Interactive Cardiovascular and Thoracic Surgery 1:55-57(2002)
© 2002 European Association of Cardio-Thoracic Surgery
Off-pump epicardial compartmentalization for ablation of atrial fibrillation
Patrick Ruchata,*,
Jürg Schlaepferb and
Ludwig K. von Segessera
a Department of Cardiovascular Surgery, University Hospital, rue du Bugnon 46, Lausanne, Switzerland
b Department of Cardiology, University Hospital, Lausanne, Switzerland
* Corresponding author. Tel.: +41-21-314-2280; fax: +41-21-314-2278
patrick.ruchat{at}chuv.hospvd.ch
Received March 28, 2002;
received in revised form July 16, 2002;
accepted July 19, 2002
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Abstract
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The Cox–Maze-III procedure still remains the gold standard in surgical treatment of atrial fibrillation.The major hazard of atrial fibrillation is thromboembolic event to the brain. Left atrial appendage (LAA) represents the source of thrombus and subsequent embolism although LAA obliteration is a key point to prevent thrombogenesis. We describe a simplified off-pump compartmentalization procedure using epicardial radiofrequency ablation of the left atrium and LAA stapling on the beating heart without cardiopulmonary bypass.
Key Words: Atrial fibrillation; Beating heart surgery; Radiofrequency ablation; Arrhythmia surgery; Stapling technique
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1. Introduction
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The excellent results of the maze-III operation developed by Cox showed that a surgical cure of atrial fibrillation (AF) was possible. This procedure involves creating multiple barrier-incisions within the atria to interrupt the macro-reentrant electrical circuits perpetuating the AF [1]. Epicardial radiofrequency (RF) ablation of the atrial tissue performed during mitral valve surgery has been recently shown to be effective in terminating chronic AF. The left atrial appendage (LAA) is commonly the origin of thrombus and subsequent embolism. Its obliteration during mitral valve surgery in AF patients has been recommended for some time. In an effort to reduce the invasiveness of the antiarrhythmic procedure, we have used the highly effective radiofrequency (RF) energy to create atrial wall lesions through the epicardium without cardiopulmonary bypass.
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2. Technique
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We start the operation by the arrhythmia procedure. The pericardial fold between the superior vena cava and the right superior pulmonary vein was fully opened to give access to the roof of the left atrium. The pericardial reflection line between the inferior vena cava and the right inferior pulmonary vein was incised to give access to the floor of the left atrium along the inferior pulmonary veins. After sharp epicardial dissection of the Waterston interatrial groove, RF catheter Thermaline ProbeTM, (Boston Scientific Corporation, San José, CA, USA) was moulded and applied in front of right pulmonary veins for a application time of 4min at 70°C. A second catheter application was applied joining the right superior pulmonary vein to the superior edge of the left atrial appendage, passing in front of the left upper pulmonary vein for another 4min. The same time of application was performed on the left atrial floor, along and very close to the inferior pulmonary veins reaching the inferior edge of the left atrial appendage (Fig. 1).
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Fig. 1 Epicardial RF application pattern on the right aspect of the left atrium. Dashed line 1, in front of right pulmonary veins; dashed line 2, on the roof of left atrium; dashed line 3, between inferior right pulmonary vein and LAA inferior edge.
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Routine peroperative transesophageal echocardiography ruled out any LAA thrombus. In Trendelenburg position, the heart is progressively lifted to the right and verticalized after having placed a deep pericardial suture. The lateral aspect of the left atrium is gently exposed to reach the left atrial appendage. Atrioventricular sulcus was thoroughly dissected to preserve the circonflex artery and the small cardiac vein. A RF ablation line was completed from the appendage towards the mitral annulus with special attention to avoid injury to the atrioventricular vessels. The disposable surgical stapler, 60–3.5mm ENDO GIA II (AutoSutureTM: United States Surgical Corporation, 06856 Norwalk CT, USA) was applied to the base of the left atrial appendage while its tip was gently drawn by a forceps. Firing the endoGIA-stapler obliterated its orifice and amputated the complete body of the LAA in one single shot (Fig. 2).
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Fig. 2 Epicardial RF ablation lines on left aspect of the left atrium. Dashed line 4: from LAA to the mitral annulus in the atrioventricular sulcus followed by excision of LAA with endo-GIA stapler.
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2.1. Personal experience
From August 2001, epicardial compartmentalization was performed in two patients to ablate symptomatic, drug-resistant chronic AF concomitantly to other cardiac surgical procedure. All the ablation lines were performed on the beating heart before canulation. A 54-year-old man was operated on for an ostium secundum ASD closure and chronic AF for 6 months. After sinus rhythm restoration, he was treated by flecaïnid (DCI, Dénomination Commune Internationale) for 6 weeks because of amiodarone untolerance. A 76-year-old woman had an aortic valve replacement because of severe aortic stenosis and chronic AF for 9 months. The lady was treated with propafenone (DCI) for 3 months because of history of hyperthyroidism. Both had sinus rhythm restored before the main surgical procedure and were anticoagulated for 6 months postoperatively with acenocoumarol (DCI). We had no perioperative complication. At 6-month follow-up, the first patient had a percutaneous ablation of the cosio' isthmus for a recurrent typical atrial flutter. The woman was in sinus rhythm without antiarrythmic medication.
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3. Comment
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Alternative surgical procedures to the Cox–Maze operation have been proposed to ablate either lone or secondary AF. We had documented the effectiveness of epicardial RF ablation of acute AF in a sheep model [2]. Since then, Benussi et al. reported partial epicardial ablation, starting on the beating heart but completing the procedure endocardially on standard cardiopulmonary bypass (CPB) [3]. Melo was the first to describe epicardial RF isolation of the pulmonary veins without CPB [4] and Mazzitelli to describe the first complete beating heart maze procedure [5]. In order to avoid the risk of ablation-related thromboembolism and unnecessary left atriotomy we choose to adopt an epicardial limited application of RF. Our initial work confirms the feasability of epicardial AF ablation on the beating heart completely off-pump. None of the patients presented any bleeding or complication due to external LAA resection or RF application. However, treatment of lone atrial fibrillation is exclusively performed by percutaneous catheter ablation, combining beating heart surgery and epicardial RF or microwaves ablation could further expand the indications for surgical therapy of lone AF.
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Appendix A
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ICVTS on-line discussion
Author: Dr. Kwaku Ayisi, Cardio-vascular Surgery, University Hospital Hamburg, Martinistr. 52, Hamburg, Germany
Date: 11-Aug-2002 19:35
Message: The authors have described a very simple and interesting variation of the Cox-maze technique in the surgical treatment of atrial fibrillation. The ablation-pathways described are easily accessible; the method less time consuming and complications seem minimal, especially the risk of injury to the oesophagus seems practically non-existent. The technique would certainly encourage surgeons to do such procedures more.
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Acknowledgements
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The figures have been prepared with the technical assistance of Mr Willy Guyot, CEMCAV, CHUV, Lausanne.
PII: S1569929302000130
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References
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- Cox JL, Jaquiss RD, Schuessler RB, Boineau JP. Modification of the maze procedure for atrial flutter and atrial fibrillation. J Thorac Cardiovasc Surg. 1995;110:485–495[Abstract/Free Full Text]
- Ruchat P, Schlaepfer J, Fromer M, Gardaz JP, Genton CY, Von Segesser LK. Atrial fibrillation inhibition by subepicardial radiofrequency ablation in a sheep model. Abstract of the 12th annual meeting of the EACTS, 1998. p. 434.
- Benussi S, Pappone C, Nascimbene S, Oreto G, Caldarola A, Stefano PL, Casati V, Alfieri O. A simple way to treat chronic atrial fibrillation during mitral valve surgery: the epicardial radiofrequency approach. Eur J Cardiothorac Surg. 2000;17:524–529[Abstract/Free Full Text]
- Melo J, Adragao P, Neves J, Ferreira M, Timoteo A, Santiago T, Ribeiras R, Canada M. Endocardial and epicardial radiofrequency ablation in the treatment of atrial fibrillation with a new intra-operative device. Eur J Cardiothorac Surg. 2000;18:182–186[Abstract/Free Full Text]
- Mazzitelli D, Park CH, Park KY, Benetti FJ, Lange R. Epicardial ablation on the beating heart without cardiopulmonary bypass. Ann Thorac Surg. 2002;73:320–321[Abstract/Free Full Text]
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Abstract
1. Introduction