Title: Long follow-up the effectiveness of thoracoscopic ablation of persistent and long-standing atrial fibrillation

Abstract:

Statement of the Problem. Atrial fibrillation (AF) has been identified as one of the most common arrhythmias in clinical setting. The prevalence of AF in adults is estimated to be between 1-2% currently, which is expected to increase by two- to threefold due to extended life expectancy [1, 2]. An important issue in modern arrhythmology is the search for highly effective, minimally invasive treatments for isolated non-paroxysmal AF, which represents up to 70% [3].

The purpose of this study is to evaluate the efficacy of thoracoscopic ablation (TSA) of persistent and long-standing atrial fibrillation in the long-term follow-up period.

Material & methods. From 2019 to 2021 years, 50 patients with persistent (I group) and 50 long-standing AF (II group) underwent TSA and exclusion left atrial appendage (LAA). Patients with paroxysmal AF, any organ heart pathology and decompensated conditions were not included in the study. The effectiveness of the procedure was defined as the absence of any atrial tachycardia (AF, supraventricular tachycardia, atrial flutter) documented on an ECG or on a 24-h HM ECG more than 30 seconds.

Surgical procedure. The procedure was performed according to the "Box lesion set" with additional linear ablations along the posterior wall of the left atrium (LA) and in projections of the ganglion plexus. Isolation of pulmonary vein (PVI) was performed using an ablative bipolar clamp (AtriCure, Inc., West Chester, Ohio, USA). LAA exclusion was performed through one of the left-sided ports using an endostapler, monitored by transesophageal echocardiography (Figure 1). Transmurality and the achievement of bidirectional conduction through the ablation lines performed (exit and entry block) were assessed at all stages of surgery.   

Results. Median age of patients was 58 (51-63) years and 56 (48-62.75) years, with a male domination of 75% (n=33) and 70.83% (n=34) in groups I and II, respectively. There was a statistically significant difference between the groups preoperatively only for the duration of AF of 2.25 (0.77-5) years in group I and 5 (2-8) years in group II (p=0.001*).

The mean follow-up period of the patients was 2.8±0.7 years. The overall efficacy of TSA after 3, 6 and 12 months was 82.7%, 81.6%, 73.5%, respectively. In the long-term follow-up period, freedom from AF was 70.7%.

Efficiency of epicardial ablation of persistent AF was 86.0% and 78.0%, and of long-standing AF 77.1% and 68.8% after 6 and 12 months, respectively (p=0.14).

Discussion. The heterogeneity of patients included in early studies makes it difficult to interpret the efficacy of TSA of persistent and long-standing AF. Whether additional lines of ablation outside the "Box lesion set" improve the efficacy of TSA is not fully understood [4]. The surgical protocol presented in our study was supplemented with ablation lines along the posterior wall of the LA and in the projection of the ganglion plexus, which improved the efficacy of TSA in the long-term follow-up to 70.7% compared with the data where ablations were performed exclusively according to the "Box lesion set" [5].  

Conclusion. Videoassisted thoracoscopic ablation of atrial fibrillation should be considered a promising method of arrhythmia management in patients with persistent and long-standing atrial fibrillation. Additional linear ablations along the posterior wall of the left atrium and in the projection of the ganglion plexus significantly improve the effectiveness of the procedure in the long-term follow-up.

Biography:

Elizaveta Strebkova (28 years). She graduated with honors from the Kursk State Medical University, than She graduated from a residency by cardiovascular surgery from the A.V. Vishnevskiy National Medical Research Center of Surgery in 2021 and wished to continue studying, went on for a Post Graduate by cardiovascular surgery and arrhythmology. The aim of her scientific work is “Effectiveness of thoracoscopic treatment of persistent and long-standing forms of atrial fibrillation”. She assist in all cardiac surgeries and take an active part in the scientific work our department. According to her work, theses and articles have been published. For the first time in our center, simultaneous two-way access is offered when performing thoracoscopic ablation, which significantly reduces the operation time.