Remote Magnetic Navigation: Human Experience in Pulmonary Vein Ablation

Remote Magnetic Navigation: Human Experience in Pulmonary Vein Ablation

Luigi Di Biase, Tamer S. Fahmy, Dimpi Patel, Rong Bai, Kenneth Civello, Oussama M. Wazni, Mohamed Kanj, Claude S. Elayi, Chi Keong Ching, Mohamed Khan, Lucie Popova, Robert A. Schweikert, Jennifer E. Cummings, J. David Burkhardt, David O. Martin, Mandeep Bhargava, Thomas Dresing, Walid Saliba, Mauricio Arruda, Andrea Natale

We assessed the feasibility and efficacy of remote magnetic navigation (MN) and ablation in patients with atrial fibrillation (AF). Forty-five consecutive patients with AF underwent ablation using the MN system in a stepwise approach: circumferential pulmonary vein (PV) ablation, pulmonary vein antrum isolation (PVAI), and conventional PVAI. After step 2 ablation only 1 (PV) in 4 patients was electrically isolated. Charring on the ablation catheter tip was seen in 15 patients. The remote MN system is a feasible technique. Inability to isolate the PVs was associated with a significant rate. With the present catheter technology, effective lesions cannot be achieved in most cases. This appears to impact cure rate of AF patients.

Objectives

We aimed at assessing the feasibility and efficacy of remote magnetic navigation (MN) and ablation in patients with atrial fibrillation (AF).

Background

This novel MN system could facilitate standardization of the procedures, reducing the importance of the operator skill.

Methods

After becoming familiar with the system in 48 previous patients, 45 consecutive patients with AF were considered for ablation using the Niobe II remote magnetic system (Stereotaxis, St. Louis, Missouri) in a stepwise approach: circumferential pulmonary vein ablation (CPVA), pulmonary vein antrum isolation (PVAI), and, if failed, PVAI using the conventional approach. Remote navigation was done using the coordinate or the wand approach. Ablation end point was electrical disconnection of the pulmonary veins (PVs).

Results

Using the coordinate approach, the target location was reached in only 60% of the sites, whereas by using the wand approach 100% of the sites could be reached. After step 2 ablation, only 1 PV in 4 patients (8%) could be electrically isolated. Charring on the ablation catheter tip was seen in 15 (33%) of the cases. In 23 patients, all PVs were isolated with the conventional thermocool catheter, and in 22 patients only the right PVs were isolated with the conventional catheter. After a mean follow-up period of 11 ± 2 months, recurrence was seen in 5 patients (22%) with complete PVAI and in 20 patients (90%) with incomplete PVAI.

Conclusions

Remote navigation using a magnetic system is a feasible technique. With the present catheter technology, effective lesions cannot be achieved in most cases. This appears to impact the cure rate of AF patients.