Current results of minimally invasive surgical ablation for isolated atrial fibrillation

Long-Term Results of the Mini Maze Standalone Bi-Atrial Surgical Ablation: A 10-Year Follow-Up

Background: One way to treat atrial fibrillation is through surgical ablation. However, the literature only provides information on patient follow-up results for up to 5 years. Methods: In order to assess long-term monitoring data over ten years, this retrospective study included 58 patients with paroxysmal or persistent atrial fibrillation who underwent Mini Maze surgical ablation at Santaros Clinics between 1 February 2009 and 1 June 2014. The follow-up time after surgery was 144 ± 48 months. We evaluated the absence of atrial fibrillation, echocardiographic and clinical parameters, and EHRA score. Results: Sinus rhythm remained in 69.4%, 75.5%, 55.6%, and 44.1% of patients with paroxysmal AF, and 68,2%, 59.1%, 50%, and 41.9% of patients with persistent AF (p = 0.681). In the post-operative period, one patient (1.7%) had a transient ischemic attack, and another patient (1.7%) had a thoracotomy for post-operative bleeding. A total of 20% of patients were diagnosed with a post-operative respiratory tract infection. EHRA scores showed that patients' quality of life improved after they underwent Mini Maze surgical ablation. Conclusions: Despite AF recurrences after surgery, quality of life remains better than before surgery, showing that Mini Maze surgery is an effective and safe second-line treatment method for atrial fibrillation.

The Minimum Number of Ablation Lines for Complete Isolation of the Pulmonary Veins during Thoracoscopic Ablation for Atrial Fibrillation

Total thoracoscopic ablation has been recommended as a class IIa indication for atrial fibrillation. However, the optimal number of ablation lines for pulmonary vein isolation has not yet been proposed. This study aimed to report the minimum number of ablation lines required to achieve an intraoperative conduction block. This study included a total of 20 patients who underwent total thoracoscopic ablation from December 2020 to July 2021. The epicardial conduction block was checked after each ablation line of pulmonary vein antral clamping. The median age was 61 years old. The median duration of atrial fibrillation since the first diagnosis was 78 months. Pulmonary vein isolation with bidirectional conduction block was confirmed in 90% of patients. A median of six ablation lines around each pulmonary vein antrum were performed according to our protocol even after the conduction block was verified. The median number of ablations to achieve an exit block was two on the right side and 3.5 on the left side. We found that most conduction blocks were achieved within three ablations around the pulmonary vein antrum. Our results may provide evidence to reduce the number of unnecessary ablation lines in the future.

Impact of left atrial box surface ratio on the recurrence after ablation for persistent atrial fibrillation

Background

The posterior wall of the left atrium (LA) is a well‐known substrate for atrial fibrillation (AF) maintenance. Isolation of the posterior wall between the pulmonary veins (box lesion) may improve ablation success. Box lesion surface area size varies depending on the individual anatomy. This retrospective study evaluates the influence of box lesion surface area as a ratio of total LA surface area (box surface ratio) on arrhythmia recurrence.

Methods

Seventy consecutive patients with persistent AF (63 ± 11 years, 53 men) undergoing computed tomography (CT) imaging and ablation procedure consisting of a first box lesion were included in this study. Box lesion surface area was measured on electroanatomical maps and total LA surface area was derived from CT. Patients were followed with 24‐h electrocardiography and exercise tests at 3, 6, and 12 months after AF ablation. Arrhythmia recurrence was defined as any AF/atrial tachycardia (AT) beyond 3 months without antiarrhythmic drugs.

Results

During a median follow‐up of 13 (interquartile range = 10‐17) months, 42 (60%) patients had AF/AT recurrence. Multivariate Cox proportional regression analysis showed that a larger box surface ratio protected against recurrence (hazard ratio [HR] = 0.81; 95% confidence interval [CI] = 0.690‐0.955; P = 0.012). Left atrial volume index (HR = 1.01 [0.990‐1.024, P = 0.427] and a history of mitral valve surgery (HR = 2.90; 95% CI = 0.970‐8.693; P = 0.057) were not associated with AF recurrence in multivariate analysis.

Conclusion

A larger box lesion surface area as a ratio of total LA surface area is protective for AF/AT recurrence after ablation for persistent AF.

European prospective multicentre study of hybrid thoracoscopic and transcatheter ablation of persistent atrial fibrillation: the HISTORIC-AF trial

OBJECTIVES

The HISTORIC-AF trial is a prospective, multicentre, single-arm study designed to evaluate the outcomes of a staged endoscopic and transcatheter ablation in patients with stand-alone, persistent or long-standing persistent atrial fibrillation (AF).

METHODS

From 2012 to 2015, 100 consecutive patients were enrolled and underwent thoracoscopic left atrial epicardial isolation ('box lesion') followed by transcatheter ablation in case of AF recurrency. The safety end point was the composite outcome of freedom from major adverse events at 30-days, while efficacy end points were: (i) primary: freedom from AF and stable sinus rhythm following isolated thoracospic ablation >60% and (ii) secondary: freedom from AF and stable sinus rhythm >80% following hybrid ablation (as per HRS criteria).

RESULTS

No death occurred and surgical thoracoscopic procedure was successfully completed in all patients. Survival free from major adverse events at 30 days was 94%: there were 3 permanent pacemaker implants, 2 episodes of stroke and 1 revision for bleeding. At discharge, 87% of patients were in sinus rhythm. A staged transcatheter ablation was carried out in all patients with AF recurrences at the end of 3 months blanking period (17% of patients). At 12-months follow-up, a stable restoration of sinus rhythm was achieved in 75% and 88% of patients following isolated thoracoscopic ablation and hybrid ablation, respectively.

CONCLUSIONS

The HISTORIC-AF trial showed that thoracoscopic isolated surgical ablation reached both the safety and the efficacy end points. Hybrid ablation steadily improved rhythm outcomes and may be considered in the future as the treatment of choice for patients with persistent and long-standing persistent AF.

ClinicalTrials.gov Identifier

NCT01622907.

Atrial fibrillation: review of current treatment strategies

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in modern clinical practice, with an estimated prevalence of 1.5-2%. The prevalence of AF is expected to double in the next decades, progressing with age and increasingly becoming a global medical challenge. The first-line treatment for AF is often medical treatment with either rate control or anti-arrhythmic agents for rhythm control, in addition to anti-coagulants such as warfarin for stroke prevention in patient at risk. Catheter ablation has emerged as an alternative for AF treatment, which involves myocardial tissue lesions to disrupt the underlying triggers and substrates for AF. Surgical approaches have also been developed for treatment of AF, particularly for patients requiring concomitant cardiac surgery or those refractory to medical and catheter ablation treatments. Since the introduction of the Cox-Maze III, this procedure has evolved into several modern variations, including the use of alternative energy sources (Cox-Maze IV) such as radiofrequency, cryo-energy and microwave, as well as minimally invasive thoracoscopic epicardial approaches. Another recently introduced technique is the hybrid ablation approach, where in a single setting both epicardial thoracoscopic ablation lesions and endocardial catheter ablation lesions are performed by the cardiothoracic surgeon and cardiologist. There remains controversy surrounding the optimal approach for AF ablation, energy sources, and lesion sets employed. The goal of this article is review the history, classifications, pathophysiology and current treatment options for AF.

Totally thoracoscopic ablation for treatment of atrial fibrillation after atrial septal defect device closure

Atrial septal defect (ASD) is one of the most common congenital heart defects in adults. Surgical repair is the most common treatment approach, but device closure has recently become widely performed in accordance with the trend toward less invasive surgical approaches. Although surgery is recommended when ASD is accompanied by atrial fibrillation, this study reports a case in which a complete cure was achieved by closure of a device and totally thoracoscopic ablation.

Positioning of the ablation catheter in total endoscopic ablation

Minimally invasive ablation of atrial fibrillation is an option in patients not suitable for or refractory to catheter ablation. Total endoscopic ablation can be performed via a monolateral approach, whereby a left atrial box lesion is created. If the ablation is introduced from the right side, the positioning of the ablation catheter on the partly hidden left pulmonary veins is of vital importance. Using thoracoscopy in combination with multiplane transoesophageal echocardiography, the anatomical position of the ablation catheter can be established. Our experience in over 60 procedures has confirmed this to be a safe technique of total endoscopic ablation.

Stand alone surgical ablation for atrial fibrillation

BACKGROUND

Trials to maintain sinus rhythm in patients with atrial fibrillation (AF) and refractory symptoms have been complicated by lack of success or intolerance of medications. Experience with minimally invasive AF surgery is relatively new, and early results have been promising. However, the study populations and techniques were heterogeneous, and the follow-up periods were short in many series.

METHODS

We present a single center experience through a retrospective review of medical records of patients who had minimally invasive AF surgery.

RESULTS

The surgical techniques addressed several possible mechanisms of AF and causes of recurrence, including pulmonary vein isolation, underlying substrates modification, ligament of Marshall interruption, ganglion plexus ablation, and left atrial appendage exclusion. Thirty-three cases were identified. The mean duration of follow-up was 23.2 months, and 58.6% were maintained in a sinus rhythm and were off antiarrhythmic drugs at the end of the follow-up period. Cases with persistent AF had a lower success rate.

CONCLUSION

Results with minimally invasive surgery are suboptimal at two years of follow-up, particularly for patients with persistent AF.

Totally Thoracoscopic Surgical Ablation or Catheter Ablation of Atrial Fibrillation: A Systematic Review and Preliminary Meta-Analysis

This article provides results of a preliminary meta-analysis of the stand-alone atrial fibrillation (AF) surgical publications from 2009 to 2011. In 6 studies with postoperative freedom from AF as primary end point, the meta-analysis indicated an overall success rate of 84% (95% confidence interval [CI], 80.0-88.0). For the 7 studies with the primary end point of postoperative return to normal sinus rhythm, the success rate was 83% (95% CI, 79.0-87.0). These data are compared with 3 comprehensive meta-analyses of catheter ablation. Based on comparison, it is recommended that initial treatment of long-standing persistent atrial fibrillation be minimal access surgery.

A review of current surgical treatment of patients with atrial fibrillation

Surgical therapy for patients with atrial fibrillation has undergone significant advances over the past 30 years. The Cox Maze III technique is currently the gold standard of care for these patients. However, Maze IV, a less complex procedure using alternative energy sources, is rapidly replacing the Cox Maze III in clinical practice. The use of alternative energy sources such as cryothermy and radiofrequency eliminates some of the "cut and sew" lesions of the Maze III, resulting in an easier and faster procedure with less morbidity. Video-assisted technology and hybrid procedures have further ushered in the future of surgical therapy. This article presents the latest surgical therapeutic options for patients with atrial fibrillation. The history of these procedures is presented, followed by a discussion of modern-era techniques, including concomitant ablation and standalone (also referred to as "lone") procedures. Finally, the article explores breaking developments and future directions for the surgical treatment of patients with atrial fibrillation.