Surgical treatment of atrial fibrillation using radiofrequency ablation

(1)

UvA-DARE is a service provided by the library of the University of Amsterdam (http

s

://dare.uva.nl)

UvA-DARE (Digital Academic Repository)

Khargi, K.

Publication date

2005

Link to publication

Citation for published version (APA):

Khargi, K. (2005). Surgical treatment of atrial fibrillation using radiofrequency ablation.

General rights

It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s)

and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open

content license (like Creative Commons).

Disclaimer/Complaints regulations

If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please

let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material

inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter

to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You

will be contacted as soon as possible.

(2)

C H A P T E R 5

Irrigated radiofrequency ablation is a safe and

effective technique to treat chronic atrial fibrillation;

a cohort study comprising 124 consecutive patients

8

'

9 Krishna Khargi', Thomas Deneke", Frank Kuschkowitz', Helmut Haardt",

Klaus-Michael Muller"", Bernd Lemke", Axel Laczkovics'.

8 Presented, in part, at the Annual Techno-College of the European Association for Cardio-Thoracic Surgery (EACTS),

20-21 June 2002, Monte Carlo, Monaco

v Published in part in Interactive Cardiovascular and Thoracic surgery (ICVTS) 2003; 2: 241-5.

* Department ofCardiothoracic Surgery, Berufsgenossenschaftliche Kliniken Bergmannsheil-University Hospital Bochum, Germany. * Department of Cardiology, Berufsgenossenschaftliche Kliniken Bergmannsheil- University Hospital Bochum, Germany.

(3)

IRRIGATED RADIOFREQUENCY ABLATION IS A SAFE AND EFFECTIVE TECHNIQUE TO TREAT CHRONIC ATRIAL FIBRILLATION; A C O H O R T STUDY COMPRISING 124 CONSECUTIVE PATIENTS

J&ii]

ELSEVIER

Interactive Cardiovascular and Thoracic Surgery 2 (2003) 241-245

INTERACTIVE CARDIOVASCULAR AND

THORACIC SURGERY

Work in progress report - Arrhythmia

Irrigated radiofrequency ablation is a safe and effective technique to treat

chronic atrial fibrillation

v

Krishna K h a r g r ' *

1

, Thomas Deneke

b

, Bernd Lemke

b

, Axel Laczkovics

a

'Department ofCardiotlwracie Surgery: Beritfsgenossenschaflliche KUrUken Bergmannsheil-University Hospital, Bochttm, Germany department cf Cardiology, Beritfsgenossenschaflliche Kliniken Bergmannskeil-University Hospital, Bochum, Germany

Received 21 October 2(H)2; received in revised form 5 February 2003; accepted 7 February 2003

Objective: The safety of intraoperative non-irrigated temperature-control led radiofrequency ablation to treat atrial fibrillation is a matter

of debate. This study evaluates a different operative technique using saline-irrigated-eooled-tip radiofrequency ablation (SICTRA) to treat atrial fibrillation. Patients a n d methods: One hundred and twenty-four concomitant anti-arrhythmic procedures, using SICTRA were performed: 113 to treat chronic AF ( > 6 months) and 11 lo cure paroxysmal AF. Results: Twenty-eight MVP. 42 MVR. 17 AVR and six double valve procedures with or without CABG, one ASD closure and 30 solitary CABG were performed. The mean (S.D.) left atrial diameter, preoperative duration of AF. aortic cross-clamp time were 50.5 mm (9.8), 57 months (64) and 99 min (21). Thirty day mortality was 4.8% (6/124; euroscore 17. 11. 8. 8. 6. 5). Autopsies did not reveal any esophageal, pulmonary orifice, or circumflex artery injuries. No ablation related bleeding was observed. Mean follow-up (S.D.) was 19.7 months (14.4). Fourteen patients died during follow-up. The cumulative postoperative SR at 6 and 12 months was 607c and 70%. The cumulative survival at 1 and 2 years was 8 6 % and 8 3 % . Conclusion: Irrigated radiofrequency ablation was effective. It was not associated with procedural complications in our series.

Keywords: Arrhythmia; Eleclrophysiology; Radiofrequency ablation: Atrial fibrillation; Esophageal injury: Circumflex artery injury; Mitral valve surgery;

CABG

1. I n t r o d u c t i o n 2. P a t i e n t s a n d m e t h o d s

T h e o p e r a t i v e t e c h n i q u e u s i n g a t e m p e r a t u r e - c o n t r o l l e d , n o n - i r r i g a t e d r a d i o f r e q u e n c y a b l a t i o n to treat atrial fibrillat i o n h a s b e e n r e p o r fibrillat e d fibrillato b e a s s o c i a fibrillat e d w i fibrillat h a fibrillat r i o -e s o s p h a g -e a l a n d c i r c u m f l -e x a r t -e r y injuri-es [ 1 . 2 , 3 ] . In o u r c e n t e r a different t y p e of e n e r g y s o u r c e , as p r o p o s e d by Sie a n d c o l l e a g u e s | 4 | , w a s u s e d t o treat atrial fibrillation, n a m e l y the s a l i n e - i r r i g a t e d , c o o l e d - t i p r a d i o f r e q u e n c y a b l a t i o n ( S I C T R A ) . T h i s s t u d y e v a l u a t e s the safety a n d e f f e c t i v e n e s s of S I C T R A .

Presented at the Annual Techno-College in association with the European Association for Curdio-thoracic Surgery. Monte Carlo. Monaco. September 21.2002.

* Corresponding author. Tel.: +3026006: fax: + 49-234-3026010.

E-mail address: krishna.khargi@ruhr-uni-bochum.de (K. Khargi I.

1 Krishna Khargi. author of ihis manuscript, has an education and training agreement on the surgical treatment of alrial fibrillation with Medtronic Europe SA. since 15 November 2001.

B e t w e e n April 1997 a n d M a r c h 2 0 0 2 , 113 v a l v e a n d / o r C A B G patients with c h r o n i c A F , p r e e x i s t i n g l o n g e r than 6 m o n t h s , a n d 1 1 p a t i e n t s w i t h p a r o x y s m a l A F h a d a c o n c o m i t a n t a n t i - a r r h y t h m i c s u r g e r y . E a c h p a t i e n t h a d a p r e o p e r a t i v e s t a n d a r d E C G . a 24-h Holter registration a n d a t r a n s t h o r a c i c e c h o c a r d i o g r a p h y . O n a d m i s s i o n to o u r h o s p i t a l , e a c h patient h a d an e x t e n d e d E C G r e c o r d i n g of the V 2 a n d II leads. If an e p i s o d e of s a w - t o o t h e d atrial w a v e pattern o r an e p i s o d e of regularity w a s o b s e r v e d on this r e c o r d i n g , then a bi-atrial S I C T R A lesion pattern w a s c o n d u c t e d . O t h e r w i s e a left atrial lesion pattern w a s p e r f o r m e d only. All patients w i t h p a r o x y s m a l A F had a sole left atrial lesion pattern. Our t e c h n i q u e has been previously described 15,6].

2.1. Postoperative care

P a t i e n t s w e r e kept o n A A I o r D D D p a c i n g if the heart rate w a s b e l o w 7 5 b p m d u r i n g the first 7 p o s t o p e r a t i v e d a y s . T h e first 2 8 p a t i e n t s r e c e i v e d m e t o p r o l o l 4 0 m g t w i c e a d a y o n

(4)

CHAPTER 5

K. Khargi et al. /Interactive Cardiovascular and Thoracic Surgery 2 (2001) 241-245

the 1st postoperative day (pod). 80 mg twice a day on the 2nd

pod and 160 mg twice a day after the 7th pod. This medication

protocol was changed after the 28th patient, because two

patients experienced a sudden cardiac death during follow-up.

We changed to metoprolol 47.5 mg per day starting on the 1st

pod. The dose was increased to 95 mg retard per day on the 3rd

postoperative day and eventually to 190 mg per day if no

hradyarrhythmia was noticed. The first 50 patients had a

cardioversion at the 12th pod and the 3rd postoperative month.

However, this strategy was abandoned because no beneficial

effect, in our opinion, was noticed. Therefore, no

cardiover-sion was performed before the 6th postoperative month in the

last 74 patients. If the patient remained in AF after the 6th

postoperative month, than one cardioversion with 240-360 J

was performed. All patients received coumadine. starting on

the 1st pod. targeting an INR value around 2.2 for solitary

CABG patients and 2.8-3.2 for valve patients.

2.2. Follow-up

Data acquisition was obtained for each patient on the 1st

pod, 12th pod (pre-discharge) and after the 3rd. 6th. 9th. 12th

and 24th postoperative month. The medical history, clinical

examination and an electrocardiogram (ECG) were obtained

at each visit. A 24-h ECG analysis was performed after 3,6 and

12 months. A transthoracic echocardiography, including

transmittal and transtricuspidal Doppler examination, was

obtained on the 12th pod, after 3, 6 and 12 months. Survival

information was complete. Continuous variables were

expressed as mean with standard deviation. The survival rate

was calculated according to the Kaplan-Meier method. The

cumulative postoperative SR rate was calculated.

.3. Results

Patients with chronic AF (n = 113) had a mean (S.D.)

age, euroscore, duration of preoperative AF, left atrial

diameter (S.D.), left ventricular ejection fraction of 66.3

years (10.2), 6.4 euroscore (3.1). 57 months (64), 50.0 mm

(9.8), 58% 114]. The operative data of all 124 patients are

shown in Table I. A left atrial lesion pattern was performed

in 55 patients, while 69 patients had a bi-atrial lesion

Table 2

Thirty-day mortality (;i =6)"

Table 1 Operative dala^ MVR + TVP MVR + CABG MVP MVP + CABG AVR AVR + CABG CABG MVR + AVR MVR + AVR + other Other

E.C.C. time, min (S.D.) AoX time, min (S.D.)

35 7 15 13 15 164(36) 99 (22)

'' Abbreviations: MVR. mitrai valve replacement; MVP. mitral valve plasty: AVR. aortic valve replacement; E.C.C. exlra corporeal circulation; AoX. aortic cross-clamp time.

pattern. Our 30-day mortality was 4.8% (6/124), as shown in

Table 2. At autopsies no esophageal, pulmonary orifice or

circumflex artery injuries were observed.

Postoperative complications included a transient low cardiac

output 3.2% (4/124), pulmonary infection or atelectasis 6.5%

(8/124), pneumothorax with drainage 1.6% (2/124), sternal

dehiscence4.0% (5/124), IABP0.8% (1/124), transient ischemic

neurological attack 0.8 (1/124). Postoperative bleeding occurred

in 3.2% (4/124). The bleeding sites were a right atrial suture

line (n = 2), a venous canulation site and a left auricle wall

artery. During follow-up 14 patients died, as shown in Table 3.

The overall cumulative postoperative SR rate is shown in

Fig. I.

Fig. 2 provides the cumulative SR rates of patients with

preexisting chronic AF analyzed according to the bi-atrial

in = 69) and left atrial (n = 44) lesion pattern.

All 11 patients with paroxysmal AF were in SR during

their evaluation visits.

At 3 months 64 patients showed a stable SR. defined as

95-100% SR at Holter ECG. A bi-atrial contraction was

observed in 44 (69%) patients, a right atrial contraction in 14

patients (22%), no atrial contraction in six (9%) patients. At 6

months 72 patients were in a stable SR, defined as 95-100%

SR at 24-h Holter ECG. A bi-atrial contraction was observed

in 61 (85%) patients, a right atrial contraction in eight (11%)

patients, no atrial contraction in three (4%) patients. At 12

months 74 patients were in SR with similar distribution.

Pi EG I.W AH HA SVV WH Age 67 63 78 66 73 71 (years) Euro 5 8 8 17 II 6 I.VKFW) 25 15 50 38 15 75 Type of AF Chronic Paroxysmal Chronic Chronic Chronic Chronic Operalion AVR + CABG AVR 1 MVP i- TVP + CABG AVR MVP -1- CABG CABG MVR + CABG Cause of death Low cardiac output Low cardiac output Low cardiac output Cardiac failure Cerebral stroke Atrioventricular dehiscence '' Abbreviations: MVR. mitral

entricular ejection fraction.

(5)

IRRIGATED RADIOFREQUENCY ABLATION IS A SAFE AND EFFECTIVE TECHNIQUE TO TREAT CHRONIC ATRIAL FIBRILLATION; A COHORT STUDY COMPRISING 124 CONSECUTIVE PATIENTS

K- Khargi et ul. / Intern • Cardiovascular and Thoracic Surgery 2 (2003) 241-245

Table 3 Death din PI BW r,F. KW NH BF. DA K.I RF .IF. PF. I)H SK MW RO " Abbn uig follow-up"1 Age (y 67 7.1 7.1 56 75 49 75 74 80 74 70 59 73 61 viations:

4. Discussion

4.1.

Morbidity ars) MVR LVEF(%) 35 S3 60 65 65 56 55 85 40 70 6(1 60 60 60 mitral valve repla

Operation MVR + CABG MVR + CABG MVR CABG MVR + CABG MVR MVR + CABG AVR AVR AVR MVR MVR CABG MVR

cement: AVR. aortic Rhylh SR SR AF SR SR SR SR SR SR SR SR SR llulte AF valve repla

m Cause of death Follow-up (months)

Cardiac failure 1.2 Gastrointestinal bleeding with gastrectomy 1.3

Sudden cardiac death 1.5 Cerebral stroke 1.6 Mediastinits 2.0 Renal bleeding. Nephrectomy 2.5

Mediastinits 2.6 F.ndocardilis 4.0 COPD 4.3 Sudden Cardiac death 5.0

COPD 8.9 COPD 15.7 Unknown 22.5 COPD 32.8 cement: Pi. patient's initials: LVEF, left ventricular ejection fraction.

ablation devices and lesion patterns can be distinguished.

Mohr performed 133 right lateral minithoracotomies,

whereas all our patients had a standard sternotomy. We

In our series the incidence of postoperative complications were within the expected range. Postoperative bleeding was never related to a radiofrequency ablation line. During follow-up not a single patient showed signs or symptoms, which were associated with an esophageal or circumflex artery or pulmonary vein orilice injury. In contrast, Mohr and associates, who surgically treated atrial fibrillation in 234 patients, reported an incidence of an atrio—esophageal fistula in 1.3 ''/<• (3/234) and a circumflex artery stenosis in 0.4% (1/234) [1]. Gillinov and colleagues reported a fatal esophageal injury in a cachectic female patient [3J.

A clear explanation for the discrepancy in observation of esophageal and circumflex injuries in our series and that from Mohr, Gillinov and colleagues cannot be provided. Nevertheless, important differences in operative techniques,

dissected the left atrium free from its adjacent structures before the ablation was started. The left atrial roof was freed from the right pulmonary artery and the superior caval vein. The transverse and oblique sinuses were opened. Therefore, the heart was fully mobilized within its pericardial sac. Mohr used a 10-mm T-shaped, temperature-controlled, non-irrigated radiofrequency ablation probe targeting a tem-perature of 60 °C for 20 s for each lesion without taking the variability of the local atrial wall thickness into account. The probe was fixed and pressed against the atrial wall during the application [6J. Gillinov used an even higher temperature (80 °C) and a longer application time (60 s) |3], We used a SICTRA catheter, which was a hand-held, flexible, pen-catheter that enabled the surgeon to match the delivered amount of radiofrequency energy to the estimated atrial wall thickness, creating a conduction block without

Cumulative SR Rate

n=113

CD CO

GC

-.9. ,8-,7. ,6. . 5 . . 4 -,3'

1

0.70 (0.045) I

I

.2 J f 0.60 10.047) . 1 .

1,0 1 Standard error in brackets ()

10 15 20 25 30 35 40 45 50 55 60 65 70 Patients 'Out of SR" rt= 41 23 15

Follow-up (Months)

(6)

CHAPTER 5

K. Khargi el til. / Interactive CardJavasada ui Thor, i- 2 I20ll.il 241-245

Cumulative SR Rate

Biatrial (n=69) versus left atrial ( n=44) lesion pattern

f0.71 (0.057)

0.69(0.073)

Standard error in brackets ()

Number of patients „out of SR" - Bi-atrial 42 23 13 9

i Left Atrial 25 19 10 3 Follow-up ( Months)

Fig. 2. Postoperative enmnlalh

in = 44) lesion pattern. (K-axis

! frequenci enmulativi

:s of SR in patients with a preexisting chronic AF. analyzed aeeording to the bi-atrial in = 69) and left atrial frequency of SR: X-axis, postoperative months).

any tissue dehiscence. The formation of yellow-white blistering endocard lesions, induced by oscillating catheter movements, was considered sufficient. Stable catheter-tissue contact was preserved without pressing the atrial wall against adjacent mediastinal structures. We performed circumferential lesions around each pulmonary vein orifice, without ever entering any of these orifices. The left auricle was always resected or closed from inside.

Williams and colleagues used a flexible, temperature-controlled radiofrequency ablation catheter in 48 patients. In contrast to the series of Mohr and associates a standard sternotomy was always performed | 7 | . Although Williams targeted a higher temperature level, 7 0 - 8 0 °C, and a longer application time of l min per lesion than Mohr and associates did, they did not report any esophageal or circumflex injuries, nor did Benussi. Melo. Sie and colleagues [4.8.9J.

4.2. Mortality

No mortality was observed in the subset patients group who had mitral valve surgery alone. Indication and selection in high risk patients, necessitating combined surgical procedures, should be tailored carefully, since an increase of the postoperative morbidity and mortality can be anticipated. Nevertheless, the potential benefit of restoring SR with atrial contraction in high-risk patients can be significant because an improved left ventricular diastolic volume filling can be expected.

Since the occurrence of two sudden cardiac deaths (patients K.W.. P.E.), our postoperative medication was changed from sotalol to metoprolol. We felt that brady-arrhythmias. induced by sotalol, could be the cause of death, although no clear documented evidence was available. However, up until now none of the metoprolol patients experienced any sudden cardiac death.

4.3. Sinus rhythm

In our series, the cumulative postoperative SR rate at 6 and 12 months was 60% and 70%. Our series includes patients with chronic atrial fibrillation with a mean duration of 57 months. All our patients had a concomitant valve and/or CABG procedure. Atrial fibrillation was never the primary indication for operation. Patients with parox-ysmal AF were excluded from our analysis. Therefore, our group of patients is not similar lo those reported by Cox, Schaff and Millar and associates 110.11.12].

Our observed postoperative SR rate is consistent with publications of Mohr, Benussi. Williams and Sie. who reported a SR rate between 66.7% and 8 1 % .

The gradual increase of the SR conversion rate in our series, starting from 32% immediate postoperatively to 70% after 12 months is consistent with our previous observations [5,6). Cox also described the occurrence of AF in the early postoperative period in 47% of his patients. This was related to the temporarily shortened refractory time during the early weeks postoperatively. In addition to that. Pasic and colleagues reported that the improvement of the sinus node function and atrial contraction was related to the functional reinnervation and recovery of the autonomic nervous system, which could take up to 1 year after operation [13,14],

4.4. Failures

At6 months 34 patients remained in AF. Cardioversion was successful, determined as SR at next follow-up visit in only two patients. The actual failure rate in our series was 32% (36/113):aflutterin3.5<7, (4/113) and atrial fibrillation in 28% (32/113). Two potential causes of these failures should be considered: (1) a non-transmural intra-atrial lesion due to an inadequate ablation line; and (2) an inadequate lesion pattern.

(7)

IRRIGATED RADIOFREQUENCY ABLATION IS A SAFE AND EFFECTIVE T E C H N I Q U E TO TREAT CHRONIC ATRIAL FIBRILLATION; A C O H O R T STUDY COMPRISING 124 CONSECUTIVE PATIENTS

K. Khargi et at. / Interactive Cardiovast

The atrial flutter may have two important origins: the isthmus in the right atrium or a preserved conduction line between the left and right atrium through the coronary sinus. Three patients needed a percutaneous arrhythmia corrective reintervention because of a right atrial flutter (n = 2) and a left atrial flutter

(n = 1). The right atrial flutters could be ablated successfully,

while the left atrial flutter was treated with AV node ablation and DDD pacemaker implantation.

In summary, a concomitant anti-arrhythmic surgical procedure using SICTRA obviously extended the operative procedure, however, without inducing any disproportionate morbidity or mortality. SICTRA resulted in a significant SR conversion rate in our series, which consisted of high-risk patients with a mean euroscore of 6.4, in whom curative treatment of chronic AF was a challenging objective. No SICTRA procedural complications were observed.

Acknowledgements

The cooperation and support of Frank Kuschkowitz, cardiothoracic surgical resident. Helmut Haardt. perfusio-nist and Klaus-Michael Muller pathologist is greatly appreciated.

References

|1J MohrFW. Fabricius A. Falk V. Autschbach R. Doll N. von Oppel U. Diegeler U. Kotikainp H. Hindricks G. Curative treatment of atrial fibrillation with intraoperative radiofrequency ablation: short term and midterm results. J Thorae Cardiovase Surg 2002;(123):919-27. |2] Pathwardhan A, LadVS.Pai V. Esophageal injury during radiofrequency

ablation for atrial fibrillation: inherent safety of radiofrequency bipolar coagulation. J Thorae Cardiovase Surg 2002:124:642-3.

[3] GilHnov M, Peterson G. Rice Th. Esophageal injury during radiofrequency ablation for atrial fibrillation. J Thorae Cardiovase Surg 2001;(122(6):1239-4O.

[4| Sie HT. Beukema WP. Ramdat Misier A. Elvan A. Ennema JJ. Haalcbos MMP. Wellens HJJ. The radiofrequency modified maze in patients undergoing concomitant cardiac surgery. J Thorae Cardio-vase Surg 2001:122:249-55.

15] Deneke Th. Khargi K, Grewc PH. Laczkovics A. von Dryander S. Lawo Th, Mueller KM. Lemkc B. Efficacy of an additional Maze procedure using cooled tip radiofrequency ablation in patients with chronic atrial fibrillation and mitral valve disease: a randomized trial. Eur Heart J 2002:23:558-66.

161 Khargi K. Deneke Th. Haardt H. Grewe P. Muller KM. Laczkovics A, Lemkc B. Saline irrigated, coofed-tip radiofrequency ablation is an effective technique to perform the maze procedure. Ann Thorae Surg 2001 ;72:S 1090-5.

[7] Williams MR. Stewart JR. Boiling SF. Freeman S. Anderson JT. Argenziano M. Smith CR. Oz MC. Surgical treatment of atrial fibrillation using radiofrequency energy. Ann Thorae Surg 2001;71:1939-43. |8J Benussi S, Pappone C. Nascimbene S. Oreto G. Caldarola A. Stefano

PL, Casati V. Allien O. A simple way to treat chronic atrial fibrillation during mitral valve surgery: the epicardial radiofrequency approach. Eur J Cardiothorac Surg 2001;19:231-4.

19| Melo J. Adragao P. Neves J. Ferrcira M. Timoteo A. Santiago T. Ribeiras R. Canada M. Endocardial and epicardial radiofrequency

utar and Thoracic Surgery 2 (2003) 241-245 245

ablation in the treatment of atrial fibrillation with a new intraoperative device. Eur J Cardiothorac Surg 2000:18:182-6.

[ 10] Cox JL. The surgical treatment of atrial fibrillation. The gold standard: long term results from the maze procedure. Second annual conference on the surgical treatment of atrial fibrillation. June 19-20. 2002. New York (Abstract),

111] Schafl' HV. Dearani JA, Daly RC, Orszulak TA. Danielson GK. Cox-Maze procedure for atrial fibrillation: Mayo Clinic experience. Semin Thorae Cardiovase Surg 2000;12:30-7.

112] Millar RC. Arcidi JM. Alison PJ. The maze III procedure for atrial fibrillation: should the indication be expanded. Ann Thorae Surg 2000:70:1580-6.

[13{ Cox J. Boineau JP. Schuessler RB. Kater KM. Lappas DG. Five year experience with the maze procedure for atrial fibrillation. Ann Thorae Surg 1993:56:814-24.

114] PasicM.Musci M. Siniawski H. Grauhan O, Edelmann B. TcdoriyaT. Weng Y, Heizer R. The Cox-Maze III procedure: parallel normalization of the sinus node dysfunction, improvement of the atrial function and recovery of the cardiac autonomic nervous system. J Thorae Cardiovase Surg 1999;! 18:287-88.

Appendix A. ICVTS on-line discussion

Author: Leo Bockeria, Bakoulev Center for Cardiovascular Surgery,

135 Roublevskoye slwsse. Moscow 121552, Russian Federation

Date: l()-Jun-2003 15:06

Message: I have read the paper with great interest and would like to congratulate the excellent results of surgical treatment of chronic AF using SICTRA technique in patients with concomitant valve and/or CABG procedure. Complications and deaths occurred in the group of the most severe patients. The present method is especially useful for patients having mitral valve surgery alone, or combined with aortic valve replacement while using minimal invasive surgery when Maze III procedure is technically impossible.

It is doubtless thai for different groups of researchers the studied groups of patients differ noticeably. This is especially true about electrophysiological properties of the atria, the length of the history of paroxysms of AF and their transfer into chronic AF. anatomy of the left atrium, the degree of straining of the posterior wall of the left atrium and the degree of fibrosis in atria.

It is difficult to expect excellent results in the group of patients having advanced mitral valve stenosis, long history of atrial tachycardia, as well as advanced atrial dilatation and cardiomyopathy, if both Maze procedure removal of appendage of left atrium and plication of a left posterior wall and left and right isthmus blocks are not used.

In the Bakoulev Institute for Cardiovascular Surgery one of us (L.A. Bockeria) has been treating AF surgically since the middle of the 1980s. starting with the cryosurgical ablation of the austia of pulmonary vein and isolation of left atrium, advancing to Maze procedure and its modification (total 188 pts). Starting in 1992. patients with paroxysmal AF had Maze procedure. This procedure has been later modified at our institute. We started using a combination of laser fotoablalion orcrioablation in the left atrium and near the atrioventricular rings and surgical dissection in the right atrium and atria appendages. The best results (877r of SR and 82% of preservation of atria transport function) were received in the group of middle-aged patients having AF {34 pts). At present, patients with AF have bilateral isolation of pulmonary vein and left isthmus block. Patients with chronic AF (6 months and more) having enlargement of atria have a modified Maze procedure with and plication of a left atrium posterior wall and left isthmus block. We have used cooled RFA for open heart surgery since 1997. However, because of different thickness of the atrial wall in various zones, we have to use additional cryosurgical ablation in critical zones. Like you we have had no complications connected with cooled RFA. We believe, that patients having severe atrial hypertrophy can not be treated with conventional RFA. while cooled RFA in these cases must also be supplemented by cryoablalion in critical zones.