Contact force and ablation assessment of surgical bipolar radiofrequency clamps in the treatment of atrial fibrillation

Surgical Methods and Devices for Atrial Fibrillation

As technology advances, surgical approaches for atrial fibrillation have diversified. Surgical treatments include Cox-Maze surgery, left atrial appendage occlusion, or closure using a clip. Cox-Maze surgery removes excessive cardiac electrical conduction pathways, ensures electrical signals propagate exclusively through the predetermined maze channel and restores normal heart rhythm. Left atrial appendage closure reduces the risk of long-term disability or death caused by left atrial appendage thromboembolism in patients with atrial fibrillation. These devices are constantly being refined, including bipolar radiofrequency clamps (monopolar or bipolar radiofrequency), left atrial appendage closure devices (external excision using staplers, internal ligation with biomatrix patch occlusion, external device placement with the AtriClip and Endoloop ligature). In addition to surgical interventions, surgical biomaterial materials with biocompatibility and electrical conductivity have emerged in the basic research phase of atrial fibrillation treatment. This review delineates the primary surgical techniques, emphasizing their safety and efficacy in treating atrial fibrillation. An introduction to commonly used surgical equipment is provided as a reference for the clinical management of atrial fibrillation.

Radiofrequency and Cryoablation as Energy Sources in the Cox-Maze Procedure: A Meta-Analysis of Rhythm Outcomes

AIM

Cox-maze IV is the most effective surgical procedure for atrial fibrillation (AF) treatment to date; however, few studies have compared the outcomes of the different energy sources applied to achieve transmurality. This study aimed to analyse the impact of the different energy sources on Cox-maze IV results in terms of sinus rhythm restoration.

METHOD

A systematic review and meta-analysis was conducted by including studies reporting rhythm outcomes on biatrial Cox-maze AF ablation with bipolar radio-frequency (BRF), cryoenergy (Cryo), or both (BRF+Cryo). The primary endpoints were the early and late rhythm outcomes of AF ablation using the different energy sources. Late AF recurrences were evaluated through timepoint analysis, and freedom from AF from Kaplan-derived data. Sixty articles including 8,293 patients were selected (3,364 patients Cryo, 1,937 BRF, and 2,992 BRF+Cryo).

RESULTS

At 6 months, AF incidence was significantly lower in the Cryo group at 6.73%; it was 25.52% in the BRF and 16.79% in the BRF+Cryo groups (p=0.0112). At the 4-year timepoint, AF incidence was lower in the Cryo group compared with the BRF and BRF+Cryo: 6.14% vs 51.59% vs 16.09%, respectively (p=0.0392). Freedom from AF was 76.7%±2.2%, 60.9%±2.2%, and 66.3%±1.6% for Cryo, BRF, and BRF+Cryo at 4 years, respectively (p<0.001). At meta-regression, mean left atrial diameter was positively associated with higher AF recurrences (OR 1.04, 95% CI 1.01-1.08; p=0.0159).

CONCLUSION

When performing this procedure, cryoablation seems to be associated with improved rhythm outcomes when compared with bipolar radiofrequency ablation.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

Comparison of short-term efficacy of two bipolar radiofrequency ablation forceps for rheumatic heart disease concomitant with atrial fibrillation

Background

Currently, the bipolar radiofrequency ablation forceps manufactured by AtriCure are the main instrument for surgical ablation in patients with rheumatic heart disease (RHD) concomitant with atrial fibrillation (AF). The bipolar radiofrequency ablation forceps by Med-Zenith has a greater advantage in price compared with AtriCure. However, few studies have been reported on the comparison of their clinical efficacy. The aim of this study is to compare the short-term clinical efficacy of the two ablation forceps for RHD concomitant with AF.

Methods

Clinical data of 167 patients with RHD concomitant with AF admitted to the Department of Cardiac Major Vascular Surgery, Affiliated Hospital of North Sichuan Medical College, were retrospectively analyzed, and the restoration efficacy of sinus rhythm (SR) and cardiac function after surgery were compared with two ablation forceps.

Results

The end-systolic diameter of the right atrium and the end-systolic diameter of the left atrium in the patients of both groups at each postoperative time point decreased compared with that of the preoperative period (P < 0.05), and the left ventricular ejection fraction started to improve significantly at 6 months after surgery compared with that of the preoperative period (P < 0.05). There was no difference between the two groups of patients in the comparison of the aforementioned indicators at different points in time (P > 0.05). At 12 months postoperatively, the SR maintenance rate in using the ablation forceps by Med-Zenith (73.3%) was lower than that for AtriCure (86.4%) and the cumulative recurrence rate of AF in using the Med-Zenith ablation forceps was greater than that for AtriCure.

Conclusions

The two bipolar radiofrequency ablation forceps compared in the study are safe and effective in treating patients of RHD concomitant with AF, and the ablation forceps by AtriCure may be more effective in restoring SR in the short term.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Performance of a non-irrigated bipolar radiofrequency ablation clamp on beating human hearts

OBJECTIVE

This study is intended to examine the efficacy of a non-irrigated bipolar RF clamp and explore the factors that can influence its performance on beating human hearts using the electrophysiology mapping method.

METHODS

A total of 83 atrial fibrillation (AF) patients were included in this study. Based on the Body mass index (BMI, kg/m2), the AF patients were divided into the normal group (18.5 ≤ BMI < 25) and the overweight or obese group (BMI ≥ 25). They all underwent a stand-alone surgical ablation through our off-pump biatrial mini-maze procedure. After we completed each time of ablation, the achievement of PV isolation was checked using the electrophysiology mapping method. The number of ablation times to achieve the PV isolation on the left and right PVs was recorded respectively.

RESULTS

86.7% (72/83) PV isolation on the LPV and 72.3% (60/83) PV isolation on the RPV could be achieved respectively after performing a single time of surgical ablation. Three times of ablations resulted in 100.0% PV isolation on the left and right PVs. In the normal BMI group, the ratio of patients who achieved a complete PV isolation after a single time of ablation was 83.7% (36/43), which was higher than the 60.0% (24/40) in the overweight or obese group.

CONCLUSIONS

Performing three times of ablations resulted in 100% PV isolation on the left and right PVs. The bipolar RF clamp had a better performance on the LPV than on the RPV. The patients' BMI also influenced the Atricure clamp' s performance.

Performance of an Irrigated Bipolar Radiofrequency Ablation Clamp on Explanted Human Hearts

BACKGROUND

Bipolar radiofrequency (RF) clamps are commonly used during surgical ablation for atrial fibrillation (AF). This study examined the efficacy of an irrigated bipolar RF clamp to create transmural lesions in an ex vivo human heart model.

METHODS

Ten donor hearts, turned down for transplantation, were explanted and arrested with cold cardioplegia. The ablations of the Cox Maze IV procedure were performed using the Cardioblate LP (Medtronic, Inc) irrigated bipolar RF clamp. In the first 5 hearts, each lesion was created with a single application of RF, whereas in the remaining 5 hearts, each lesion was created with a double application of RF without unclamping. Each lesion was cross-sectioned and stained with 2,3,5-triphenyl-tetrazolium chloride to assess ablation depth and transmurality.

RESULTS

A total of 100 lesions were analyzed. In the single-ablation group, 222 of 260 sections (85%) and 37 of 50 lesions (74%) were transmural. The efficacy improved significantly in the double-ablation group, in which 348 of 359 sections (97%, P < .001) and 46 of 50 lesions (92%, P = .017) were transmural. Overall, in nontransmural lesions, the epicardial fat thickness was significantly greater (1.69 ± 0.70 mm vs 0.45 ±0.10 mm, P < .001) than the transmural lesions.

CONCLUSIONS

A single ablation on human atrial tissue with an irrigated bipolar RF clamp was insufficient to reliably create transmural lesions, but a double ablation significantly increased the lesion and section transmurality. Nontransmural lesions were associated with significantly thicker layers of epicardial fat, which likely decreased tissue energy delivery due to the higher resistance of fat to current flow.

Comparison of two radiofrequency ablation devices for atrial fibrillation concomitant with a rheumatic valve procedure

BACKGROUND

Perioperative and median-term follow-up outcomes have not been compared among procedures using radiofrequency ablation devices for permanent atrial fibrillation with concomitant rheumatic valve disease. We compared the sinus rhythm restoration efficacy of "non-irrigation" ablation forceps and an "irrigation" ablation device in patients with rheumatic valve disease undergoing a modified Cox maze radiofrequency ablation procedure due to permanent atrial fibrillation.

METHODS

Data of 278 patients with rheumatic valve disease from the Cardiac Surgery Department of Sichuan Provincial People's Hospital who underwent the modified Cox maze radiofrequency ablation procedure between May 2013 and May 2017 were reviewed. The procedure was performed using "non-irrigation" ablation forceps (AtriCure, group A) in 149 patients and an "irrigation" ablation device (Medtronic, group M) in 129 patients. Data were collected prospectively, and follow-up was documented and compared between the groups.

RESULTS

The radiofrequency procedure duration was 28.9 ± 3.8 min in group A and 29.5 ± 2.8 min in group M (t = 1.623, P = 0.106). The predicted radiofrequency time to the left atrium diameter was (Ya = 0.4964 X + 0.3762, R = 0.74) in group A and (Ym = 0.4331 X + 4.3563, R = 0.8435) in group M. The sinus rhythm (SR) conversion rate without use of anti-arrhythmic drugs was similarly good in groups A and M, with 75.2%, 72.5%, and 70.5% vs. 73.6%, 71.3%, and 69.8% at discharge, 6 and 12 months, respectively (F = 0.084, F = 0.046, F = 0.046, P > 0.05, respectively).

CONCLUSION

Two types of radiofrequency ablation devices characteristic of "non-irrigation" and "irrigation" bipolar ablation forceps were similarly efficient at SR restoration.