| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 2002;74:S1307-S1311
© 2002 The Society of Thoracic Surgeons
a Department of Cardiothoracic Surgery, University Hospital Maastricht, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands
b Department of Cardiology, University Hospital Maastricht, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands
* Address reprint requests to Dr Maessen, CARIM, Department of Cardiothoracic Surgery, University Hospital Maastricht, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands
e-mail: jma{at}scpc.azm.nl
Presented at the Eighth Annual Cardiothoracic Techniques and Technologies Meeting 2002, Miami Beach, FL, Jan 23–26, 2002.
 |
Abstract |
|---|
 Top Abstract IntroductionPatients and methodsAcknowledgmentsReferences |
|---|
METHODS: From June 2001 until December 2001, a total of 24 patients underwent beating-heart epicardial ablation for AF. With a microwave antenna, the left and right pulmonary veins were isolated and connected to each other followed by amputation of the left atrial appendage. Subsequently, patients underwent either off-pump coronary artery bypass graft or valve surgery on pump. The mean age of the patients was 67.4 ± 6 years. Three patients experienced paroxysmal atrial fibrillation and all others chronic AF. Mean left atrial diameter was 5.4 ± 0.6 cm, and mean ablation time was 13 min.
RESULTS: All procedures but one were completed successfully on the beating heart. All patients were in sinus rhythm after the procedure. A total of 15 patients experienced periods with postoperative AF during hospital stay; 9 of these patients were discharged with AF. All patients received either sotalol or amiodarone. At latest follow-up (3 to 9 months), 20 of 23 patients were in sinus rhythm.
CONCLUSIONS: With microwave ablation, electrical isolation of the pulmonary veins can be achieved epicardially without cardiopulmonary bypass support.
|
Introduction |
|---|
|
TopAbstractIntroductionPatients and methodsAcknowledgmentsReferences |
|---|
As surgical ablation therapy is additional to primary surgery and thus prolongs cardiopulmonary bypass and crossclamp time, catheter technology developments aim at obtaining reliable transmural ablation lesions in the shortest time possible [5]. In addition to cryoablation and radio-frequency, microwave energy has become available, as well as catheters that create longer lesion line within one application [6]. An alternative approach to save time is offered by performing the ablation procedure before concomitant surgery on a beating heart and off pump. This approach also allows application of the ablation procedure in off-pump coronary artery bypass graft (CABG) surgery. An additional advantage might be electrophysiological evaluation of the conduction block created by ablation in a normothermic working heart during the procedure itself.
To evaluate the feasibility of such an approach, the following questions were addressed: (1) Does the beating heart allow anatomical preparation to achieve epicardial access to the pulmonary veins with a currently available catheter? (2) Is it possible to obtain epicardially a conduction block around the pulmonary veins in a reproducible way? (3) What is the value of immediate testing of the conduction block during the procedure with simple electrophysiological means? These questions were addressed in a series of 24 consecutive patients with atrial fibrillation who were scheduled for valvular or coronary surgery.
|
Patients and methods |
|---|
|
TopAbstractIntroductionPatients and methodsAcknowledgmentsReferences |
|---|
Standard anesthetic (lorazepam, fentanyl citrate, sufentanil citrate, alfentanil hydrochloride, midazolam hydrochloride, pancuronium bromide) and monitoring techniques (electrocardiography, central venous/pulmonary and arterial pressure monitoring, urinary output, rectal and skin temperature monitoring) were used in all patients. In the case of off-pump coronary surgery, an Axius Xpose Device (Guidant Corporation, Cupertino, CA) allowed stabilization of the heart and exposure of the coronary arteries. A cell-saving device (CATS, Fresenius, Germany) was used from the start of surgery to salvage and to autotransfuse all blood lost during the procedure.
Temporary epicardial pacing wires were positioned at the transition of the right pulmonary veins to the left atrium or at the roof of the left atrium as reached at from within the transverse sinus to assure positioning within the area to be isolated. Additional pacing wires were placed close to the interventricular septum and behind the right atrial appendage. Pacing wires were used for evaluating the conduction block as well as for rate control in the postoperative period. Before starting ablation therapy, epicardial electrical cardioversion was attempted to bring the patient into sinus rhythm so as to facilitate evaluation of the ablation effect. If not successful, cardioversion was repeated up to three times.
The off-pump beating-heart ablation procedure was performed according to the following steps: (1) epicardial electrical conversion to sinus rhythm; (2) positioning of temporary pacing wires; (3) opening of the oblique sinus and the transverse sinus (see Fig 1); (4) opening of the pericardial reflection between the superior right pulmonary vein and the superior vena cava; (5) opening of the pericardial reflection between the inferior right pulmonary vein and the inferior vena cava into the oblique sinus; (6) dissection of the intraatrial groove and removal of fat tissue; (7) removal of fat tissue at the roof of the left atrium in the transverse sinus; (8) resection of the left atrial appendage; (9) positioning of a sling through the transverse sinus; (10) positioning of a second sling from the inferior pulmonary vein through the oblique sinus into the transverse sinus; (11) surgical ablation according to the line set in Figure 2; and (12) verification of the conduction block. The ablation was performed using a microwave energy ablation catheter (Afix Inc, Fremont, CA) with a 4-cm flexible antenna and a malleable shaft.
|
|
Results
Consecutive enrollment into the study of patients in atrial fibrillation resulted in the inclusion of 24 patients, of which 7 patients had coronary surgery (1 on pump, 6 off pump), 6 aortic valve replacement, 6 mitral valve replacement or repair, 1 combined aortic valvular replacement and CABG, 1 combined aortic and mitral valve replacement, and 3 combined mitral valve replacement and CABG. The mean age of the patients was 67.4 ± 6 years. Of 24 patients, 3 experienced paroxysmal atrial fibrillation. A total of 21 patients were in chronic atrial fibrillation, with a mean duration of fibrillation before surgery of 4.4 years (range 1 to 14 years). Left atrial enlargement (maximum 64 mm) was present in all but 2 cases. All patients had been medically treated for atrial fibrillation previous to surgery. Three patients underwent frequent cardioversion. In 1 patient, percutaneous RF ablation for atrial flutter was unsuccessful, with subsequent development of chronic atrial fibrillation.
The mean number of applications of the ablation catheter was 8.5 (range 6 to 12 applications), with a mean ablation time of 13 minutes. Positioning of the heart dissection of the pericardial reflections and resection of the left atrial appendage required another 15 to 30 minutes (mean 21 minutes).
In 17 of 24 patients, epicardial electrical conversion into sinus rhythm at the beginning of the procedure was successful. Thus, the conduction block resulting from the ablation could be verified by pacing using the left atrial pacing wires (Fig 3). A total of 12 patients lost capture after isolation of the pulmonary veins. In 4 patients, loss of capture could eventually be obtained with additional ablation applications in the area of the left atrial roof from within the transverse sinus. In 1 patient with initial failure, macroscopically no gap in the continuity of the ablation lines could be detected. Since it concerned a mitral valve repair case, the ablation procedure was repeated endocardially on pump. In patients with unsuccessful cardioversion after three attempts, the conduction block was considered to be effective if the pace pulse initiated from the left atrial pacing wires was significantly delayed as observed with the right atrial pacing wires. Three of these patients, however, spontaneously adopted sinus rhythm upon completion of the pulmonary veins isolation. The remaining patients appeared to be in sinus rhythm at the end of the concomitant surgical procedure. In 1 patient with aortic valve stenosis low cardiac output after induction of anesthesia necessitated cardiopulmonary bypass. In this case, the ablation procedure was continued on the beating heart with cardiopulmonary bypass support. All patients were in sinus rhythm at the end of surgery. The left atrial appendage was resected after creating a suture line with Ticron 2-0 (Sherwood–Davis & Geck, St. Louis, MO) at the base of the appendage. In half of the patients, resection was obtained with an Endogia (USSC, Norwalk, CT) stapling device.
|
|
|
Endocardial surgical catheter ablation has been shown to offer a successful alternative to the Cox-Maze procedure in the treatment of atrial fibrillation [7]. Introduction of this technique has rapidly increased the number of patients treated since it has been generally offered to patients who were primarily scheduled for surgery for concomitant cardiac disease. Technically less demanding, the technique has been adopted by many surgeons in a short time The fact that its success percentage is less than the reported 90% to 100% with the surgical Maze procedure has therefore been accepted. The present study shows that with a completely epicardial approach, a success percentage similar to that of the endocardial procedure can be obtained. Follow-up time in this study is limited; however, in previous ablation studies, the efficacy further improved between 6 months and 1 year of follow-up [8].
Although less time consuming than the surgical procedures, the endocardial ablation approach still prolongs crossclamp time and does not allow electrophysiological control of the conduction block until release of the aortic clamp and weaning from CPB.
If reablation is needed because of incomplete results, one has to face reinstitution of cardiopulmonary bypass and renewed crossclamping. In the present study, online evaluation of the conduction block led to additional ablation therapy in 25% of patients. A better understanding of the development in time of a conduction block after ablation and further simplification of the electrophysiological methods may improve the value of online testing in the near future [9].
Until now, the rapidly growing population of patients scheduled for off-pump coronary artery bypass surgery has been withheld surgical ablation of atrial fibrillation or not the procedure was converted to on-pump to allow ablation. In the present study, we showed that epicardial off-pump ablation can be combined to off-pump coronary artery bypass surgery without additional complications or increasing numbers of conversions to on pump.
Study limitations
The objective of this study was to evaluate the feasibility of an epicardial off-pump ablation approach. Its main focus, therefore, was the surgical aspects of this technique. Whether such a procedure and the ablation line set used is the best approach for either valvular disease or coronary insufficiency patients has yet to be established.
With some radiofrequency catheters, ablation damage to the esophagus has been described. With the design of the microwave catheter, such damage is unlikely to occur because of the rapid temperature decline beyond the distance of 5 mm from the device. Furthermore, the unidirectional energy release of the catheter prevents collateral damage. In the epicardial beating heart approach, this is important, as it allows ablation at the dorsal part of the heart without additional protective measurements since the energy is released only in a ventral direction.
The need for removal of fat tissue may be disputed, as the presence of fat tissue may not affect the lesion depth. The authors believe, however, that in the areas in which the fat tissue is present, the atrial wall may be thickest. Furthermore, boiling the fat tissue during ablation makes the antenna sticky, which may hamper subsequent ablations.
The proposed procedure does not demand tilting of the heart with resulting hemodynamic fluctuations. Bringing the patient into sinus rhythm and subsequent atrial pacing at a rate of 90 beats per minute remarkably stabilizes and improes hemodynamic conditions.
|
Acknowledgments |
|---|
|
TopAbstractIntroductionPatients and methodsAcknowledgmentsReferences |
|---|
|
References |
|---|
|
TopAbstractIntroductionPatients and methodsAcknowledgmentsReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  W. Wisser, G. Seebacher, T. Fleck, C. Aigner, C. Khazen, G. Stix, D. Hutschala, and E. Wolner Permanent Chronic Atrial Fibrillation: Is Pulmonary Vein Isolation Alone Enough? Ann. Thorac. Surg., October 1, 2007; 84(4): 1151 - 1157. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Doty, D. B. Doty, K. W. Jones, J. H. Flores, M. Mensah, B. B. Reid, S. E. Clayson, G. Snow, E. Righter, and R. C. Millar Comparison of standard Maze III and radiofrequency Maze operations for treatment of atrial fibrillation J. Thorac. Cardiovasc. Surg., April 1, 2007; 133(4): 1037 - 1044. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. J. Melby, A. Zierer, S. P. Kaiser, R. B. Schuessler, and R. J. Damiano Jr Epicardial microwave ablation on the beating heart for atrial fibrillation: The dependency of lesion depth on cardiac output. J. Thorac. Cardiovasc. Surg., August 1, 2006; 132(2): 355 - 360. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Jahangiri, G. Weir, K. Mandal, I. Savelieva, and J. Camm Current strategies in the management of atrial fibrillation. Ann. Thorac. Surg., July 1, 2006; 82(1): 357 - 364. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Q. Melo Surgery for atrial fibrillation: Are we heading in the right direction? J. Thorac. Cardiovasc. Surg., May 1, 2006; 131(5): 949 - 951. [Full Text] [PDF]
|
|
|
|
|
|
S. D. Barnett and N. Ad Surgical ablation as treatment for the elimination of atrial fibrillation: A meta-analysis J. Thorac. Cardiovasc. Surg., May 1, 2006; 131(5): 1029 - 1035. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Gaynor, G. D. Byrd, M. D. Diodato, Y. Ishii, A. M. Lee, S. M. Prasad, J. Gopal, R. B. Schuessler, and R. J. Damiano Jr Microwave Ablation for Atrial Fibrillation: Dose-Response Curves in the Cardioplegia-Arrested and Beating Heart Ann. Thorac. Surg., January 1, 2006; 81(1): 72 - 76. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Benussi and O. Alfieri Concomitant ablation of atrial fibrillation during mitral surgery MMCTS, November 29, 2005; 2005(1129): 1081. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. E. Accord, R.-J. van Suylen, T. J. van Brakel, and J. G. Maessen Post-Mortem Histologic Evaluation of Microwave Lesions After Epicardial Pulmonary Vein Isolation for Atrial Fibrillation Ann. Thorac. Surg., September 1, 2005; 80(3): 881 - 887. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Ninet, X. Roques, R. Seitelberger, C. Deville, J. L. Pomar, J. Robin, O. Jegaden, F. Wellens, E. Wolner, C. Vedrinne, et al. Surgical ablation of atrial fibrillation with off-pump, epicardial, high-intensity focused ultrasound: Results of a multicenter trial J. Thorac. Cardiovasc. Surg., September 1, 2005; 130(3): 803 - 803. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. S Kabbani, G. Murad, H. Jamil, A. Sabbagh, and K. Hamzeh Ablation of Atrial Fibrillation Using Microwave Energy - Early Experience Asian Cardiovasc Thorac Ann, September 1, 2005; 13(3): 247 - 250. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. J. van Brakel, G. Bolotin, L. W. Nifong, A. L.A.J. Dekker, M. A. Allessie, W. R. Chitwood Jr, and J. G. Maessen Robot-assisted epicardial ablation of the pulmonary veins: is a completed isolation necessary? Eur. Heart J., July 1, 2005; 26(13): 1321 - 1326. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. C. Reade, J. O. Johnson, G. Bolotin, W. L. Freund Jr, N. L. Jenkins, C. E. Bower, S. Masroor, A. P. Kypson, L. W. Nifong, and W. R. Chitwood Jr Combining Robotic Mitral Valve Repair and Microwave Atrial Fibrillation Ablation: Techniques and Initial Results Ann. Thorac. Surg., February 1, 2005; 79(2): 480 - 484. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Bolotin, A. P. Kypson, L. W. Nifong, and W. R. Chitwood Jr Robotically-Assisted Left Atrial Fibrillation Ablation and Mitral Valve Repair Through a Right Mini-Thoracotomy Ann. Thorac. Surg., October 1, 2004; 78(4): e63 - e64. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. J. van Brakel, G. Bolotin, K. J. Salleng, L. W. Nifong, M. A. Allessie, W. R. Chitwood Jr, and J. G. Maessen Evaluation of Epicardial Microwave Ablation Lesions: Histology Versus Electrophysiology Ann. Thorac. Surg., October 1, 2004; 78(4): 1397 - 1402. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Gerosa, R. Bianco, G. Buja, and F. di Marco Totally endoscopic robotic-guided pulmonary veins ablation: an alternative method for the treatment of atrial fibrillation Eur. J. Cardiothorac. Surg., August 1, 2004; 26(2): 450 - 452. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Athanasiou, P. Kumar, S. Al-Ruzzeh, O. Aziz, A. Charitou, J. Hart, B. Glenville, and R. Casula Expanded use of suction and stabilization devices in cardiothoracic surgery Ann. Thorac. Surg., October 1, 2003; 76(4): 1126 - 1130. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. T Sie, W. P Beukema, A. Elvan, and A. R Ramdat Misier New strategies in the surgical treatment of atrial fibrillation Cardiovasc Res, June 1, 2003; 58(3): 501 - 509. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Malik JournalScan Heart, January 1, 2003; 89(1): 119 - 120. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
