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Ann Thorac Surg 2001;71:1939-1944
© 2001 The Society of Thoracic Surgeons
a Division of Cardiothoracic Surgery, College of Physicians and Surgeons, Columbia University, New York, New York, USA
b Penrose Hospital, Colorado Springs, Colorado, USA
c Division of Cardiothoracic Surgery, University of Michigan, Ann Arbor, Michigan, USA
Address reprint requests to Dr Williams, College of Physicians and Surgeons, P&S 17-401, 630 West 168 St, New York, NY 10032
e-mail: mw365{at}columbia.edu
Presented at the Forty-seventh Annual Meeting of the Southern Thoracic Surgical Association, Marco Island, FL, Nov 9–11, 2000.
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Abstract |
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Methods. Endocardial pulmonary venous isolation was performed on 48 patients with AF undergoing concurrent operation using temperature-controlled radiofrequency energy delivered through a hand-held flexible probe. Additional right-sided lesions were made at the surgeon’s discretion.
Results. Forty-two patients were appropriate for analysis (6 died). These patients had an AF duration of 4.8 ± 6.4 years. At a mean follow-up of 138 ± 96 days, 34 patients were in sinus rhythm. We were unable to demonstrate a difference in outcome based on AF duration, left atrial size, or addition of right-sided lesions.
Conclusions. Radiofrequency atrial ablation was effective in 81% of patients with AF at restoring sinus rhythm at an average follow-up of 4 months. This procedure is simple to perform and should broaden the number of patients that receive an AF treatment procedure during concurrent cardiac operation.
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Introduction |
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In 1991, Dr James Cox and associates [2] described the Maze procedure, which was the end product of extensive animal and clinical experience [3, 4]. Nearly 10 years after its description, the Maze III procedure has the best reported success for any corrective treatment of AF [5]. Despite this success, the Maze procedure is not usually applied even for patients already requiring open heart procedures. The cause of this reluctance by cardiologists and surgeons is severalfold but includes concern for increased bypass and cross-clamp times, bleeding from the multiple suture lines, and technical difficulty, as well as unfamiliarity with the procedure. In an effort to lessen the technical concerns with the procedure we and other researchers have used a variety of sources to create similar lesions without the need for atrial incisions [6–8]. There are new data from clinical and laboratory investigations that suggest AF may originate from a source near or within the pulmonary veins [9] or be caused by a microreentry circuit anchored near the pulmonary veins inducing fibrillatory conduction [10]. This raises the possibility of doing a limited procedure in only the left atrium. This option is particularly attractive in patients undergoing mitral valve operation who have a high incidence of AF but would not normally require a procedure in the right atrium. Some investigators believe that a limited procedure will allow for better contractile function.
Herein we describe the use of radiofrequency energy to create lesions in lieu of incisions for atrial ablation with the intention of eradicating AF in patients undergoing concurrent cardiac operation.
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Material and methods |
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Procedure
All patients received linear radiofrequency ablation with a Food and Drug Administration-approved surgical probe (Cobra, Boston Scientific-EP Technologies, San Jose, CA) and surgical radiofrequency generator (Cobra ESU, Boston Scientific-EP Technologies). The surgical probe is flexible with seven available electrodes that are in close enough proximity that continuous linear lesions are created. Each electrode can be selectively turned on or off depending on the length and location of the desired lesion. Each electrode is independently regulated by the generator and contains two thermocouples 180 degrees apart. Each electrode is turned on and off multiple times a second to maintain the temperature within a narrow band of the set temperature. The generator supplied temperature-controlled radiofrequency at 70° to 80°C for 1 minute with a maximal power output of 150 W.
Lesions were made at the discretion of the surgeon, but all included isolation of the pulmonary veins either with one circumferential island (like the Maze III) or with separate right- and left-sided pulmonary vein lesions. In the case of a direct left atriotomy, the incision served as the lesion for the anterior side of the right pulmonary veins. All patients also underwent anatomic and electrophysiologic exclusion of the left atrial appendage, which was either accomplished by amputating the appendage or creating a circumferential radiofrequency lesion around its base and oversewing the orifice. The decision to perform right-sided lesions was dependent on the planned procedures and the surgeon’s preference. In some cases a Maze III was performed with radiofrequency lesions substituted for incisions.
Before the procedure the left atrial dimensions were noted on the intraoperative transesophageal echocardiogram.
Postoperative protocol
Patients did not receive any prophylactic class I or III antiarrhythmic medications. If AF reoccurred, these patients were treated with low dose amiodarone as tolerated. Amiodarone was generally discontinued after 4 weeks unless the primary cardiologist desired continued use.
Anticoagulation was at the discretion of the cardiologist, but it was recommended for 3 months if not otherwise required (ie, mechanical valve, persistent AF).
Patients were followed at regular intervals both by direct contact and through discussions and records of referring physicians.
Statistics
Discrete variables were compared using Student’s t tests and outcome measures compared using 
2 analysis. Multivariable analysis was not performed. A p value less than 0.05 was considered significant.
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Results |
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AF duration
Because new onset AF with concurrent mitral valve disease is frequently addressed by simply correcting the mitral valve disease, we undertook an analysis of a subset of patients who had AF present for at least 6 months before operation. There were 34 patients with a mean follow-up of 127 ± 84 days. At most recent follow-up, 26 (76%) patients were in sinus rhythm, slightly fewer than the entire population (81%) (p = not significant). More important, all of the failures for the entire population were in this group of patients with AF for more that 6 months. Of those patients with AF for less than 6 months (n = 8), only 2 were discharged in AF but were in sinus rhythm at follow-up (both on amiodarone).
Left atrial size
Some researchers have suggested that success is dependent on left atrial size [6]. We were unable to demonstrate a difference in left atrial size based on intraoperative transesophageal echocardiogram measurements between those in sinus rhythm and those with a failed procedure (6.0 ± 1.5 cm versus 6.4 ± 1.7cm, p = not significant). Additional analyses stratifying patients based on large atrium (> 6 cm or > 7 cm) revealed no difference.
Left-sided versus right-sided procedure
Many proponents of the Maze III procedure would argue that AF is a left-sided phenomenon and AFl is a right-sided one. Thus, if only a left-sided procedure is performed, then there will be a greater incidence of AFl and perhaps a higher AF rate. We performed a subanalysis of patients having left-sided only compared to left- and right-sided procedures. We were unable to find a difference in successful outcome between those with and without right-sided lesions (87% versus 79%, p = not significant), but the number with right-sided lesions is small (n = 8). The lack of a difference persisted even when people with AF less than 6 months were excluded. Three of those with right-sided lesions had the lesion set described by the Maze III and the others had modifications that included a flutter lesion to the tricuspid annulus. Those receiving the traditional Maze lesions are all in sinus rhythm.
Of those receiving left-sided lesions 7 patients had at least one episode of AFl and 2 remain in AFl at the most recent follow-up. Frequently we found that AFl occurred in patients with perioperative AF started on amiodarone before conversion to a normal rhythm.
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Comment |
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The radiofrequency procedures appeared reasonably effective with a success rate of 76% to 81% that parallels similar procedures [11–13]. These results, however, are not as good as those reported by Cox and some others performing the Maze III procedure [5, 14]. However, the largest reported experience of 686 patients having concurrent Maze III/mitral valve procedure describes a success of 76% among survivors, which was not significantly different than any of the other related procedures studied including left-sided only approaches [15].
We were concerned about the high mortality in this study. We removed these patients from our analysis to evaluate subtle aspects of the procedure. If the patients that died are included in the analysis as failures, the success rate of the procedure would be 71%, which is still comparable to similar work. We were unable to correlate our mortality with the ablative treatments. The only argument for the procedure contributing to mortality would be the added cross-clamp and bypass times from the procedure, although these are usually minimal.
The benefit of using radiofrequency ablation in patients with short duration AF is unclear. If these patients are excluded, the results remain acceptable and better than would be expected if there had been no AF intervention. There has been a trend in the past several years to operate on patients with mitral valve disease earlier and new onset AF in these patients is often used as an indication for operation. Surgical intervention to correct only the valve disease provides restoration of normal sinus rhythm (NSR) in many patients, but it is not as successful if AF is present for more than 3 months preoperatively [16]. It is well known that during chronic AF the atria undergoes remodeling making perpetuation of AF more likely, in other words "AF begets AF" [17]. On the basis of our study, we cannot determine the time at which it is appropriate to perform an additional procedure for AF. We have generally limited use of radiofrequency ablation to patients with an AF duration of 6 months, but it may be more effective if used earlier.
Although there are other methods to perform atrial ablation, we have focused on radiofrequency energy due to its availability and ease of use. The ablation measurements we use are consistent with other investigators using similar devices and are devised based on in vitro work that predicts a lesion depth of approximately 4.4 mm with a range of 3 to 6 mm. The lesion grows with a half-time of 7.6 seconds with a steady state reached at 40 to 50 seconds [18]. We believe these values are appropriate to achieve transmural lesions but also avoid damage to surrounding structures. The structure of most concern is the circumflex artery, which could potentially be damaged during the lesion to the mitral valve annulus. Although this has never been a reported complication, we routinely give retrograde cardioplegia at some point during the lesion to protect this structure. Also, the circumflex artery is embedded in fat in the atrioventricular groove and unlike with cryo, fat is an excellent insulator of radiofrequency energy and thus it would be difficult to damage the artery with the ablation values we have chosen.
Perhaps the most exciting aspect of this study is the degree of success with only a left atrial procedure, providing an appealing option for the large amount of mitral valve patients with AF who currently receive no AF intervention. This is also supported by other investigators performing similar procedures [11–13]. The ability to stay within the left atrium using a simple technique such as radiofrequency can make this procedure more attractive to those without background or training in the Maze procedure. There are many theoretical reasons why an isolated left atrial procedure may be efficacious. First, it is known that focally induced AF frequently has an origin within the left atrium and predominantly the pulmonary veins [9]. Electrical isolation of the pulmonary veins, as was accomplished in all of our procedures, may help prevent initiation of AF. The posterior left atrium is also known to be the site with the shortest refractory periods and therefore, is more amenable to maintenance of a rapid rhythm such as AF. The ability for the left atrium to allow rotors of microreentry anchored near the pulmonary veins has been demonstrated in animals. Conduction then disperses from these rotors and takes different pathways through various anatomic barriers and variable musculature. The original frequency of the mother rotor undergoes transformation resulting in fibrillatory conduction rather than multiple wandering wavelets [10]. If the area where the rotors are anchored is isolated, then fibrillation may cease. This is somewhat consistent with our high incidence of perioperative AF. Postoperative AF largely results from dispersion of refractoriness. If there is greater dispersion then establishment of focal or microreentry circuits is more likely. In the case of a simplified procedure this will more commonly result in AF, as there are fewer surgical barriers to terminate the resulting pathways. This is the case in the Maze III where a near 35% perioperative AF rate occurs. However, as the inflammatory component of the operation resolves and the atria is restored to its normal refractory state, then AF is less likely to occur from other sites in the atrium. If the posterior left atrium is isolated, then the arrhythmia may not be able to persist. Although unproven in humans, this theory represents a likely and exciting explanation. The isolation of the left atrial appendage may also play a role in abolishing AF by either isolating foci or disrupting reentry. Because all patients had this aspect of the procedure performed, we cannot speculate on its effectiveness as an arrhythmia intervention, although our primary purpose of left atrial appendage exclusion was to decrease thromboembolic complications.
We frequently used amiodarone in this population and critics may question the relative benefits of amiodarone versus operation. We believe this is an appropriate intervention for several reasons. First, as the atrium does undergo remodeling during AF, promotion of any process that may permit recovery of this remodeling is advantageous. Also, the low dose and short duration of amiodarone we use should be safe. Finally, if AF recurs patients with amiodarone are better rate controlled. One group doing a similar procedure has shown that some patients having previously failed amiodarone become responsive to the drug after undergoing the procedure [19]. There are merits to a procedure that makes a patient more amenable to medical treatment.
There have been groups of researchers using a modified procedure who report an increased AFl incidence [20], although this group also included right-sided lesions. We have had 2 patients remain in AFl after only a left-sided procedure and none with a left- and right-sided procedure. We suspect that had a Maze III been performed, these patients would have converted to a normal rhythm as a flutter circuit is prevented with these lesions. Our larger concern is that patients with isolated pulmonary veins may develop an atypical left-sided flutter, which is difficult to treat. We routinely perform a lesion to the mitral valve annulus that should prevent this problem. If patients develop a typical right-sided flutter they may be appropriate candidates for a catheter-based right AFl ablation.
The future of this procedure will be in defining appropriate patient selection. It may be that a patient with rheumatic atrial pathology, 25 years of AF, and a 10-cm atrium may benefit from nothing other than a Maze III or similar modification. Whereas a more typical mitral valve patient will be better served by a simplified left atrial procedure. Long-term results still need to be characterized. We did not assess atrial contractile function, although other investigators have reported restoration of function [12, 13]. We do not suspect that our atrial function would be any worse than the greater than 90% contractility described by those with the Maze III where more incisions are used. Nonetheless, this will become an important component to characterize as more experience is accumulated.
In conclusion, we believe that surgical linear radiofrequency ablation is a safe and easy modality for creating effective lesions to be used in surgical management of AF. Although the limited lesion set benefits remain undefined, use of a left atrial procedure yields acceptable results in patients having concurrent cardiac operation. This limited simplified procedure can be made part of any surgeon’s armamentarium and may benefit patients that previously would have received no adjunctive therapy during concomitant open heart procedures.
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Discussion |
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We now have gone to using amiodarone therapy preoperatively in preparation for the procedure with a 5-day regimen and extending the therapy after operation with extremely improved results with the subsequent 5 patients that I have done since starting that operative procedure and appropriate medical therapy being in sinus rhythm after the procedure. We have altered all of the pathways. We had 3 patients who had difficult to control rates on maximal medical therapy, and after the ablation we have been able to maintain them either in sinus rhythm or control their rhythm quite nicely.
The atrial flutter is a problem. The electrophysiologists do not mind the patients being in flutter because this provides them with an opportunity to ablate the flutter in the catheter-based intervention, which they are quite successful at. And I think if you are not going to open up the right atrium for other reasons that this is a very appropriate way of managing this.
My one question to you will be, you have three different centers, eight different surgeons. What do you believe is the best operative procedure and lesion sets for this? We will never arrive at a consensus of opinion or a satisfactory operative procedure if we do not look at which patients benefit from which sets of lesions, and there is no information that you provided today as to which ones actually did better or was there even a difference? I know the numbers are small, but is there a difference?
DR WILLIAMS: Thank you for your comments and you raise several good points.
With regard to amiodarone, I think prophylaxis is a good idea, although I do not know of any data to support its use in this population. Our cardiologists have been reluctant to use amiodarone postoperatively so we have not broached preoperative use. We expect a high postoperative rate of atrial fibrillation and emphasize to centers to remain confident as the longer term results are much better. This is also true for the traditional Maze procedure where at least 35% of patients have postoperative atrial fibrillation despite excellent long-term success.
We did have 2 patients remain in atrial flutter without right-sided lesions. We did not pursue further management due to the cardiologist’s preference. I think a right-sided catheter-based ablation for flutter should be considered as part of the treatment plan in patients with only left-sided lesions and adds further validity to this approach. We are now doing a routine right-sided lesion to the tricuspid valve if the patient has a history of atrial flutter or if the planned procedure includes a tricuspid valve repair.
If you ask any electrophysiologist or surgeon working in this field they all have their own idea as to the ideal lesion set. There are several different left-sided lesion sets and most have comparable results, so I doubt we will ever know whether there is a best set in the absence of a well-planned randomized trial. I think the important components of any procedure are to isolate the pulmonary veins and the left atrial appendage. Other lesions will depend on surgeon bias as well as the approach as some lesions will be more difficult to accomplish minimally invasively.
DR JOHN W. HAMMON, JR (Winston-Salem, NC): I would like to congratulate you, Dr Williams, and your co-workers for being brave enough to get this research started. My questions relate to Dr Cox’s research on the coronary sinus. He showed early on in his animal experience that cryoablation of the coronary sinus in the region of the left atrium was very important and wondered your thoughts about the addition of cryoablation, and also on the type of atriotomy that was used in all these patients. Did they all have just a left atrial incision or were there any superior septal incisions, as that can markedly affect atrial conduction after the operation?
Thanks again for letting me see your manuscript.
DR WILLIAMS: Thank you. As you pointed out, Dr Cox believes the lesion on the coronary sinus is extremely important and he continues to advocate this even as he has made his procedure less invasive. We create a lesion from the pulmonary veins to the mitral valve annulus primarily, to prevent a left atrial flutter, although it may play a role in treating the atrial fibrillation. We think this lesion mimics what Dr Cox does with cryoablation. Some of our animal work demonstrates that our lesion penetrates to the coronary sinus, although it is not a circumferential lesion. There are other researchers who have avoided this lesion entirely and they still have similar results so I cannot say with certainty how important this lesion will be.
In terms of our approach, we routinely use a direct left atriotomy unless otherwise mandated. We only do superior septal approaches if we must operate on the tricuspid valve. The number of patients having this approach in this study is probably too small for me to speculate on any differences, although this should be analyzed as more experience is gained.
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|
|
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|
|
|
|
|
|
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|
|
|
|
|
|
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|
|
|
|
 |
|
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|
|
|
|
|
|
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|
|
|
|
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R. J. Damiano Jr Alternative energy sources for atrial ablation: judging the new technology Ann. Thorac. Surg., February 1, 2003; 75(2): 329 - 330. [Full Text] [PDF]
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A.M. Gillinov and P. M. McCarthy Atricure bipolar radiofrequency clamp for intraoperative ablation of atrial fibrillation Ann. Thorac. Surg., December 1, 2002; 74(6): 2165 - 2168. [Abstract] [Full Text] [PDF]
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A. M. Gillinov, E. H. Blackstone, and P. M. McCarthy Atrial fibrillation: current surgical options and their assessment Ann. Thorac. Surg., December 1, 2002; 74(6): 2210 - 2217. [Abstract] [Full Text] [PDF]
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M. R. Williams, M. Knaut, D. Berube, and M. C. Oz Application of microwave energy in cardiac tissue ablation: from in vitro analyses to clinical use Ann. Thorac. Surg., November 1, 2002; 74(5): 1500 - 1505. [Abstract] [Full Text] [PDF]
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J. S. Raman, S. Ishikawa, and J. M. Power Epicardial radiofrequency ablation of both atria in the treatment of atrial fibrillation: experience in patients Ann. Thorac. Surg., November 1, 2002; 74(5): 1506 - 1509. [Abstract] [Full Text] [PDF]
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E. Manasse, P. Pugliese, A. Barbone, and R. Gallotti Left atrial epicardial ablation associated to a Bentall procedure Eur. J. Cardiothorac. Surg., October 1, 2002; 22(4): 633 - 635. [Abstract] [Full Text] [PDF]
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S. Benussi, S. Nascimbene, E. Agricola, G. Calori, S. Calvi, A. Caldarola, M. Oppizzi, V. Casati, C. Pappone, and O. Alfieri Surgical ablation of atrial fibrillation using the epicardial radiofrequency approach: mid-term results and risk analysis Ann. Thorac. Surg., October 1, 2002; 74(4): 1050 - 1057. [Abstract] [Full Text] [PDF]
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M. Guden, B. Akpinar, I. Sanisoglu, E. Sagbas, and O. Bayindir Intraoperative saline-irrigated radiofrequency modified Maze procedure for atrial fibrillation Ann. Thorac. Surg., October 1, 2002; 74(4): S1301 - 1306. [Abstract] [Full Text] [PDF]
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H. Oral, B. P. Knight, M. Ozaydin, A. Chugh, S. W.K. Lai, C. Scharf, S. Hassan, R. Greenstein, J. D. Han, F. Pelosi Jr, et al. Segmental Ostial Ablation to Isolate the Pulmonary Veins During Atrial Fibrillation: Feasibility and Mechanistic Insights Circulation, September 3, 2002; 106(10): 1256 - 1262. [Abstract] [Full Text] [PDF]
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G. S. Kopf, D. M. Mello, K. M. Kenney, J. Moltedo, N. R. Rollinson, and C. S. Snyder Intraoperative radiofrequency ablation of the atrium: effectiveness for treatment of supraventricular tachycardia in congenital heart surgery Ann. Thorac. Surg., September 1, 2002; 74(3): 797 - 804. [Abstract] [Full Text] [PDF]
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S. Zhou, C.-M. Chang, T.-J. Wu, Y. Miyauchi, Y. Okuyama, A. M. Park, A. Hamabe, C. Omichi, H. Hayashi, L. A. Brodsky, et al. Nonreentrant focal activations in pulmonary veins in canine model of sustained atrial fibrillation Am J Physiol Heart Circ Physiol, September 1, 2002; 283(3): H1244 - H1252. [Abstract] [Full Text] [PDF]
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F. Gaita and R. Riccardi Lone atrial fibrillation ablation: Transcatheter or minimally invasive surgical approaches? J. Am. Coll. Cardiol., August 7, 2002; 40(3): 481 - 483. [Full Text] [PDF]
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P.-S. Chen, T.-J. Wu, C. Hwang, S. Zhou, Y. Okuyama, A. Hamabe, Y. Miyauchi, C.-M. Chang, L. S. Chen, M. C. Fishbein, et al. Thoracic veins and the mechanisms of non-paroxysmal atrial fibrillation Cardiovasc Res, May 1, 2002; 54(2): 295 - 301. [Abstract] [Full Text] [PDF]
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