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Combined mitral valve surgery and the Maze III procedure
Combined Mitral Valve Surgery and the Maze III Procedure Niv Ad and James L. Cox Atrial fibrillation is present in approximately 50% of patients undergoing surgery for mitral valve disease. In the past, surgeons were forced to ignore atrial fibrillation when performing open-heart surgery for other indications simply because there was no proper surgical solution and little awareness of the medical consequences of atrial fibrillation. The Maze procedure was introduced in 1987 and when properly performed, its results when combined with mitral valve surgery have been excellent, with no increase in perioperative morbidity and mortality and with documented long-term advantages over simply leaving patients with atrial fibrillation. In this study we evaluated our recent results in 53 patients undergoing mitral valve surgery in combination with the Maze III procedure. Our results indicate that the Maze III procedure is just as safe and effective in controlling atrial fibrillation associated with mitral valve disease as it is in controlling atrial fibrillation not associated with mitral valve disease. Copyright 2002, Elsevier Science (USA). All rights reserved.
I
n our initial clinical experience with the Maze procedure, we purposely avoided operating on patients who might need concomitant valve surgery. We did this because we felt that the complexity of the Maze procedure would cause increased operative time, and thus the combined procedure would be unsafe.1-4 Therefore, only after accumulating substantial experience with the Maze procedure alone did we apply it in combination with valve surgery. In recent years, we simplified the surgical procedure by abandoning the classical “cut-and-sew” technique and adopting a cryosurgical technique that we had introduced for the minimally invasive Maze procedure.5 With this new approach, we apply the same atrial lesions as in the cutand-sew technique, but use cryothermia to create the lesions. In addition, to avoid isolating so much of the normal left atrium between the right and left pulmonary veins, we no longer encircle all four pulmonary veins together, but rather encircle the right pulmonary veins as a unit and the left pulmonary veins as a unit. The efficacy of this modification is not affected by the work of From the Hadassah University Hospital, Jerusalem, Israel and the World Heart Foundation, Washington, DC. Address reprint requests to Niv Ad, MD, Thoracic and Cardiovascular Surgery, Hadassah University Hospital, Jerusalem 91120, Israel. Copyright 2002, Elsevier Science (USA). All rights reserved. 1043-0679/02/1403-0000$35.00/0 doi:10.1053/stcs.2002.34395
206
Hassiguerre et al6 on the origin of premature beats within the pulmonary veins that initiate paroxysmal atrial fibrillation. The current report of our results includes only those patients who underwent the Maze III procedure with or without its latest modifications when combined with mitral valve surgery.
Methods Patient Data Between July 1, 1997 and September 1, 2001, 53 patients underwent the Maze III procedure (hereafter referred to simply as the “Maze procedure”) combined with mitral valve surgery alone (44 patients) or combined with mitral valve surgery and tricuspid valve repair (9 patients). Four patients underwent the procedure as a “redo” operation. The average duration of the arrhythmia before it was treated surgically was 4.7 years (range, 0.5 to 20 years) for the paroxysmal atrial fibrillation group and 3.4 years (range, 6 months to 40 years) for the chronic atrial fibrillation group (Table 1). All of the patients had failed medical therapy before surgery; 44% of the patients had failed amiodarone therapy as well. The major indications for applying the Maze procedure in combination with mitral valve surgery were arrhythmia intolerance in 75% (40 of 53), drug intolerance in 15% (8 of 53), and previous thromboembolic event in 10% (5 of 53).
Seminars in Thoracic and Cardiovascular Surgery, Vol 14, No 3 ( July), 2002: pp 206-209
Mitral Valve Surgery and Maze III Procedure
Table 1. Patient Demographics Parameter
Maze Plus Mitral Valve Surgery
Average age (years) 59 ⫾ 13.3 (17 to 76 years) Female gender 45% Paroxysmal atrial fibrillation 41% Duration (years) 4.7 (6 months to 20 years) Chronic atrial fibrillation 59% Duration (years) 3.4 (0.5 year to 40 years) Previous surgery 7.5% (4 patients) Previous stroke/TIA 10% (5 patients) Rheumatic heart disease 15% (8 patients)
Fifty-three patients underwent 62 valve operations, including 37 mitral valve repairs, 39 mitral valve replacements, and 9 tricuspid valve repairs (Table 2). In 16 patients the procedure was done using cryothermal energy to perform the atrial lesions, and in 17 patients the procedure was done as a minimally invasive operation via a small right anterior thoracotomy.
Operative Technique The patient was placed in the standard supine position for the median sternotomy approach or in the right anterolateral position for the minimally invasive approach. The operation was carried out using cardiopulmonary bypass via separate caval cannulation with aortic (median sternotomy) or femoral artery (minimally invasive) cannulation. The patient was systemically cooled to 28°C, and the heart was initially arrested using antegrade warm-blood cardioplegia, followed by antegrade and retrograde cold-blood cardioplegia thereafter. In the beginning of the series, the Maze procedure was performed using the cut and sew technique.2 Later in the series, it was done using cryothermal energy7 for placing the atrial lesions.
Follow-Up The patient was returned to the care of his or her referring physician after hospital discharge. Because most of our patients were from long distances away, we followed them primarily by telephone for the first several weeks and then had them return for a formal evaluation 6 months after surgery (see below)
207
Anticoagulant Regimen Patients undergoing combined mitral valve surgery and the Maze procedure received anticoagulation therapy with sodium warfarin according to the type of mitral valve surgery that they underwent. Patients who had mitral valve repair or mitral valve replacement with a biologic valve were anticoagulated for 3 months. Those who had mitral valve replacement with a mechanical valve were anticoagulated for life. Six-Month Postoperative Evaluation By 6 months postoperatively, the patients had been off all antiarrhythmic medications for 3 months and had recuperated sufficiently from surgery to allow evaluation. At that time, they all underwent the following battery of tests: standard electrocardiography, 24-hour Holter monitoring, exercise stress test, and transthoracic echocardiography. The objectives of these tests were to document that (1) the patient is in a normal sinus rhythm or an atrioventricular (AV)paced rhythm with restoration of normal AV activation, (2) there are no persistent arrhythmias, (3) the chronotropic response of the sinus node (or pacemaker) is normal, and (4) both the right and left atria are contracting (documented A waves). If transthoracic echocardiography failed to detect the latter, especially function in the left atrium, then an immediate transesophageal echocardiography was performed. Because our previous experience had shown a high incidence of false-negative results using transthoracic echocardiography, we used this test as a screening device but not as the final arbiter of whether or not left atrial function was present after the Maze procedure.
Table 2. Types of Concomitant Surgery Combined With the Maze Procedure Surgical Procedure Mitral valve repair combined with the Maze procedure Redo mitral valve repair Combined with tricuspid valve repair Mitral valve replacement combined with the Maze procedure Redo mitral valve replacement Combined with tricuspid valve repair
Number of Patients 28 1 5 25 3 4
Ad and Cox
208
Table 4. Univariate Analysis for Predictors of Perioperative Death
Results Perioperative Results The mortality rate for patients undergoing combined mitral valve surgery and the Maze procedure was 3.8 % (2 of 53 patients) (Table 3). The one male and one female who died were both older than 70, and neither underwent a “redo” procedure. One had a cryosurgical Maze procedure combined with mitral valve replacement, and the other had a minimally invasive mitral valve repair plus the Maze procedure. Multivariate analysis of different parameters revealed no significant predictors for operative mortality, although this group of patients is relatively small (Table 4). Of particular interest is the incidence of perioperative atrial arrhythmias of 34% (18 patients). No perioperative strokes or transient ischemic attacks (TIAs) occurred in the group undergoing the Maze procedure and concomitant valve surgery. Fluid retention has been a significant problem in the past and occurred in 10% of our patients, but is no longer a problem because of the aggressive diuretic protocol that we now follow in all of our patients.8 A total of 10 patients required a new permanent pacemaker after the surgical procedure, 2 due to complete AV block and 8 (16%) due to preexisting sinus node dysfunction.
Parameter
P Value
Year of surgery Gender Age Duration of atrial fibrillation Type of atrial fibrillation Previous TIA/stroke Preoperative amiodarone Preoperative beta-blockers Preoperative diuretics Preoperative congestive heart failure Preoperative left ventricular ejection fraction Preoperative renal failure Preoperative chronic obstructive pulmonary disease Preoperative hypertension Preoperative diabetes mellitus Redo procedure Minimally invasive procedure Cryosurgical procedure
0.4 0.4 0.6 0.1 0.9 0.4 0.3 0.4 0.8 0.7 0.7 0.8 0.4 0.2 0.1 0.85 0.35 0.25
after the procedure; the arrhythmia was controlled by medication in only one of these patients, meaning that 98% of the patients had their arrhythmia abolished. No late strokes or TIAs occurred during the follow-up period.
Discussion
Late Results The mean follow-up time for this group is 2.8 ⫾0.9 years (range, 4 months to 4 years and 4 months). There was one late death (2%) not related to the Maze procedure. This was a 58-yearold male who underwent valve replacement with a mechanical valve and developed prosthetic valve endocarditis 7 weeks after surgery. Two patients (4%) had documented atrial arrhythmia
Table 3. Early Results for Combined Mitral Valve Surgery and the Maze III Procedure Complication
Percentage
Atrial arrhythmia Perioperative bleeding Stroke TIA New pacemaker (total) Sinus node dysfunction Operative death
34 6.5 0 0 10 8 3.8
Approximately 40% of patients who undergo the Maze procedure for atrial fibrillation experience typical postoperative atrial fibrillation in the immediate postoperative period for reasons outlined earlier. We consider the first 3 months after surgery to be the period needed for the atrium to heal from the surgery and for the local refractory periods in the atrium, which determine the vulnerability to atrial fibrillation, to return to their baseline preoperative values.4 We have learned that the long-term results of the Maze procedure are identical in patients who have early postoperative atrial fibrillation and in those who do not.4,9 Therefore, we treat this early postoperative atrial fibrillation with appropriate drug therapy as it occurs, with the expectation that by 6 weeks to 3 months postoperatively, the need for the drugs will disappear, just as it usually does after other types of cardiac surgery. At 3 months postoperatively, however, all medications are discontinued. The definition of a
Mitral Valve Surgery and Maze III Procedure
“success” or “cure” of atrial fibrillation that we have always applied to indicate a surgical cure of atrial fibrillation is as follows. If the patient has a documented episode of atrial flutter or atrial fibrillation beyond 3 months after surgery, it is considered a recurrence. This is an unusually strict criterion for failure of a surgical procedure, but it is what we have used since the beginning of our series. Using this criterion for arrhythmia recurrence, we have had an overall recurrence rate after the Maze III procedure of 2% to 4%, and 50% of those patients have subsequently been converted and maintained free of atrial fibrillation and/or atrial flutter by medical therapy. A controversy that has arisen during the past several years is whether or not the Maze procedure is as effective when applied for atrial fibrillation associated with valvular heart disease as it is when applied for atrial fibrillation unassociated with other cardiac disease. For reasons already mentioned, most of our early patients underwent the Maze procedure for “lone atrial fibrillation.” Perhaps because of a reluctance in most centers to refer patients to surgery for atrial fibrillation alone, the Maze procedure experience reported by others has frequently included a majority of patients with associated mitral valve disease.10-13 Because the results attained by some groups in such patients were less than optimal,11,12 their arrhythmia recurrence rates after the Maze procedure of 20% to 30% were attributed to an assumed difference in atrial histopathology in the presence of mitral valve disease. We have always believed, however, that the difference in results was because the Maze procedure was being performed incorrectly or incompletely in those patients,14 especially in view of the fact that our own experience, as well as that of certain other groups,12,13,15,16 indicated that the Maze procedure was just as effective for atrial fibrillation associated with mitral valve disease as it was for lone atrial fibrillation. The results of our present analysis confirm that belief. Our initial concern regarding the potential increased risk of performing the Maze procedure concomitantly with other cardiac surgical procedures has proven unwarranted. This analysis of our series, however, has demonstrated that one should be cautious when contemplating the possibility of combining the Maze procedure with mitral valve surgery in elderly patients. Nevertheless, it is also important to recognize that
209
these patients carry a substantial operative risk for cardiac surgery whether or not a Maze procedure is added for the treatment of associated atrial fibrillation.17
References 1. Cox JL, Schuessler RB, D’Agostino H.J Jr, et al: The surgical treatment of atrial fibrillation. III: Development of a definitive surgical procedure. J Thorac Cardiovasc Surg 101:569-583, 1991 2. Cox JL: The surgical treatment of atrial fibrillation. IV: Surgical technique. J Thorac Cardiovasc Surg 101:584592, 1991 3. Cox, JL, Boineau JP, Schuessler RB, et al: Successful surgical treatment of atrial fibrillation. JAMA 266:19761980, 1991 4. Cox JL, Boineau JP, Schuessler RB, et al: Five-year experience with the Maze procedure for atrial fibrillation. Ann Thorac Surg 56:814-824, 1994 5. Cox, JL: The minimally invasive Maze procedure for the treatment of atrial fibrillation. Op Tech Thorac Cardiovasc Surg, 5:79, 2000 6. Haissaguerre M, Jais P, Shah DC, et al: Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med 339:659-666, 1998 7. Cox JL, Ad N: New surgical and catheter-based modification of the Maze procedure. Semin Thorac Cardiovasc Surg 12:68-73, 2000 8. Ad N, Suyderhoud JP, Kim YD, et al: Prophylactic continuous infusion of furosemide benefits patients following the Maze procedure for atrial fibrillation. J Thorac Cardiovasc Surg 123(2):232-236, 2002 9. Cox JL, Scheussler RB, Lappas DG, et al: An 8.5-year clinical experience with surgery for atrial fibrillation. Ann Surg 224:267-275, 1996 10. Kawaguchi AT, Kosakai Y, Sasako Y, et al: Risks and benefits of combined Maze procedure for arial fibrillation associated with organic heart disease. J Am Coll Cardiol, 28:985-990, 1996 11. Kawaguchi AT, Kosakai Y, Isobe F, et al: Factors affecting rhythm after the Maze procedure for atrial fibrillation. Circulation, 94(suppl):III39-III42, 1996 12. Handa N, Schaff HV, Morris JJ, et al: Outcome of valve repair and Cox maze procedure for mitral regurgitation and associated atrial fibrillation. J Thorac Cardiovasc Surg 118:628-635, 1999 13. Schaff HV, Dearani JA, Daly RC, et al: Cox-Maze procedure for atrial fibrillation: Mayo Clinic experience. Semin Thorac Cardiovasc Surg 12:30-37, 2000 14. Cox JL, Ad N: The importance of cryoablation of the coronary sinus during the Maze procedure. Semin Thorac Cardiovasc Surg 12:20-24, 2000 15. McCarthy PM, Gillinov AM, et al: The Cox-Maze Procedure: The Cleveland Clinic Experience. Semin Thorac Cardiovasc Surg 12:25-29, 2000. 16. Arcidi JM, Doty DB, et al: The Maze Experience: The LDS Hospital Experience. Semin Thorac Cardiovasc Surg 12:38-43, 2000. 17. Society of Thoracic Surgeons: National Adult Cardiac Surgery Database, 1998.
I
n our initial clinical experience with the Maze procedure, we purposely avoided operating on patients who might need concomitant valve surgery. We did this because we felt that the complexity of the Maze procedure would cause increased operative time, and thus the combined procedure would be unsafe.1-4 Therefore, only after accumulating substantial experience with the Maze procedure alone did we apply it in combination with valve surgery. In recent years, we simplified the surgical procedure by abandoning the classical “cut-and-sew” technique and adopting a cryosurgical technique that we had introduced for the minimally invasive Maze procedure.5 With this new approach, we apply the same atrial lesions as in the cutand-sew technique, but use cryothermia to create the lesions. In addition, to avoid isolating so much of the normal left atrium between the right and left pulmonary veins, we no longer encircle all four pulmonary veins together, but rather encircle the right pulmonary veins as a unit and the left pulmonary veins as a unit. The efficacy of this modification is not affected by the work of From the Hadassah University Hospital, Jerusalem, Israel and the World Heart Foundation, Washington, DC. Address reprint requests to Niv Ad, MD, Thoracic and Cardiovascular Surgery, Hadassah University Hospital, Jerusalem 91120, Israel. Copyright 2002, Elsevier Science (USA). All rights reserved. 1043-0679/02/1403-0000$35.00/0 doi:10.1053/stcs.2002.34395
206
Hassiguerre et al6 on the origin of premature beats within the pulmonary veins that initiate paroxysmal atrial fibrillation. The current report of our results includes only those patients who underwent the Maze III procedure with or without its latest modifications when combined with mitral valve surgery.
Methods Patient Data Between July 1, 1997 and September 1, 2001, 53 patients underwent the Maze III procedure (hereafter referred to simply as the “Maze procedure”) combined with mitral valve surgery alone (44 patients) or combined with mitral valve surgery and tricuspid valve repair (9 patients). Four patients underwent the procedure as a “redo” operation. The average duration of the arrhythmia before it was treated surgically was 4.7 years (range, 0.5 to 20 years) for the paroxysmal atrial fibrillation group and 3.4 years (range, 6 months to 40 years) for the chronic atrial fibrillation group (Table 1). All of the patients had failed medical therapy before surgery; 44% of the patients had failed amiodarone therapy as well. The major indications for applying the Maze procedure in combination with mitral valve surgery were arrhythmia intolerance in 75% (40 of 53), drug intolerance in 15% (8 of 53), and previous thromboembolic event in 10% (5 of 53).
Seminars in Thoracic and Cardiovascular Surgery, Vol 14, No 3 ( July), 2002: pp 206-209
Mitral Valve Surgery and Maze III Procedure
Table 1. Patient Demographics Parameter
Maze Plus Mitral Valve Surgery
Average age (years) 59 ⫾ 13.3 (17 to 76 years) Female gender 45% Paroxysmal atrial fibrillation 41% Duration (years) 4.7 (6 months to 20 years) Chronic atrial fibrillation 59% Duration (years) 3.4 (0.5 year to 40 years) Previous surgery 7.5% (4 patients) Previous stroke/TIA 10% (5 patients) Rheumatic heart disease 15% (8 patients)
Fifty-three patients underwent 62 valve operations, including 37 mitral valve repairs, 39 mitral valve replacements, and 9 tricuspid valve repairs (Table 2). In 16 patients the procedure was done using cryothermal energy to perform the atrial lesions, and in 17 patients the procedure was done as a minimally invasive operation via a small right anterior thoracotomy.
Operative Technique The patient was placed in the standard supine position for the median sternotomy approach or in the right anterolateral position for the minimally invasive approach. The operation was carried out using cardiopulmonary bypass via separate caval cannulation with aortic (median sternotomy) or femoral artery (minimally invasive) cannulation. The patient was systemically cooled to 28°C, and the heart was initially arrested using antegrade warm-blood cardioplegia, followed by antegrade and retrograde cold-blood cardioplegia thereafter. In the beginning of the series, the Maze procedure was performed using the cut and sew technique.2 Later in the series, it was done using cryothermal energy7 for placing the atrial lesions.
Follow-Up The patient was returned to the care of his or her referring physician after hospital discharge. Because most of our patients were from long distances away, we followed them primarily by telephone for the first several weeks and then had them return for a formal evaluation 6 months after surgery (see below)
207
Anticoagulant Regimen Patients undergoing combined mitral valve surgery and the Maze procedure received anticoagulation therapy with sodium warfarin according to the type of mitral valve surgery that they underwent. Patients who had mitral valve repair or mitral valve replacement with a biologic valve were anticoagulated for 3 months. Those who had mitral valve replacement with a mechanical valve were anticoagulated for life. Six-Month Postoperative Evaluation By 6 months postoperatively, the patients had been off all antiarrhythmic medications for 3 months and had recuperated sufficiently from surgery to allow evaluation. At that time, they all underwent the following battery of tests: standard electrocardiography, 24-hour Holter monitoring, exercise stress test, and transthoracic echocardiography. The objectives of these tests were to document that (1) the patient is in a normal sinus rhythm or an atrioventricular (AV)paced rhythm with restoration of normal AV activation, (2) there are no persistent arrhythmias, (3) the chronotropic response of the sinus node (or pacemaker) is normal, and (4) both the right and left atria are contracting (documented A waves). If transthoracic echocardiography failed to detect the latter, especially function in the left atrium, then an immediate transesophageal echocardiography was performed. Because our previous experience had shown a high incidence of false-negative results using transthoracic echocardiography, we used this test as a screening device but not as the final arbiter of whether or not left atrial function was present after the Maze procedure.
Table 2. Types of Concomitant Surgery Combined With the Maze Procedure Surgical Procedure Mitral valve repair combined with the Maze procedure Redo mitral valve repair Combined with tricuspid valve repair Mitral valve replacement combined with the Maze procedure Redo mitral valve replacement Combined with tricuspid valve repair
Number of Patients 28 1 5 25 3 4
Ad and Cox
208
Table 4. Univariate Analysis for Predictors of Perioperative Death
Results Perioperative Results The mortality rate for patients undergoing combined mitral valve surgery and the Maze procedure was 3.8 % (2 of 53 patients) (Table 3). The one male and one female who died were both older than 70, and neither underwent a “redo” procedure. One had a cryosurgical Maze procedure combined with mitral valve replacement, and the other had a minimally invasive mitral valve repair plus the Maze procedure. Multivariate analysis of different parameters revealed no significant predictors for operative mortality, although this group of patients is relatively small (Table 4). Of particular interest is the incidence of perioperative atrial arrhythmias of 34% (18 patients). No perioperative strokes or transient ischemic attacks (TIAs) occurred in the group undergoing the Maze procedure and concomitant valve surgery. Fluid retention has been a significant problem in the past and occurred in 10% of our patients, but is no longer a problem because of the aggressive diuretic protocol that we now follow in all of our patients.8 A total of 10 patients required a new permanent pacemaker after the surgical procedure, 2 due to complete AV block and 8 (16%) due to preexisting sinus node dysfunction.
Parameter
P Value
Year of surgery Gender Age Duration of atrial fibrillation Type of atrial fibrillation Previous TIA/stroke Preoperative amiodarone Preoperative beta-blockers Preoperative diuretics Preoperative congestive heart failure Preoperative left ventricular ejection fraction Preoperative renal failure Preoperative chronic obstructive pulmonary disease Preoperative hypertension Preoperative diabetes mellitus Redo procedure Minimally invasive procedure Cryosurgical procedure
0.4 0.4 0.6 0.1 0.9 0.4 0.3 0.4 0.8 0.7 0.7 0.8 0.4 0.2 0.1 0.85 0.35 0.25
after the procedure; the arrhythmia was controlled by medication in only one of these patients, meaning that 98% of the patients had their arrhythmia abolished. No late strokes or TIAs occurred during the follow-up period.
Discussion
Late Results The mean follow-up time for this group is 2.8 ⫾0.9 years (range, 4 months to 4 years and 4 months). There was one late death (2%) not related to the Maze procedure. This was a 58-yearold male who underwent valve replacement with a mechanical valve and developed prosthetic valve endocarditis 7 weeks after surgery. Two patients (4%) had documented atrial arrhythmia
Table 3. Early Results for Combined Mitral Valve Surgery and the Maze III Procedure Complication
Percentage
Atrial arrhythmia Perioperative bleeding Stroke TIA New pacemaker (total) Sinus node dysfunction Operative death
34 6.5 0 0 10 8 3.8
Approximately 40% of patients who undergo the Maze procedure for atrial fibrillation experience typical postoperative atrial fibrillation in the immediate postoperative period for reasons outlined earlier. We consider the first 3 months after surgery to be the period needed for the atrium to heal from the surgery and for the local refractory periods in the atrium, which determine the vulnerability to atrial fibrillation, to return to their baseline preoperative values.4 We have learned that the long-term results of the Maze procedure are identical in patients who have early postoperative atrial fibrillation and in those who do not.4,9 Therefore, we treat this early postoperative atrial fibrillation with appropriate drug therapy as it occurs, with the expectation that by 6 weeks to 3 months postoperatively, the need for the drugs will disappear, just as it usually does after other types of cardiac surgery. At 3 months postoperatively, however, all medications are discontinued. The definition of a
Mitral Valve Surgery and Maze III Procedure
“success” or “cure” of atrial fibrillation that we have always applied to indicate a surgical cure of atrial fibrillation is as follows. If the patient has a documented episode of atrial flutter or atrial fibrillation beyond 3 months after surgery, it is considered a recurrence. This is an unusually strict criterion for failure of a surgical procedure, but it is what we have used since the beginning of our series. Using this criterion for arrhythmia recurrence, we have had an overall recurrence rate after the Maze III procedure of 2% to 4%, and 50% of those patients have subsequently been converted and maintained free of atrial fibrillation and/or atrial flutter by medical therapy. A controversy that has arisen during the past several years is whether or not the Maze procedure is as effective when applied for atrial fibrillation associated with valvular heart disease as it is when applied for atrial fibrillation unassociated with other cardiac disease. For reasons already mentioned, most of our early patients underwent the Maze procedure for “lone atrial fibrillation.” Perhaps because of a reluctance in most centers to refer patients to surgery for atrial fibrillation alone, the Maze procedure experience reported by others has frequently included a majority of patients with associated mitral valve disease.10-13 Because the results attained by some groups in such patients were less than optimal,11,12 their arrhythmia recurrence rates after the Maze procedure of 20% to 30% were attributed to an assumed difference in atrial histopathology in the presence of mitral valve disease. We have always believed, however, that the difference in results was because the Maze procedure was being performed incorrectly or incompletely in those patients,14 especially in view of the fact that our own experience, as well as that of certain other groups,12,13,15,16 indicated that the Maze procedure was just as effective for atrial fibrillation associated with mitral valve disease as it was for lone atrial fibrillation. The results of our present analysis confirm that belief. Our initial concern regarding the potential increased risk of performing the Maze procedure concomitantly with other cardiac surgical procedures has proven unwarranted. This analysis of our series, however, has demonstrated that one should be cautious when contemplating the possibility of combining the Maze procedure with mitral valve surgery in elderly patients. Nevertheless, it is also important to recognize that
209
these patients carry a substantial operative risk for cardiac surgery whether or not a Maze procedure is added for the treatment of associated atrial fibrillation.17
References 1. Cox JL, Schuessler RB, D’Agostino H.J Jr, et al: The surgical treatment of atrial fibrillation. III: Development of a definitive surgical procedure. J Thorac Cardiovasc Surg 101:569-583, 1991 2. Cox JL: The surgical treatment of atrial fibrillation. IV: Surgical technique. J Thorac Cardiovasc Surg 101:584592, 1991 3. Cox, JL, Boineau JP, Schuessler RB, et al: Successful surgical treatment of atrial fibrillation. JAMA 266:19761980, 1991 4. Cox JL, Boineau JP, Schuessler RB, et al: Five-year experience with the Maze procedure for atrial fibrillation. Ann Thorac Surg 56:814-824, 1994 5. Cox, JL: The minimally invasive Maze procedure for the treatment of atrial fibrillation. Op Tech Thorac Cardiovasc Surg, 5:79, 2000 6. Haissaguerre M, Jais P, Shah DC, et al: Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med 339:659-666, 1998 7. Cox JL, Ad N: New surgical and catheter-based modification of the Maze procedure. Semin Thorac Cardiovasc Surg 12:68-73, 2000 8. Ad N, Suyderhoud JP, Kim YD, et al: Prophylactic continuous infusion of furosemide benefits patients following the Maze procedure for atrial fibrillation. J Thorac Cardiovasc Surg 123(2):232-236, 2002 9. Cox JL, Scheussler RB, Lappas DG, et al: An 8.5-year clinical experience with surgery for atrial fibrillation. Ann Surg 224:267-275, 1996 10. Kawaguchi AT, Kosakai Y, Sasako Y, et al: Risks and benefits of combined Maze procedure for arial fibrillation associated with organic heart disease. J Am Coll Cardiol, 28:985-990, 1996 11. Kawaguchi AT, Kosakai Y, Isobe F, et al: Factors affecting rhythm after the Maze procedure for atrial fibrillation. Circulation, 94(suppl):III39-III42, 1996 12. Handa N, Schaff HV, Morris JJ, et al: Outcome of valve repair and Cox maze procedure for mitral regurgitation and associated atrial fibrillation. J Thorac Cardiovasc Surg 118:628-635, 1999 13. Schaff HV, Dearani JA, Daly RC, et al: Cox-Maze procedure for atrial fibrillation: Mayo Clinic experience. Semin Thorac Cardiovasc Surg 12:30-37, 2000 14. Cox JL, Ad N: The importance of cryoablation of the coronary sinus during the Maze procedure. Semin Thorac Cardiovasc Surg 12:20-24, 2000 15. McCarthy PM, Gillinov AM, et al: The Cox-Maze Procedure: The Cleveland Clinic Experience. Semin Thorac Cardiovasc Surg 12:25-29, 2000. 16. Arcidi JM, Doty DB, et al: The Maze Experience: The LDS Hospital Experience. Semin Thorac Cardiovasc Surg 12:38-43, 2000. 17. Society of Thoracic Surgeons: National Adult Cardiac Surgery Database, 1998.