Worldwide experience with the robotic navigation system in catheter ablation of atrial fibrillation: methodology, efficacy and safety.

INTRODUCTION: The Hansen Robotic system has been utilized in ablation procedures for atrial fibrillation (AF). However, because of the lack of tactile feedback and the rigidity of the robotic sheath, this approach could result in higher risk of complications. This worldwide survey reports a multicenter experience on the methodology, efficacy, and safety of the Hansen system in AF ablations. METHODS AND RESULTS: A questionnaire addressing questions on patient's demographics, procedural parameters, ablation success rate and safety information was sent to all centers where more than 50 robotic AF ablation cases have been performed. From June 2007 to December 2009, 1,728 procedures were performed at 12 centers utilizing the Hansen robotic navigation technology. The overall complication rate was 4.7% and the success rate was 67.1% after 18 ± 4 months of follow-up. In 5 low volume centers there appeared to be a learning curve of about 50 cases (complication rate 11.2% for the first 50 cases vs 3.7% for the 51-100 cases; P = 0.044) and a trend showing a decrease of complication rate with increasing case volume. However, in the remaining 7 centers no learning curve was present and the complication rate was stable over time (3.7% for the first 50 cases vs 3.6% for the 51st case thereafter; P = 0.942). CONCLUSION: The Hansen robotic system can be used for AF ablation safely. In low volume centers, there appeared to be a learning curve of the first 50 cases after which the complication rate decreased. With a higher case volume, the success rate increased.

Robotic navigation and ablation.

Robotic technologies have been developed to allow optimal catheter stability and reproducible catheter movements with the aim of achieving contiguous and transmural lesion delivery. Two systems for remote navigation of catheters within the heart have been developed; the first is based on a magnetic navigation system (MNS) Niobe, Stereotaxis, Saint-Louis, Missouri, USA, the second is based on a steerable sheath system (Sensei, Hansen Medical, Mountain View, CA, USA). Both robotic and magnetic navigation systems have proven to be feasible for performing ablation of both simple and complex arrhythmias, particularly atrial fibrillation. Studies to date have shown similar success rates for AF ablation compared to that of manual ablation, with many groups finding a reduction in fluoroscopy times. However, the early learning curve of cases demonstrated longer procedure times, mainly due to additional setup times. With centres performing increasing numbers of robotic ablations and the introduction of a pressure monitoring system, lower power settings and instinctive driving software, complication rates are reducing, and fluoroscopy times have been lower than manual ablation in many studies. As the demand for catheter ablation for arrhythmias such as atrial fibrillation increases and the number of centres performing these ablations increases, the demand for systems which reduce the hand skill requirement and improve the comfort of the operator will also increase.

Oesophageal temperature monitoring and incidence of oesophageal lesions after pulmonary vein isolation using a remote robotic navigation system.

AIMS: Oesophageal lesions (EL), a potential complication after pulmonary vein isolation (PVI), have been described recently. A new remote robotic navigation system (RNS; Hansen Medical) provides enhanced catheter stability along with more effective lesion placement. The aim of this prospective study was to evaluate temperature monitoring and incidence of EL when using RNS with an irrigated tip radiofrequency catheter for PVI. METHODS AND RESULTS: Circumferential PVI using RNS was performed in 73 patients (pts) with paroxysmal (n = 46, 63%) and persistent atrial fibrillation. An oesophageal temperature probe was placed in 58 (79.5%) pts and was integrated in the 3D-map (NavX). Power was limited to 25 W at the posterior wall, and in the case of an increase in temperature power was limited to 20 W. Endoscopy was performed in 42 pts within 24 h after PVI. In 44 of 58 (75.9%) pts, a significant rise in temperature (>39 degrees C) was observed. In 6 of 42 (14.3%) pts, an EL was found during endoscopy. In patients with EL, the body mass index (BMI) was significantly lower than in pts without EL (24.1 +/- 2.0 vs. 29.0 +/- 5.8, P = 0.047). The BMI of all patients with EL was <26, whereas all patients without EL had a BMI above 26. The EL showed brisk healing after re-endoscopy within 2 weeks in all pts. CONCLUSION: In patients undergoing PVI using the RNS, the incidence of EL is 14.3% when using power settings comparable to settings used in manual ablation. Patients with lower BMI (<26) are at higher risk for EL.

Experience with the hansen robotic system for atrial fibrillation ablation--lessons learned and techniques modified: Hansen in the real world.

INTRODUCTION: The Hansen robotic system has only recently been used in the United States for catheter ablation procedures in humans. Atrial fibrillation (AF) ablation may be performed utilizing this system. We report our management of complications with early experience of this system. METHODS AND RESULTS: All 71 patients in whom the system was utilized were included. In all patients, a 2-operator technique was to be employed; one operator manipulates the ablation catheter via the robot and the other manipulates the circular mapping and intracardiac echocardiogram catheters. There was no procedure-related mortality. All vascular complications occurred in the first 25 procedures performed. There were 6 intraoperative procedural-related complications. These included significant vascular complications (n = 4), one of whom required iliac vein stenting, and 2 cardiac tamponade (one related to a pop-phenomenon)-successfully treated by pericardiocentesis. Early complications (n = 3) were 1 tamponade several hours post-procedure, 1 vascular complication, and 1 pericarditis. Late complications included 5 patients with severe pulmonary vein stenosis (all in first 27 patients) and 1 patient with gastroparesis. All complications were successfully managed without persistent morbidity and occurred earlier in our experience. This led to specific alterations in our vascular access and ablation techniques. These include the use of a longer 14 Fr sheath, through which the robotic sheath is more safely advanced. The choice of ablation catheter and titration of power, particularly when the catheter has a perpendicular orientation to the atrial wall, is also important. CONCLUSIONS: The suggested modifications may make the system easier to use with the potential to reduce complications.

Atrial fibrillation ablation using a robotic catheter remote control system: initial human experience and long-term follow-up results.

OBJECTIVES: We present the initial clinical human experience with the use of a robotic remote navigation system (Hansen Medical, Mountain View, California), to perform left and right atrial mapping and radiofrequency ablation of atrial fibrillation (AF) and atrial flutter (AFL). BACKGROUND: Catheter ablation is an established curative modality for various arrhythmias. A robotic steerable sheath system (SSS) (Hansen Medical) allows better catheter stability and greater degrees of freedom of catheter movement. METHODS: A total of 40 patients (mean age 57 years) with antiarrhythmic drug (AAD)-refractory AF (23 had also concomitant documented typical AFL) were studied. Three-dimensional reconstruction of the corresponding atrial chamber anatomy was performed with the CARTO electroanatomic mapping system (Biosense Webster, Diamond Bar, California or the EnSite NavX system (St. Jude Medical, Minneapolis, Minnesota) in combination with the Artisan catheter (Hansen Medical). In patients undergoing AF ablation, 2 transseptal punctures were performed under intracardiac ultrasound (ICE) guidance, with one of the punctures being performed using SSS. Pulmonary vein antrum isolation was performed with a 3.5-mm thermocool catheter manipulated with the use of the SSS and was verified by circular mapping. Patients were followed clinically for recurrence of arrhythmia with an event transmitter and ambulatory holter monitoring. Clinical recurrence of AF/AFL was defined as AF/AFL episodes >1 min in duration. RESULTS: Pulmonary vein antrum isolation was performed in 40 patients, including 23 with concomitant typical AFL ablation. All pulmonary veins, including the superior vena cava, were successfully isolated. In 23 of 40 patients, cavotricuspid ablation was also performed with bidirectional block obtained. At 1-year follow-up, 34 patients (86%) and 5 patients were free from atrial arrhythmia off AADs and on AADs, respectively. CONCLUSIONS: This preliminary human experience suggests that mapping and ablation of AFL and AF using this novel robotic catheter with remote control system is feasible with similar results to conventional approach.