif-ferent groups of operators characterized by their famil-iarity with the magnetic guidance system (Stereotaxis)were studied. The most experienced magnetic-guidedsystem operators were also the most experienced inter-ventionalists.

Not surprisingly, as a whole, operators with priormagnetic guidance exposure performed significantlybetter than those without. The exception to this wasthe simplest and most straightforward lesions. Otherimportant findings were also obtained. Magnetic guid-ance was associated with marked reduction in bothcrossing and fluoroscopy time and perhaps most impor-tantly a marked increase in successful crossing of thelesion using the magnetic guidance approach. Theauthors conclude appropriately ‘‘magnetic navigationsystem significantly reduces both the crossing and fluo-roscopy times in tortuous coronary phantom modelsachieving excellent success rates with dramatic reduc-tions in guidewire usage.’’There are of course limitations—some of these are

technical and some of them include the process ofcare. The phantom used in this study was only two-dimensional and employed static road mapping ratherthan the dynamic road mapping during live interven-tions. Vessel trauma may still occur, for example, ifimmediately after crossing the tortuous vessel, forwardpressure of a wire might still result in damage to thevessel wall. It will remain difficult to document the ef-ficacy in randomized patient trials because of designissues as it will be impossible to ‘‘blind’’ the opera-tors. Yet another important issue relates to patientflow—with very straightforward lesions, magnetic con-trol will not be needed. And yet in some patients/lesions which look straightforward, access may beinexplicably difficult. While it might be wonderful tohave a magnetic guidance system for access in everycatheterization laboratory room, that is impractical andvery costly. Despite these limitations, magnetic guid-ance for very difficult anatomy is an importantadvance in the field and will be useful in optimizingoutcome.

*Correspondence to: David R. Holmes, Jr., MD, 200 First Street

SW, Rochester, MN. E-mail: holmes.david@mayo.edu

Received 5 September 2007; Revision accepted 5 September 2007

DOI 10.1002/ccd.21384

Published online 24 October 2007 in Wiley InterScience (www.

interscience.wiley.com).

' 2007 Wiley-Liss, Inc.

Catheterization and Cardiovascular Interventions 70:669 (2007)