Adam M Kingston, MD, Bruce G Hook, MD, Torin P Fitton, MD. Lahey Hospital and Medical Center
Atrial Fibrillation (AF) is a common problem with profound medical and economic impact. For men and women 40 years of age or older, the lifetime risk for development of AF is roughly 25% with annual costs for treatment estimated at $6.65 Billion in the United States. AF increases the lifetime risk of stroke nearly 5-fold and the development of persistent (Pe) and long-standing persistent (LSPe) AF is associated with an 8% per patient-year mortality risk. Open surgical treatment of AF, particularly in Pe or LSPe, have not been durable enough to justify the risks of open heart surgery. Thoracoscopic approaches and percutaneous catheter ablation, while certainly lessening surgical risk, have had disappointing outcomes in this group of patients. Historically, these patients’ only option has been long-term anticoagulation to prevent thromboembolic complications and rate control using a variety of different anti-arrhythmic protocols.
The Convergent procedure is a hybrid technique that uses minimally invasive laparoscopy to create epicardial lesions by a transdiaphragmatic approach. This avoids chest incisions, heart dissection, and cardiopulmonary bypass necessary for traditional open or thoracoscopic procedures. It is offered to complex patients in long-standing refractory atrial fibrillation or those who have failed prior endocardial ablation.
Abdominal laparoscopy is used by cardiac surgery teams to create a transdiaphragmatic pericardial window, permitting introduction of a pericardioscopy cannula and access to the posterior surface of the heart. Using radiofrequency (RF) energy, long, linear epicardial lesions are sequentially created across the posterior left atrium and then along the anterior left and right pulmonary veins. A pericardial drain is left in place overnight. An esophageal temperature probe is placed to prevent viscus injury during ablation. After the epicardial portion is complete, electrophysiology teams perform endocardial voltage mapping and ablation of any residual gaps, along the left atrial roof line and superior aspects of the pulmonary veins, as well as a right atrial lesion set. These procedures are performed entirely in the electrophysiology laboratory.
From December 2013 to December 2014, 34 convergent ablations were performed at the Lahey Hospital and Medical Center in Burlington, MA. Average patient age was 64.5 years old (64.7% male, 35.3% female). Mean hospital stay was 3.7 days. Overall conversion rate was 94.1% (32/34). Three patients (8.8%) were paced due to implanted devices but were not in presenting tachyarrhythmia at discharge. Two patients (5.9%) remained in atrial fibrillation with a plan for repeat cardioversion after recovery.
Convergent ablation is emerging as a safe and effective means for treating complex atrial fibrillation. Traditional surgical methods are less effective and costlier, with higher morbidity. Medical management carries the well-known risks of thromboembolism and chronic anticoagulation. By combining the skill sets of cardiac surgeons and electrophysiologists, convergent ablation has been established as a promising technique for the treatment of atrial fibrillation, and given the success rate, may become the standard of care.