Robotic Ablation of Atrial Fibrillation Saves Time and Irradiation Dose

Annals of Clinical Research and Trials

Citation: Samir Rafla, Mostafa Nawar, Amr Kamal, Josef Kautzner (2017). Robotic Ablation of Atrial Fibrillation Saves Time and Irradiation Dose

Open Access Full Text Article

Annals of Clinical Research and

Trials

Volume 1 • Issue 2 • 008 www.scientonline.org Ann clin Res Trials

Research Article

Robotic Ablation of Atrial Fibrillation Saves Time and Irradiation

Dose

Samir Rafla*, Mostafa Nawar, Amr Kamal

and Josef Kautzner

Department of Cardiology and Angiology, Alexandria

University, IKEM institute, Prague, Czech Republic,

Egypt

Introduction

The goals of AF ablation procedures are to prevent AF by either eliminating the

trigger that initiates AF or by altering the arrhythmogenic substrate [1-4]. The most

commonly employed ablation strategy today, which involves the electrical isolation of

the pulmonary veins by creation of circumferential lesions around the right and the

left PV ostia, probably impacts both the trigger and substrate of AF [5-7]. Catheter

based ablation of AF places significant demands on the skill and experience of the

electrophysiologist. The objectives of developing new technologies to facilitate these

procedures include precise and stable catheter navigation, reduced radiation exposure,

shorter procedures, and cost effectiveness. While new technologies generally increase

the cost of a procedure when they are introduced, the costs may be justified if they

improve outcomes.

The Hansen Sensei robotic system (Hansen Medical Inc., Mountain View, California

®) integrates robotic technology with computed movement. The key aspect is an

electromechanical manipulator that is designed to provide physicians with precise

catheter control and 3-D navigation within the heart from the workstation, while the

operator is away from the operating table [8]. The aim of this work was to evaluate

the feasibility of catheter ablation in patients with paroxysmal atrial fibrillation using

different technologies and its effect on terms of procedural efficacy and success rate

Patients and Methods

We studied 150 patients (pts) (86 males and 64 females) having a mean age of 51.3 yrs

(54 > 50, 96 below 50 yrs), who suffered from symptomatic drug refractory paroxysmal

*Corresponding author: Samir Rafla, Department

of Cardiology and Angiology, Alexandria University,

IKEM institute, Prague, Czech Republic, Egypt, E-mail:

smrafla@yahoo.com

Abstract

This analysis assesses the effect of Robotic technique on the results of ablation of

paroxysmal AF.

Methods: We studied 150 patients (pts) (86 males and 64 females) having a mean

age of 51.3 yrs (54 > 50, 96 below 50 yrs), who suffered from symptomatic drug refractory

paroxysmal AF. Work was done in IKEM hospital in Prague. Cardiac MSCT image

integration to the 3D electroanatomic LA map was used in 106 pts (70.6%, however all

of them underwent intracardiac echo guided imaging during the ablation procedure. 40

pts underwent manual RF ablation using CARTO, 40 pts underwent ablation using NavX

system, 70 pts underwent robotic ablation using Sensui system. Pulmonary vein isolation

was done to all pts using either pulmonary vein (PV) antral isolation in 116 (77.3%) or

circumferential pulmonary vein ablation in 34 pts (22.7%). All pts were followed at 3, 6, 9,

and 12 months.

Results: Procedural time was significantly longer in manual (202.0 ± 19.4 minutes)

compared to Robot group (146.4 ± 10.8 minutes). Total fluoroscopy time was significantly

shorter in Robot group (6.9 ± 1.9 minutes) compared to non-robotic group (19.9 ± 3.1

minutes). The mean fluoroscopy dose area-product was significantly lower in Robot group

(552.7 ± 194.1 μ Gy.cm2) compared to manual group (2257.2± 568.1 μGy.cm2).

Conclusions: The robotic group showed evident and clear benefit of the use of robotic

navigation system in the form of much shorter total procedure time, shorter total fluoroscopy

time and fluoroscopy exposure dose with less number of ablation points.

Keywords: Atrial fibrillation, Ablation techniques, Pulmonary vein isolation, Robotic

ablation procedures, Radiation, Administration and dosage

This article was published in the following Scient Open Access Journal:

Annals of Clinical Research and Trials

Received November 28, 2017; Accepted December 06, 2017; Published December 13, 2017

Citation: Samir Rafla, Mostafa Nawar, Amr Kamal, Josef Kautzner (2017). Robotic Ablation of Atrial Fibrillation Saves Time and Irradiation Dose

Page 2 of 5

Volume 1 • Issue 2 • 008 www.scientonline.org Ann clin Res Trials

AF. Work was done IKEM institute, Prague, Czech Republic from

2008 to 2010 as part of the doctoral degree of Dr. Amr Kamal.

Patients were subjected to the following

I- Full History Taking & Clinical Examination

II- Baseline 12- Lead Electrocardiogram (ECG)

III- Routine Laboratory Investigations

VI- Cardiac Imaging Modalities

• Chest X ray Examination

• Transthoracic Echocardiography (TTE)

• Transesophageal Echocardiography(TEE)

• Cardiac Multislice Computed Tomography (MSCT)

• Intracardiac Echocardiography(ICE)

V- Preprocedural Management

• Informed consent

• Preprocedural anticoagulation

• Preprocedural antiarrhythmic drugs

VI- Procedural management

• Vascular access

• Procedural sedation

• Procedural anticoagulation

• Double transseptal puncture

• Catheters positioning

VII- Three dimensional electroanatomic mapping

• The EnSite NavX® system (Endocardial Solutions, St. Jude

Medical, Inc.)

• The CARTO mapping system (Biosense, Diamond Bar, CA,

USA®)

VIII- Radiofrequency Catheter Ablation

• Robotic Catheter Navigation System (Sensei System,

Hansen Medical, Inc. ®)

• Manual Catheter Ablation

XI- Post procedural management & follow up patients were

followed up regularly at the outpatient arrhythmia Clinic at 3, 6, 9

and 12 months, as well as at any time for any possible attacks of

arrhythmic recurrences.

Patients were followed up as regards

• Clinical symptoms

• Standard 12- lead Electrocardiogram (ECG)

• In hospital Telemetry

• 7- Day Holter Monitoring

• Outpatient Mobile Telemetry with Loop Recording

The patients were divided into three groups

• Group C (Carto): Forty patients with paroxysmal atrial

fibrillation who underwent ablation using CARTO

technology and manual ablation.

• Group N (NavX): Forty patients with paroxysmal

atrial fibrillation who underwent ablation using NavX

technology and manual ablation.

Group R (Robotic): Seventy patients with paroxysmal atrial

fibrillation who underwent ablation using NavX technology with

use of robotic catheter navigation system (Sensei System).

Integration of CT Image into CARTO Mapping System: CT

image fusion with 3D Carto map was done to most of the patients;

the CT image was imported into the EAM system using special

software (CartomergeTM, Biosense Webster, Inc., Diamond Bar, CA,

USA) (Figure 1).

Integration of CT Image into EnSite NavX Mapping System

The contrast enhanced CT image in standard DICOM format

Figure 1: Segmentation process of 3D-CT image using Carto Merge Software.

Citation: Samir Rafla, Mostafa Nawar, Amr Kamal, Josef Kautzner (2017). Robotic Ablation of Atrial Fibrillation Saves Time and Irradiation Dose

Page 3 of 5

Volume 1 • Issue 2 • 008 www.scientonline.org Ann clin Res Trials

was imported into the mapping system using the EnSite System

software tools for digital image fusion in the same way.

Ablation Procedure: Ablation was done in all patients using

the open irrigation ablation catheter in the power controlled

mode either manually or after mounting on Artisan catheter for

remote robotic catheter navigation system.

The end point of the ablation was the disconnection between

the PV and LA, and noninducibility of AF/AFL.

Periprocedural Anticoagulation during AF Catheter Ablation:

After the procedure, heparin infusion is discontinued. Warfarin

therapy is restarted in all patients either the same evening of the

ablation procedure or next morning. In the initial period, LMWH

(e.g., Enoxaparin at a dosage of 0.5-1.0 mg/kg twice a day) is

often given as bridging therapy by starting 3-4 hours after the

ablation or alternatively heparin is administered intravenously

until the day after the procedure, starting about 3 hours after

sheath removal at a rate of 1000 IU/h. Thereafter, LMWH is

administrated until the INR is ≥2. Once the therapeutic INR is

achieved, LMWH is stopped, whereas warfarin is continued for

at least 3 months. The anticoagulation strategy after the initial 3

months varies according to patient and procedure related factors

and for most patients with a CHADS2 score of ≥2 to continue longterm

warfarin treatment with a targeted INR of 2-3 is usually

needed.

Cardiac MSCT image integration to the 3D electroanatomic LA

map was used in 106 pts (70.6%, however all of them underwent

intracardiac echo guided imaging during the ablation procedure. 40

pts underwent manual RF ablation using CARTO, 40 pts underwent

ablation using NavX system, 70 pts underwent robotic ablation

using Sensui system. Pulmonary vein isolation was done to all pts

using either pulmonary vein (PV) antral isolation in 116 (77.3%)

or circumferential pulmonary vein ablation in 34 pts (22.7%).

Circumferential PV ablation was usually associated with posterior

wall ablation. All pts were followed at 3, 6, 9, and 12 months.

Statistical analysis of the data

Data were fed to the computer and analyzed using IBM SPSS

software package version 20.0. Qualitative data were described

using number and percentage. Quantitative data were described

using mean and standard deviation. Comparison between

different groups regarding categorical variables was tested using

Chi-square test. When more than 20% of the cells have expected

count less than 5, correction for chi-square was conducted

using Fisher’s exact test. Correlations between two quantitative

variables were assessed using Pearson coefficient. Significance

of the obtained results was judged at the 5% level. Data was

presented as Median (Min. -Max.) for abnormally distributed data

or Mean ± SD. for normally distributed data.

Results

Total fluoroscopy time: Manual group vs. Robotic group 19.9

minutes vs. 6.9 minutes, P <0.000 (Table 1). 34 patients (22.6%)

developed early recurrence of AF after an initial blanking period

of 3 months. We had 16 patients (10.6%) with treatment failure at

short term follow up, this number increased to 18 patients (12%)

at midterm follow up and further small increase to 20 patients

(13.3%) at long term follow up, recurrences were any episode of

AF and /or AFL/AT > 30 seconds after the blanking period. The

incidence of recurrence of AF in males was 13% (11/86), 14% in

females (9/64), P NS.

Complications rate (Table 2): None in 92,5%, air embolism

zero, cardiac tamponade zero, trivial pericardial effusion 1,

groin hematoma 5%, pulmonary vein stenosis > 50% zero. No

difference in complications between robotic and manual groups.

Long term success rate

The primary efficacy endpoint was complete success with no

recurrences from 9 months and up to 12 months after ablation

procedure without use of AAD in 77.5% of manual group and

85.7% in Robot group. Long term comprehensive success

was also calculated from 9 months and up to 12 months after

ablation procedure as the sum of primary and secondary efficacy

endpoints, reflecting the reduction of AF burden, it was 82.5 %

for manual group and 91.4 % for Robot group (Table 3).

Groups No of Patients Mean P

Total no. of ablation points

Manual Gr 80 72 0.000

Robotic Gr 70 49.9

Total ablation time

Manual Gr 80 2094 0.000

Robotic Gr 70 1323

Total fluoroscopy time

Manual Gr 80 19.9 0.000

Robotic Gr 70 6.9

Total fluoroscopy dose

Manual Gr 80 2257 0.000

Robotic Gr 70 552

Table 1: Comparison between manual and robotic groups as regards ablation

points.

Complications

Manual group

(n = 80)

Robotic group

(n = 70) X2 P

No % No %

No complications 74 92.5 66 94.4 0.432 0.692

Trivial pericardial effusion 2 2.5 0 0 1.332 0.235

Cardiac tamponade 0 0 0 0 0.000 1.000

Air embolism 0 0 1 1.4 0.647 0.622

Small groin hematoma 4 5 3 4.2 0.236 0.134

Thromboembolism 0 0 0 0 0.000 1.000

Table 2: Comparison between manual and robotic groups as regards

complications.

Efficacy

Group C

(n = 40)

Group N

(n = 40)

Group R

(n = 70) X2 P

No % No % No %

Short term

Good (without AAD) 32 80 30 75 54 77.1 1.646 0.801

Average (with AAD) 4 10 4 10 10 14.3

Comprehensive success 36 90 34 85 64 91.4

Failure 4 10 6 10 6 8.6

Mid term

Good (without AAD) 30 75 32 80 58 82.9 2.161 0.706

Average (with AAD) 4 10 2 5 6 8.6

Comprehensive success 34 85 34 85 64 91.4

Failure 6 15 6 15 6 8.6

Long term

Good (without AAD) 30 75 32 80 60 85.7 3.014 0.555

Average ( with AAD) 2 5 2 5 4 5.7

Comprehensive success 32 80 34 85 64 91.4

Failure 8 20 6 15 6 8.6

Table 3: Comparison between the three groups as regards procedural efficacy

and success rate.

Citation: Samir Rafla, Mostafa Nawar, Amr Kamal, Josef Kautzner (2017). Robotic Ablation of Atrial Fibrillation Saves Time and Irradiation Dose

Page 4 of 5

Volume 1 • Issue 2 • 008 www.scientonline.org Ann clin Res Trials

Discussion

Catheter ablation of AF is now a realistic therapeutic option

for patients with paroxysmal AF. (9) In this study, one hundred and

fifty patients were enrolled for catheter ablation of symptomatic

paroxysmal AF who had failed at least one antiarrhythmic drug.

Multivariate analysis of predictors of success in Group

C (Carto)

In our study, a multivariate analysis of predictors of success

for patients with paroxysmal AF who underwent ablation using

Carto 3D EAM technology and manual ablation was done and

different variables were evaluated as regards their significance as

predictors of success.

The significant predictors of success in Carto group were PV

antral isolation as the used method of eliminating PV triggers,

PV antrum as a target PV ablation site, early recurrence during

blanking period, rhythm outcome, baseline ECG, duration of

AF and additional ablation line (roof line) in order, while other

predictors were not significant.

Zhong et al. [10] was very strict in conclusion and showed

that Carto Merge system is inaccurate and they suggested that

this inaccuracy may be reduced by using CT and electroanatomic

images obtained at the same point in the atrial mechanical

cycle. Accuracy was significantly improved when the end-atrial

contraction CT image was used for registration.

Multivariate analysis of predictors of success in NavX

(N) group

In our study, a multivariate analysis of predictors of success

for patients with paroxysmal AF who underwent ablation using

NavX 3D electroanatomic mapping (EAM) technology and

manual ablation was done and different variables were evaluated

as regards their significance as predictors of success.

The significant predictors of success in NavX manual group

were early recurrence during blanking period, rhythm outcome,

LV EF (systolic heart failure (HF), baseline ECG, test for AF

inducibility, additional ablation line (roof line), diabetes mellitus,

and hypertension in order, while other predictors were not

significant.

Multivariate analysis of predictors of success in Group

R (Robot)

In our study, a multivariate analysis of predictors of success

for patients with paroxysmal AF who underwent ablation using

NavX 3D EAM technology and Robotic ablation was done and

different variables were evaluated as regards their significance as

predictors of success.

The significant predictors of success in Robot group

were early recurrence of AF during blanking period, rhythm

outcome, LV EF, systolic HF, test of AF inducibility, baseline ECG,

hypertension and duration of AF in order, while other predictors

were not significant.

Robotic Catheter Navigation System

In the present study it was evident that the major advantage of

robotic navigation as compared to manual navigation is catheter

stability (Figures 2 and 3). It is obvious from our observations

that robotic navigation system is proved to be safe and feasible

with same has been proved on experimental studies [11,12] and

on early human experience reported in literature [8,13-17].

Owing to the precise catheter navigation in conjunction with

better catheter stability of the robotic navigation system, patients

in the robotic arm of this study needed less RF applications as

well as much less RF time, when compared to the other two

groups of manual ablation, and these findings was independent

on the type of the three dimensional LA map.

In our pooled data analysis, the total number of ablation

points was significantly higher in manual group (Carto and NavX)

(72.2 ± 29.4) compared to Robot group (49.9 ± 12.6). Moreover,

the total ablation time was significantly higher in manual group

(Carto and NavX) (2094.8 ± 911.7 seconds) compared to Robot

group (1323.1 ± 355.6 seconds).

Conclusions

The ideal ablation strategy for Atrial Fibrillation (AF) uses the

least amount of ablation needed to achieve the highest possible

Figure 2: Hansen Robotic System.

Figure 3: Comparison of efficacy between the three groups.

Citation: Samir Rafla, Mostafa Nawar, Amr Kamal, Josef Kautzner (2017). Robotic Ablation of Atrial Fibrillation Saves Time and Irradiation Dose

Page 5 of 5

Volume 1 • Issue 2 • 008 www.scientonline.org Ann clin Res Trials

success rate. Comparison of the manual groups (group C and

group N) showed that use of Carto technology was associated with

greater number of ablation points and longer total ablation time

for a comparable set of lesions, however this was not translated

into either a significant difference in procedural time or procedural

outcome and complications rate was comparable between the 2

groups with no significant difference. Robotic navigation system

could perform ablation procedures in a substantially equivalent

manner to conventional manually controlled catheters; however,

the remote robotic navigation system would be able to overcome

the limitations of manual control by combining the ease of

navigation with a readily available wide navigational field. In

addition, it will reduce the physician’s radiation exposure during

long procedures of electrophysiologic study and catheter ablation.

Remote robotic catheter navigation system can add

precise catheter control, stability and maneuverability to

electrophysiology mapping and ablation procedures. These

features, coupled with the added safety of IntelliSense and the

potential of lesion and map optimization using catheter tissue

interface pressure, make robotic catheter control an attractive

option for the modern EP lab.

Robotic ablation was associated with significantly lower

fluoroscopy exposure well as significantly shorter overall

procedure time.

Robotic ablation is as effective and safe as manual ablation

with very low procedural and post procedural complication rates.

References

1. Nair GM, Nery PB, Diwakaramenon S, Healey JS, Connolly SJ, Morillo CA.

A systematic review of randomized trials comparing radiofrequency ablation

with antiarrhythmic medications in patients with atrial fibrillation. J Cardiovasc

Electrophysiol. 2009;20(2):138-144.

2. Andrikopoulos G, Tzeis S, Maniadakis N, Mavrakis HE, Vardas PE. Costeffectiveness

of atrial fibrillation catheter ablation. Europace. 2009;11(2):147-151.

3. Forleo GB, Mantica M, De Luca L, et al. Catheter ablation of atrial fibrillation

in patients with diabetes mellitus type 2: results from a randomized study

comparing pulmonary vein isolation versus antiarrhythmic drug therapy. J

Cardiovasc Electrophysiol. 2009;20(1):22-28.

4. Kearney K, Stephenson R, Phan K, Chan WY, Huang MY, Yan TD. A

systematic review of surgical ablation versus catheter ablation for atrial

fibrillation. Ann Cardiothorac Surg. 2014;3(1):15-29.

5. Marrouche NF, Martin DO, Wazni O, et al. Phased-array intracardiac

echocardiography monitoring during pulmonary vein isolation in patients

with atrial fibrillation: impact on outcome and complications. Circulation.

2003;107(21):2710-2716.

6. Ouyang F, Bänsch D, Ernst S, et al. Complete isolation of left atrium surrounding

the pulmonary veins: new insights from the double-Lasso technique in

paroxysmal atrial fibrillation. Circulation. 2004;110(15):2090-2096.

7. Pappone C, Rosanio S, Augello G, et al. Mortality, morbidity and quality of life

after circumferential pulmonary vein ablation for atrial fibrillation: outcomes

from a controlled nonrandomized long-term study. J Am Coll Cardiol.

2003;42(2):185-197.

8. Saliba W, Reddy VY, Wazni O, et al. Atrial fibrillation ablation using a robotic

catheter remote control system: initial human experience and long-term

follow-up results. JACC. 2008;51(25):2407-2411.

9. Natale A, Raviele A, Arentz T, et al. Venice chart international consensus

document on atrial fibrillation ablation. J Cardiovasc Electrophysiol.

2007;18(5): 560-580.

10. Edward P. Gerstenfeld, William Sauer, David J. Callans,et al. Predictors of

success after selective pulmonary vein isolation of arrhythmogenic pulmonary

veins for treatment of atrial fibrillation. Heart Rhythm. 2006:3(2):165-170.

11. Saliba W, Cummings JE, Oh S, et al. Novel robotic catheter remote control

system: feasibility and safety of transseptal puncture and endocardial catheter

navigation. J Cardiovasc Electrophysiol. 2006;17(10):1102-1105.

12. Reddy VY1, Neuzil P, Malchano ZJ, et al. View-Synchronized Robotic Image-

Guided Therapy for Atrial Fibrillation Ablation Experimental Validation and

Clinical Feasibility. Circulation. 2007;115(21):2705-2714.

13. Schmidt B, Tilz RR, Neven K, Chun J, Fuernkranz A, Ouyang F. Remote robotic

navigation and electroanatomical mapping for ablation of atrial fibrillationconsiderations

for navigation and impact on procedural outcome. Circ Arrhythmia

Electrophysiol. 2009:2(2);120-128.

14. Kautzner J, Peichl P, Cihák R, Wichterle D, Mlcochová H. Early experience

with robotic navigation for catheter ablation of paroxysmal atrial fibrillation.

Pacing Clin Electrophysiol. 2009;32(Suppl 1): S163-S166.

15. Luigi Di Biase, Yan Wang, Rodney Horton, et al. Ablation of Atrial Fibrillation

Utilizing Robotic Catheter Navigation in Comparison to Manual Navigation

and Ablation: Single-Center Experience. J Cardiovasc Electrophysiol.

2009;20(12):1328-1335.

16. Arbelo E, Brugada J, Hindricks G, et al. on the behalf of the Atrial Fibrillation

Ablation Pilot Study Investigators. (2014) The Atrial Fibrillation Ablation Pilot

Study: an European Survey on Methodology and Results of Catheter Ablation

for Atrial Fibrillation: conducted by the European Heart Rhythm Association.

Eur Heart J. 2014;35(22):1466-1478.

17. Bai R, DI Biase L, Valderrabano M, et al. Worldwide experience with the

robotic navigation system in catheter ablation of atrial fibrillation: methodology,

efficacy and safety. J Cardiovasc Electrophysiol. 2012;23(8):820-826.

Copyright: © 2017 Samir Rafla, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits

unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

December 2017
89 Reads

Similar Publications