Artikel
Computer-controlled magnetic navigation in neurovascular procedures: In vitro results
Computergestützte magnetische Navigation bei neurovaskulären Eingriffen: In-vitro-Ergebnisse
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Veröffentlicht: | 11. April 2007 |
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Gliederung
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Objective: Standard microguidewires used in present interventional neuroradiology have a predefined shape of the tip that can not be changed while the guidewire is in the vessel. Although the idea of using magnetism to direct intravascular catheters is not new, its feasibility has only recently been described for cardiovascular applications. The aim of this study was to evaluate, in vitro, a novel magnetic navigation system (MNS) that generates a magnetic field to control the movement and deflection of a microguidewire. This system can be used to reshape the guidewire-tip in vivo without removing the wire from the body, thereby potentially facilitating navigation along tortuous paths or multiple acute curves.
Methods: The MNS consists of two permanent magnets positioned on either side of the fluoroscopy table. The magnet positions relative to each other, are computer-controlled to create a constant precisely–controlled magnetic field in the defined region of interest. This field enables omni-directional rotation of a 0.014 inch magnetic microguidewire (MG) equipped with a 2-3mm long permanent magnet positioned at the tip. The speed of navigation, the accuracy in a tortuous vessel anatomy and the potentials for navigating into in vitro aneurysms were tested by four investigators with differing experience in neurointervention and compared to navigation with a standard, manually-controlled microguidewire (SG).
Results: Navigation using the MG was faster (p=0.0056) and more accurate (0.2mistakes/trial vs. 2.6 mistakes/trial)when used by the less experienced investigators. There were no statistical differences between the MG and the SG for the experienced investigator. One aneurysm with an acute angulation from the carrier vessel could be navigated only with the MG. In this instance, the SG failed, even after multiple re-shaping manoeuvres.
Conclusions: Our data suggest that magnetic navigation seems to be easier, more accurate and faster when employed by less experienced investigators in interventional Neuroradiology using magnetic navigation. We presume that the features of this magnetic system may improve the efficacy and safety of challenging neuointerventional procedures.