Magnetic Navigation System (magnetic + navigation_system)

Distribution by Scientific Domains


Selected Abstracts


Initial Clinical Experience with Cardiac Resynchronization Therapy Utilizing a Magnetic Navigation System

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2007
PETER GALLAGHER M.D.
Introduction: The placement of left ventricular (LV) leads during cardiac resynchronization therapy (CRT) involves many technical difficulties. These difficulties increase procedural times and decrease procedural success rates. Methods and Results: A total of 50 patients with severe cardiomyopathy (mean LV ejection fraction was 21 ± 6%) and a wide QRS underwent CRT implantation. Magnetic navigation (Stereotaxis, Inc.) was used to position a magnet-tipped 0.014, guidewire (CronusÔ guidewire) within the coronary sinus (CS) vasculature. LV leads were placed in a lateral CS branch, either using a standard CS delivery sheath or using a "bare-wire" approach without a CS delivery sheath. The mean total procedure time was 98.1 ± 29.1 minutes with a mean fluoroscopy time of 22.7 ± 15.1 minutes. The mean LV lead positioning time was 10.4 ± 7.6 minutes. The use of a delivery sheath was associated with longer procedure times 98 ± 32 minutes vs 80 ± 18 minutes (P = 0.029), fluoroscopy times 23 ± 15 minutes vs 13 ± 4 minutes (P = 0.0007) and LV lead positioning times 10 ± 6 minutes vs 4 ± 2 minutes (P = 0.015) when compared to a "bare-wire" approach. When compared with 52 nonmagnetic-assisted control CRT cases, magnetic navigation reduced total LV lead positioning times (10.4 ± 7.6 minutes vs 18.6 ± 18.9 minutes; P = 0.005). If more than one CS branch vessel was tested, magnetic navigation was associated with significantly shorter times for LV lead placement (16.2 ± 7.7 minutes vs 36.4 ± 23.4 minutes; P = 0.004). Conclusions: Magnetic navigation is a safe, feasible, and efficient tool for lateral LV lead placement during CRT. Magnetic navigation during CRT allows for control of the tip direction of the CronusÔ 0.014, guidewire using either a standard CS delivery sheath or "bare-wire" approach. Although there are some important limitations to the 0.014, CronusÔ magnetic navigation can decrease LV lead placement times compared with nonmagnetic-assisted control CRT cases, particularly if multiple CS branches are to be tested. [source]


A randomized comparison of the magnetic navigation system versus conventional percutaneous coronary intervention,

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 6 2008
DPHIL, Steve Ramcharitar BMBCH
Abstract Objective: A randomized comparison of the magnetic navigation system (MNS) to conventional guidewire techniques in percutaneous coronary interventions. Background: The MNS precisely directs a magnetized guidewire in vivo through two permanent external magnets. Methods: A total of 111 consecutive patients were enrolled. Crossing success, crossing-/fluoroscopy times, and contrast usage were directly compared. Lesions were classified according to the AHA/ACC criteria. Three tertiles of vessel/lesion complexity [low (<5), medium (6,10) and high (>10)] were defined using 3D reconstructions and angiographic information. Results: The crossing success for magnetic and the conventional wires were 93.3and 95.6%, respectively. Crossing and fluoroscopy times were longer with the magnetic wires (72.9 ± 50.3 sec vs. 58.1 ± 47.2 sec, P < 0.001 and 66.2 ± 44.1 sec vs. 55.2 ± 44.4 sec, P = 0.03, respectively). In vessels with low and medium complexity the magnetic wires had significantly longer times (P < 0.001) but for those with high scores (>10) a trend towards shorter times was observed. The MNS resulted in a small but significant reduction in contrast usage (2.3 ± 3.5 ml vs. 4.5 ± 4.4 ml, P < 0.001). Moreover by superimposing a virtual roadmap of the vessel on the live fluoroscopy image 48% of the lesions were crossed without requiring contrast agents with the MNS. Conclusion: The MNS has comparable crossing success to conventional PCI. It is relatively slower but there is a trend to support a potential advantage in more complex vessels. By simultaneously employing a virtual roadmap there is a small but significant reduction in contrast usage. © 2008 Wiley-Liss, Inc. [source]


A randomised controlled study comparing conventional and magnetic guidewires in a two-dimensional branching tortuous phantom simulating angulated coronary vessels

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 5 2007
DPHIL, Steve Ramcharitar MRCP
Objectives: To directly compare the magnetic navigation system (MNS) guidewires with conventional guidewires in branching tortuous phantoms with operators of varying MNS and percutaneous coronary intervention experience. Background: Vessel tortuosity, angulation, and side branches remain limiting factors in coronary interventions. The MNS addresses these limitations by precisely directing the tip of a magnetised guidewire in vivo aided by two permanent adjustable external magnets. Methods: Crossing and fluoroscopy times of six operators were evaluated in five tortuous Perspex® phantom vessels in three consecutive attempts. Standard guidewire (SG) usage was unrestricted. Two 2nd generation magnetic guidewires (MG) were used. Failure was noted if the cross was unsuccessful within 5 min. Results: The magnetic navigation was vastly superior to SG techniques with increasingly tortuous phantoms. It dramatically decreased both the crossing and fluoroscopy times with maximal reduction from 201.7 ± 111 to 36.4 ± 13 sec, P < 0.001 and 204.7 ± 24 to 47.2 ± 19 sec, P < 0.001, respectively. The MNS had a 98.8% procedural success rate compared to 68% with SG techniques. Moreover it considerably limited the amount of wire usage from 5.5 to 1.3. Operators with prior MG experience performed significantly better than those without, except in the simplest phantom where the difference was nonsignificant (33.8 ± 13 sec vs. 41.7 ± 17 sec, P = 0.2). Conclusion: MNS significantly reduces both the crossing and fluoroscopy times in tortuous coronary phantom models achieving excellent success rates with dramatic reductions in guidewire usage. Operators with prior MNS experience had an advantage over the inexperienced. © 2007 Wiley-Liss, Inc. [source]