BRIEF COMMUNICATION – ADULT CARDIAC
Interactive CardioVascular and Thoracic Surgery 18 (2014) 847–849 doi:10.1093/icvts/ivu035 Advance Access publication 26 February 2014
Left-sided mini-maze procedure via the left atrial appendage Issam Ismail†, Felix Fleissner†*, Serghei Cebotari, Saad Rustum and Axel Haverich Division of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany * Corresponding author. Division of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany. Tel: +49-511-5322184; fax: +49-511-5329833; e-mail: [email protected] (F. Fleissner). Received 18 July 2013; received in revised form 2 February 2014; accepted 4 February 2014
Abstract This study presents a novel way to perform the mini-maze procedure through the left atrial appendage. By this way, the usual additional incision of the intra-atrial groove is avoided, especially in patients receiving coronary artery bypass grafting (CABG) or aortic valve replacement without mitral valve disease. We retrospectively analysed 23 consecutive patients who received this novel mini-maze procedure between 2009 and 2011. In recognition of a learning curve, we divided the patients into two groups (Group 1: Patients 1–11 versus Group 2: Patients 12–23), according to the date of operation. In Group 2, 7 patients (58.33%) were completely free of atrial fibrillation at the time of the follow-up. In Group 1, only 2 (18.18%) patients were successfully treated resulting in a stable sinus rhythm at the time of the followup. The mini-maze procedure performed through the left atrial appendage is a safe and feasible technique; however, it seems to be less effective than the Cox-maze III procedure and is associated with a learning curve.
INTRODUCTION Atrial fibrillation (AF) is the most common arrhythmia. The Cox-maze III procedure is an efficient surgical treatment for AF [1]. Modifications to the Cox-maze III procedure, such as the isolated, left-sided maze operation, offers an easier, shorter and almost effective procedure for surgical treatment of AF [2]. During this procedure, the left atrium is opened via an interatrial groove incision. Because this procedure usually is followed by amputation of the left atrial appendage (LAA), our idea was to utilize this procedure through the LAA, omitting the additional incision of the intra-atrial groove.
METHODS This retrospective study included all 23 consecutive patients from January 2009 to August 2001 receiving the left-sided mini-maze procedure via the LAA.
Surgical procedure Three different senior surgeons performed all the operations. The procedure was performed via routine median sternotomy, under cardiopulmonary bypass using a two-stage venous cannula. After arresting the heart by use of cardioplegia, the heart was rotated to the right to expose the LAA. For atrial closure, the appendage was amputated, leaving a circumferential rim of 4 mm. The linear ablation was performed by using an irrigated unipolar radiofrequency probe (Cardioblate, Medtronic, Minneapolis, MN, USA). For better †
Both authors contributed equally to the study.
view of the right pulmonary veins, the right pleura was opened with the pericardial stay sutures loosened (Fig. 1). Subsequently, the left and the right pulmonary veins were isolated completely in a circular fashion. Three ablation lines were performed: One extended between both pulmonary veins islands, the second line from connection line between or the right pulmonary veins lesion to the pulmonary veins islands to the middle of the posterior mitral valve annulus and the third one was completed from the left pulmonary vein line to the base of the LAA. Then, the base of the LAA was carefully closed, using a double row of 4-0 polypropylene running suture. Subsequently, the intended cardiac repair and/or CABG was performed in routine fashion. The follow-up was complete with a median of 22 months (7–48 months). In recognition of a learning curve, we divided the patients into two groups: Group 1, Patients 1–11, and Group 2, Patients 12–23, according to the time of operation. The group follow-up for Group 1 was 32.4 months; for Group 2, it was significantly shorter with 11.6 months (P < 0.05). All patients gave consent to the follow-up, and the study was approved by the Ethics Committee of the Hannover Medical School. Patients were aware of the planned operation and gave their written consent. The results of the latest electrocardiogram (ECG) and Holter-ECG (or pacemaker readout) was requested. Patients to be called free of AF had at least two consecutive Holter-ECGs with no sign of AF. Ablation was considered successful if sinus rhythm (SR) was maintained with no symptomatic or documented episodes of AF or atrial flutter [3].
Statistical analysis Statistical analysis was performed using SPSS 19 package (SPSS, Inc., Chicago, IL, USA). The data were shown as mean + SD. Comparison of Groups 1 and 2 was performed using the unpaired
© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
BRIEF COMMUNICATION
Keywords: Mini maze • Atrial fibrillation • Left atrial appendage
848
I. Ismail et al. / Interactive CardioVascular and Thoracic Surgery
(47.83%) showed permanent AF [3]. One patient had cardiac pacemaker. The mean age was 76.61 years (see Table 1). All patients were on warfarin or full anticoagulation with low-molecularweight heparine before the operation. Ten patients received a biological aortic valve replacement, 2 of them with simultaneous replacement of the ascending aorta. Two patients received a mechanical aortic valve replacement and 4 patients underwent CABG. Of these, 3 received complete arterial revascularization using the radial artery and 1 patient received venous bypass grafts. Four patients received combined CABG and biological replacement of the aortic valve. Two patients received replacement of the ascending aorta alone, and 1 patient received a correction of a congenital displaced pulmonary vein. In the first 9 consecutive patients, the ischaemic time required to perform the left mini maze was 16 ± 3 min. For intraoperative and postoperative details, refer to Table 1. In recognition of a learning curve, we divided the patients into two groups: Group 1, Patients 1–11, and Group 2, Patients 12–23, according only to the time of operation. In Group 1, only 2 patients (18.18%) were successfully treated resulting in a stable SR at the time of the follow-up. In Group 2 (Patients 12–23), 7 patients (58.33%) had no signs of AF in multiple Holter-ECGs. Of all the patients before discharge from hospital and after 1 month, 39.13% (n = 9) of them showed a stable SR. At the time of the follow-up, 52.17% (n = 12) of all the patients had at least one or more ECGs showing a SR (or a pacemaker readout with no AF); however, some patients reported episodes of AF (documented on Holter-ECGs). In total, 9 patients (39.13%) had no sign of AF in at least two or more Holter-ECGs and were therefore classified as free of AF. During the follow-up, besides the 9 patients free of reoccurrence of AF, 7 patients presented with paroxysmal AF, 1 patient presented with persisting AF, whereas the others had permanent AF. Eight patients received one or more electric or medical conversions during the follow-up. No patient required implantation of a new permanent pacemaker postoperatively.
DISCUSSION
Figure 1: Operative procedure. (A) Resection of the left atrial appendage leaving a circumferential rim of 4 mm. (B) Exposure of the right pulmonary veins after incision of the right pleura and loosening of the stay sutures (arrow). (C) Exposure of the left pulmonary veins (arrow).
t-test or Fisher’s exact probability test with statistical significance assumed for P < 0.05.
RESULTS Patient characteristics: Of the 23 patients (female 7, male 16), 9 (39.13%) had paroxysmal AF, 3 (13.04%) had persisting AF and 11
In patients with AF, the Cox-maze III operation is the most curative therapy, with 70–90% success in restoration of SR [1, 4–6]. However, the Cox-maze III procedure is a complex operation that requires about an hour of cardiopulmonary bypass. Irrigated radiofrequency ablation as a left-sided mini-maze operation offers an easier, faster and almost effective procedure, with 57– 92% success rates in restoration of SR [7, 8], which are comparable with our results in Group 2. In the standard of the left-sided minimaze procedure, the left atrium is opened through an incision just posterior to the interatrial groove. Ablation lines are performed in order to isolate the pulmonary veins, and the LAA is either closed from inside or amputated followed by suture closure. Ligation or excision of the LAA is essential because most stroke-causing emboli in patients with AF originate from the LAA. Failure of the complete ligation of the LAA increases the risk of emboli [9, 10]. With the technique described herein, we could take advantage of this approach in that we utilized this incision for our modified maze procedure. Limitations to our study are the rather small sample size and the heterogeneous patient group. Due to study design, the patient received different numbers of Holter-ECGs, and the patient’s antiarrhythmic medication was not stopped for the follow-up. We also did not perform a standardized postoperative treatment for prevention of recurrence of AF with, for example, amiodarone. This could partly explain the less
I. Ismail et al. / Interactive CardioVascular and Thoracic Surgery
849
Table 1: Outcome after the mini-maze procedure performed via the left atrial appendage
Patients characteristics Age, years Sex, male Race n (Caucasian, %) Permanent atrial fibrillation Persistent atrial fibrillation Paroxysmal atrial fibrillation Previous PTCA/stent implantation Previous ablations atrial flutter Left atrial size (diameter, mm) Left ventricular ejection fraction Previous CABG Operational data Cross-clamp time, min CPB time, min Complications Rethoracotomya Stroke Outcome Sinus rhythm at discharge (%) Sinus rhythm at 1 month (%) Sinus rhythm at the last follow-up (%) Freedom of atrial fibrillation at the follow-up (%)
Total
Group 1
Group 2
P-valueb
76.61 ± 6.55 16 (69.56) 23 (100) 11 (47.83) 3 (13.04) 9 (39.13) 3 (13.04%) 2 (8.7) 46.9 (±8.31) 58.57 (±11.38) 1 (4.3)
79.09 ± 5.8 63.63% 11 (100) 4 (36.36) 2 (18.18) 5 (45.45) 2 (18.18) 1 (9.09) 46.67 ± 11.23 58.91 ± 11.18 1
72.42 ± 5.1 81.81% 12 (100) 5 (41.67) 1 (8.33) 6 (50.0) 1 (8.33) 1 (8.33) 47.09 ± 5.49 58.25 ± 12.05 0
Interactive CardioVascular and Thoracic Surgery 18 (2014) 847–849 doi:10.1093/icvts/ivu035 Advance Access publication 26 February 2014
Left-sided mini-maze procedure via the left atrial appendage Issam Ismail†, Felix Fleissner†*, Serghei Cebotari, Saad Rustum and Axel Haverich Division of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany * Corresponding author. Division of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany. Tel: +49-511-5322184; fax: +49-511-5329833; e-mail: [email protected] (F. Fleissner). Received 18 July 2013; received in revised form 2 February 2014; accepted 4 February 2014
Abstract This study presents a novel way to perform the mini-maze procedure through the left atrial appendage. By this way, the usual additional incision of the intra-atrial groove is avoided, especially in patients receiving coronary artery bypass grafting (CABG) or aortic valve replacement without mitral valve disease. We retrospectively analysed 23 consecutive patients who received this novel mini-maze procedure between 2009 and 2011. In recognition of a learning curve, we divided the patients into two groups (Group 1: Patients 1–11 versus Group 2: Patients 12–23), according to the date of operation. In Group 2, 7 patients (58.33%) were completely free of atrial fibrillation at the time of the follow-up. In Group 1, only 2 (18.18%) patients were successfully treated resulting in a stable sinus rhythm at the time of the followup. The mini-maze procedure performed through the left atrial appendage is a safe and feasible technique; however, it seems to be less effective than the Cox-maze III procedure and is associated with a learning curve.
INTRODUCTION Atrial fibrillation (AF) is the most common arrhythmia. The Cox-maze III procedure is an efficient surgical treatment for AF [1]. Modifications to the Cox-maze III procedure, such as the isolated, left-sided maze operation, offers an easier, shorter and almost effective procedure for surgical treatment of AF [2]. During this procedure, the left atrium is opened via an interatrial groove incision. Because this procedure usually is followed by amputation of the left atrial appendage (LAA), our idea was to utilize this procedure through the LAA, omitting the additional incision of the intra-atrial groove.
METHODS This retrospective study included all 23 consecutive patients from January 2009 to August 2001 receiving the left-sided mini-maze procedure via the LAA.
Surgical procedure Three different senior surgeons performed all the operations. The procedure was performed via routine median sternotomy, under cardiopulmonary bypass using a two-stage venous cannula. After arresting the heart by use of cardioplegia, the heart was rotated to the right to expose the LAA. For atrial closure, the appendage was amputated, leaving a circumferential rim of 4 mm. The linear ablation was performed by using an irrigated unipolar radiofrequency probe (Cardioblate, Medtronic, Minneapolis, MN, USA). For better †
Both authors contributed equally to the study.
view of the right pulmonary veins, the right pleura was opened with the pericardial stay sutures loosened (Fig. 1). Subsequently, the left and the right pulmonary veins were isolated completely in a circular fashion. Three ablation lines were performed: One extended between both pulmonary veins islands, the second line from connection line between or the right pulmonary veins lesion to the pulmonary veins islands to the middle of the posterior mitral valve annulus and the third one was completed from the left pulmonary vein line to the base of the LAA. Then, the base of the LAA was carefully closed, using a double row of 4-0 polypropylene running suture. Subsequently, the intended cardiac repair and/or CABG was performed in routine fashion. The follow-up was complete with a median of 22 months (7–48 months). In recognition of a learning curve, we divided the patients into two groups: Group 1, Patients 1–11, and Group 2, Patients 12–23, according to the time of operation. The group follow-up for Group 1 was 32.4 months; for Group 2, it was significantly shorter with 11.6 months (P < 0.05). All patients gave consent to the follow-up, and the study was approved by the Ethics Committee of the Hannover Medical School. Patients were aware of the planned operation and gave their written consent. The results of the latest electrocardiogram (ECG) and Holter-ECG (or pacemaker readout) was requested. Patients to be called free of AF had at least two consecutive Holter-ECGs with no sign of AF. Ablation was considered successful if sinus rhythm (SR) was maintained with no symptomatic or documented episodes of AF or atrial flutter [3].
Statistical analysis Statistical analysis was performed using SPSS 19 package (SPSS, Inc., Chicago, IL, USA). The data were shown as mean + SD. Comparison of Groups 1 and 2 was performed using the unpaired
© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
BRIEF COMMUNICATION
Keywords: Mini maze • Atrial fibrillation • Left atrial appendage
848
I. Ismail et al. / Interactive CardioVascular and Thoracic Surgery
(47.83%) showed permanent AF [3]. One patient had cardiac pacemaker. The mean age was 76.61 years (see Table 1). All patients were on warfarin or full anticoagulation with low-molecularweight heparine before the operation. Ten patients received a biological aortic valve replacement, 2 of them with simultaneous replacement of the ascending aorta. Two patients received a mechanical aortic valve replacement and 4 patients underwent CABG. Of these, 3 received complete arterial revascularization using the radial artery and 1 patient received venous bypass grafts. Four patients received combined CABG and biological replacement of the aortic valve. Two patients received replacement of the ascending aorta alone, and 1 patient received a correction of a congenital displaced pulmonary vein. In the first 9 consecutive patients, the ischaemic time required to perform the left mini maze was 16 ± 3 min. For intraoperative and postoperative details, refer to Table 1. In recognition of a learning curve, we divided the patients into two groups: Group 1, Patients 1–11, and Group 2, Patients 12–23, according only to the time of operation. In Group 1, only 2 patients (18.18%) were successfully treated resulting in a stable SR at the time of the follow-up. In Group 2 (Patients 12–23), 7 patients (58.33%) had no signs of AF in multiple Holter-ECGs. Of all the patients before discharge from hospital and after 1 month, 39.13% (n = 9) of them showed a stable SR. At the time of the follow-up, 52.17% (n = 12) of all the patients had at least one or more ECGs showing a SR (or a pacemaker readout with no AF); however, some patients reported episodes of AF (documented on Holter-ECGs). In total, 9 patients (39.13%) had no sign of AF in at least two or more Holter-ECGs and were therefore classified as free of AF. During the follow-up, besides the 9 patients free of reoccurrence of AF, 7 patients presented with paroxysmal AF, 1 patient presented with persisting AF, whereas the others had permanent AF. Eight patients received one or more electric or medical conversions during the follow-up. No patient required implantation of a new permanent pacemaker postoperatively.
DISCUSSION
Figure 1: Operative procedure. (A) Resection of the left atrial appendage leaving a circumferential rim of 4 mm. (B) Exposure of the right pulmonary veins after incision of the right pleura and loosening of the stay sutures (arrow). (C) Exposure of the left pulmonary veins (arrow).
t-test or Fisher’s exact probability test with statistical significance assumed for P < 0.05.
RESULTS Patient characteristics: Of the 23 patients (female 7, male 16), 9 (39.13%) had paroxysmal AF, 3 (13.04%) had persisting AF and 11
In patients with AF, the Cox-maze III operation is the most curative therapy, with 70–90% success in restoration of SR [1, 4–6]. However, the Cox-maze III procedure is a complex operation that requires about an hour of cardiopulmonary bypass. Irrigated radiofrequency ablation as a left-sided mini-maze operation offers an easier, faster and almost effective procedure, with 57– 92% success rates in restoration of SR [7, 8], which are comparable with our results in Group 2. In the standard of the left-sided minimaze procedure, the left atrium is opened through an incision just posterior to the interatrial groove. Ablation lines are performed in order to isolate the pulmonary veins, and the LAA is either closed from inside or amputated followed by suture closure. Ligation or excision of the LAA is essential because most stroke-causing emboli in patients with AF originate from the LAA. Failure of the complete ligation of the LAA increases the risk of emboli [9, 10]. With the technique described herein, we could take advantage of this approach in that we utilized this incision for our modified maze procedure. Limitations to our study are the rather small sample size and the heterogeneous patient group. Due to study design, the patient received different numbers of Holter-ECGs, and the patient’s antiarrhythmic medication was not stopped for the follow-up. We also did not perform a standardized postoperative treatment for prevention of recurrence of AF with, for example, amiodarone. This could partly explain the less
I. Ismail et al. / Interactive CardioVascular and Thoracic Surgery
849
Table 1: Outcome after the mini-maze procedure performed via the left atrial appendage
Patients characteristics Age, years Sex, male Race n (Caucasian, %) Permanent atrial fibrillation Persistent atrial fibrillation Paroxysmal atrial fibrillation Previous PTCA/stent implantation Previous ablations atrial flutter Left atrial size (diameter, mm) Left ventricular ejection fraction Previous CABG Operational data Cross-clamp time, min CPB time, min Complications Rethoracotomya Stroke Outcome Sinus rhythm at discharge (%) Sinus rhythm at 1 month (%) Sinus rhythm at the last follow-up (%) Freedom of atrial fibrillation at the follow-up (%)
Total
Group 1
Group 2
P-valueb
76.61 ± 6.55 16 (69.56) 23 (100) 11 (47.83) 3 (13.04) 9 (39.13) 3 (13.04%) 2 (8.7) 46.9 (±8.31) 58.57 (±11.38) 1 (4.3)
79.09 ± 5.8 63.63% 11 (100) 4 (36.36) 2 (18.18) 5 (45.45) 2 (18.18) 1 (9.09) 46.67 ± 11.23 58.91 ± 11.18 1
72.42 ± 5.1 81.81% 12 (100) 5 (41.67) 1 (8.33) 6 (50.0) 1 (8.33) 1 (8.33) 47.09 ± 5.49 58.25 ± 12.05 0
