Magnetic Navigation System Niobe Research Articles

Tele-robotics and artificial-intelligence in stroke care

In the last forty years, the field of medicine has experienced dramatic shifts in technology-enhanced surgical procedures – from its initial use in 1985 for neurosurgical biopsies to current implementation of systems such as magnetic-guided catheters for endovascular procedures. Systems such as the Niobe Magnetic Navigation system and CorPath GRX have allowed for utilization of a fully integrated surgical robotic systems for perioperative manipulation, as well as tele-controlled manipulation systems for telemedicine. These robotic systems hold tremendous potential for future implementation in cerebrovascular procedures, but lack of relevant clinical experience and uncharted ethical and legal territory for real-life tele-robotics have stalled their adoption for neurovascular surgery, and might present significant challenges for future development and widespread implementation. Yet, the promise that these technologies hold for dramatically improving the quality and accessibility of cerebrovascular procedures such as thrombectomy for acute stroke, drives the research and development of surgical robotics. These technologies, coupled with artificial intelligence (AI) capabilities such as machine learning, deep-learning, and outcome-based analyses and modifications, have the capability to uncover new dimensions within the realm of cerebrovascular surgery.

Evaluación del sistema de navegación magnética intracardiaca Niobe®, revisión sistemática de la literatura científica

Introducción y objetivos. Los métodos actuales de ablación conllevan sistemas de navegación manual y ablación cardiaca, y presentan ciertas limitaciones. El objetivo de este trabajo ha sido evaluar la eficacia y seguridad de los nuevos sistemas de navegación magnética intracardiaca.Métodos. Se hizo una revisión sistemática en las bases MedLine, Embase, Cochrane Library, CRD, ECRI, Hayes y bases de datos de HTA. Como términos Mesh se usaron: “electrophisiologic techniques”, “magnetics”, “stereotaxic techniques”, “heart catheterization” y “catheter ablation”. Los criterios de inclusión fueron estudios con adultos y lesiones cardíacas. La intervención fue el sistema de navegación magnética intracardiaca Niobe®. Los resultados medidos fueron: tiempos totales de procedimiento, tiempo de fluoroscopia, tiempo de colocación del catéter, tiempo de mapeo y tiempo de ablación. La calidad se evaluó con los cuestionarios CASPe y STROBE.Resultados. Se localizaron 467 referencias y se incluyeron 14. Hubo dos ensayos clínicos de calidad moderada y 10 estudios observacionales con calidad baja a moderada. Los ensayos presentaron un tiempo total de procedimiento mediante la intervención, igual o superior al comparador (151 y 113 vs. 151 y 77,2 minutos), mientras que los tiempos de fluoroscopia fueron inferiores (17,8 y 10,6 vs. 27,1 y 15,0 minutos). En los estudios observacionales, el tiempo total de intervención osciló entre 59 y 243 minutos para los sistemas magnéticos, frente a 57 a 332 minutos empleando técnicas convencionales. Los trabajos reflejaron la técnica magnética como segura, sin efectos secundarios graves.Conclusiones. No se ha logrado obtener información de calidad para afirmar que los sistemas de navegación magnética intracardiaca superen con claridad a los sistemas convencionales.

German stereotaxis-guided percutaneous coronary intervention study group: first multicenter real world experience

The Niobe Stereotaxis system consists of two 0.8 Tesla magnets and a navigation software allowing to move specially designed coronary wires. The aim of this observational multicenter study was to systematically evaluate the capability of the Stereotaxis Niobe Magnetic Navigation system to facilitate wire navigation during percutaneous coronary intervention (PCI), to determine the success rate of magnetically guided PCIs in a real-world setting, and to analyze procedure-related variables influencing the outcome data. One hundred and fifty seven patients underwent magnetically guided PCI in three German centers. Demographic variables of the patients, lesion quality determined by quantitative coronary angiography, success rate of the procedure as well as radiation time were analyzed. A subanalysis was performed for two periods (06/04-10/06 and 10/06-10/07) owing to a second generation of wires which was introduced at the beginning of the second period and procured-related learning curves of the operators. Mean age of the patients was 65 +/- 0.4 years (82% male, 18% female). 25% of the patients were diabetics. The lesions were characterized by high complexity (11% AHA type A, 25% type B1, 38% type B2, 25% type C). Mean percent lesion stenosis was 83.7 +/- 11.9%. The total fluoroscopy time was 13.2 +/- 0.3 min and the fluoroscopy time to cross lesion was 90.4 +/- 62.2 s. The overall success rate of the magnetically guided approach was 89%. All failures occurred within the first period were. In these cases, 80% of the failures could be successfully treated after switching to the conventional wires. On the other hand, between 10/06 and 10/07 three conventional PCI failures could be successfully treated using the Stereotaxis system. Magnetically guided PCI represents a promising tool for the treatment of dedicated lesions. There is a marked difference in the success rates of the method between the two different time periods which were analyzed, reflecting advances in the wire development and learning curves of the respective operators. Randomized controlled trials are required to determine the method's overall value and to identify subgroups that may particularly benefit.

Initial clinical experience of remote magnetic navigation system for catheter mapping and ablation of supraventricular tachycardias

A remote magnetic navigation system (MNS) has been developed for mapping and catheter ablation of cardiac arrhythmias. The present study evaluates the safety and feasibility of this system to perform radiofrequency (RF) ablation in patients with supraventricular tachycardias (SVT). A total of 32 patients (22 female; mean age 44 +/- 16 years) with documented SVT underwent mapping and ablation using Helios II (a 4-mm-tip magnetic catheter), under the guidance of the MNS (Niobe II, Stereotaxis, Inc.). Catheter ablation procedure with MNS was successful in 30/32 (94%) patients including all patients (27/27, 100%) with atrioventricular nodal reentrant tachycardia (AVNRT) and three of five patients (60%) with atrioventricular reentrant tachycardia (AVRT) without any complication. The procedural successful rate in patients with AVNRT was significantly higher than those in patients with AVRT (P < 0.001). Overall, the medium number of RF application using the MNS was 2 (mean 2.7 +/- 1.6, range 1 to 7), and the medium numbers of RF for AVNRT and AVRT were 2 and 3, respectively. There was no significant difference in the mean procedural time between patients with AVNRT and AVRT (126.3 +/- 38.6 vs. 138.0 +/- 40.3 min, P = 0.54). However, the mean fluoroscopy time was significantly shorter in patients with AVNRT than those with AVRT (5.7 +/- 3.0 vs. 16.5 +/- 2.5 min, P < 0.001). Among those patients with AVNRT, the mean procedural time (139.3 +/- 45.0 vs. 112.3 +/- 24.9 min, P = 0.07) and fluoroscopic time (3.2 +/- 1.0 vs. 8.0 +/- 2.2 min, P < 0.001) were shorter for the later 13 patients than the first 14 patients, suggesting a learning curve in using the MNS for RF ablation. The Niobe MNS is a new technique that can allow safe and effective remote-controlled navigation and minimize the need for fluoroscopic guidance for ablation catheter of AVNRT. However, further improvement is required to achieve a higher successful rate for treatment of AVRT.

Robotic approach to catheter ablation

The aim of this review is to introduce two novel techniques for catheter ablation of various arrhythmias in a remote-controlled fashion. The electromechanical system Sensei consists of two steerable sheaths that navigate conventional catheters via a 'master-slave' input device. The magnetic navigation system Niobe consists of two outer permanent magnets that cause a uniform magnetic field in which a specialized magnetically equipped catheter has to align in parallel. Both systems can interact with three-dimensional mapping systems and several reports on the clinical effectiveness of the systems have been published, which will be critically discussed in this review. These two novel technologies offer the fascinating option of performing catheter ablation in a remote-controlled fashion. Future studies and head-to-head comparisons with conventional ablation techniques will prove the impact of remote navigation, which hopefully will remove invasive electrophysiologists away from patients without the risks of reduced efficacy or increased procedural risks.

“Sequential” Mapping Mimicking “Simultaneous” Mapping Using Magnetic Navigation During Catheter Ablation of Supraventricular Tachycardia: Results of the Single DX Study

Introduction: The magnetic navigation system (MNS) allows remote‐controlled navigation of an ablation catheter from the control room. We tested the hypothesis, whether the MNS and a single additional diagnostic nonsteerable catheter would have the potential to identify the tachycardia substrate and allow subsequent ablation in patients with documented supraventricular tachycardia (SVT). Methods and Results: A total of 41 patients (24 females, age 45 ± 16 years) underwent an invasive electrophysiologic (EP) study using the MNS. Together with a conventional diagnostic catheter in the right ventricle, the magnetic catheter (MC) was used to investigate the underlying EP substrate in a sequential fashion and subsequently to perform radiofrequency (RF) ablation. A custom‐made device allowed the separate assessment of fluoroscopy deployed from the control and examination room. Using conventional EP criteria, identification of the underlying substrate was possible in all but 4 noninducible patients (no accessory pathway [AP], no dual atrioventricular [AV] node): APs were present in 10 patients, AV node re‐entrant tachycardia in 26 patients, and ectopic atrial tachycardia in 1 patient. Despite 3 patients, in which switching to conventional ablation was necessary (8%), all others were successfully treated using the MNS. Overall fluoroscopy amounted to a median of 3.4 minutes (interquartile range, 2.4–5.3) with only a median of 1.0 minute exposure for the investigator. Conclusions: Remote catheter ablation of SVT using the new MNS Niobe and a single conventional diagnostic catheter is feasible. Compared to conventional EP studies, a reduction of radiation exposure for both patients and investigators was demonstrated.

Remote-controlled magnetic ablation of a right anterolateral accessory pathway—The superior caval vein approach

An 18-year old male patient with recurrent supraventricular tachycardias was admitted for catheter ablation. Baseline ECG was consistent with right anterolateral accessory pathway (AP) conduction. The novel magnetic navigation system (MNS, Niobe Stereotaxis) in combination with a catheter advancer unit (Cardiodrive, Stereotaxis) allows a complete remote-controlled electrophysiologic study and ablation. Despite accurate identification of the AP insertion site using the MNS, a stable catheter position was not achieved from the inferior caval vein. Therefore, the venous access was switched to the superior caval vein approach using the left subclavian vein. The same magnetic field vector now resulted in a perfectly stable catheter position, and application of radiofrequency current immediately blocked AP conduction. This case demonstrates feasibility and safety of a complete remote-controlled ablation of a right-sided anterolateral accessory pathway using the superior approach in conjunction with the novel magnetic navigation system Niobe.

Erste In-vitro-Anwendung katheter- und magnetgesteuerter ferromagnetischer Polymerfilamente aus Nanopartikeln mit hitzeinduzierter Partikelabgabe unter Einsatz des Stereotaxis-Niobe®-Systems

To develop a new technique for intravascular guidance and the release of magnetized ferromagnetic nanoparticles using a polymerized filament by means of an external magnetic field. Ferromagnetic nanoscaled beads were embedded in temperature-sensitive gels to form filaments after polymerization. Deflection of the filaments was assessed in a Stereotaxis Niobe magnetic navigation system (MNS) in comparison with dedicated guide wires. The curvature was measured as a surrogate parameter for deflection. In combination with commercially available catheters, the filaments were navigated in a perfused aneurysmatic vessel model and a perfused branched vessel model under the influence of two permanent magnets of the Niobe MNS. The magnetic field vector was varied in all three dimensions. After positioning, the magnetic colloid-containing filaments were exposed to an electromagnetic field of 45 kA/m, 200 kHz for a period of 5 minutes for non-invasive heating. The filaments showed superior deflectability compared to the dedicated guide wires (p = 0.0091). The curvature was 0.54 +/- 0.12 mm(-1) for the filaments and 0.33 +/- 0.21 mm(-1) for the guide wires. In combination with angiography catheters, magnetic guidance and accumulation of specially designed filaments were possible in the perfused vessel model. Inductive heating allowed non-invasive disintegration and releasing of the nanoparticles in all filaments. This feasibility study shows that magnetic guidance and targeting of a specially designed magnetic colloid-containing filament and subsequent disintegration are feasible. This technique offers the potential for controlled local drug release.

Remote Catheter Ablation of Parahisian Accessory Pathways Using a Novel Magnetic Navigation System—A Report of Two Cases

Ablation of anteroseptal (parahisian) pathways may be difficult using conventional catheters. Two patients (51 and 20 years old) underwent ablation of a parahisian accessory pathway using the magnetic navigation system Niobe (Stereotaxis, Inc.), which consists of two external permanent magnets (0.08 Tesla) that steer a small magnet embedded in the tip of the ablation catheter. A motor drive allows the advancement or retraction of the catheter. From the control room, the ablation was performed using a single radiofrequency current application (fluoroscopy 3.2 and 6.0 minutes, respectively). The Niobe magnetic navigation system was successfully used to perform completely remote controlled mapping and ablation of parahisian accessory pathways.