Thoracoscopic infrared ablation to create a box lesion as a treatment for atrial fibrillation

Abstract BackgroundCreating a box lesion in the posterior wall of the left atrium from the epicardial side of the beating heart remains a challenge. Although a transmural lesion can be created by applying radiofrequency (RF) energy at clampable sites, there is still no reliable energy source to use to create a roof and bottom linear lesion to connect bilateral pulmonary vein (PV) cuff lesions produced with RF energy, because the inner blood flow in the unclampable free wall weakens the thermal effect on the outside. Our aim was to apply the newly developed infrared coagulator to create linear transmural lesions on the beating heart thoracoscopically to treat atrial fibrillation (AF).Case presentationA 71-year-old male was referred to our hospital with a diagnosis of hypertrophic cardiomyopathy and permanent atrial fibrillation. The patient was first diagnosed with atrial fibrillation 20 years before. Direct current cardioversion had been performed every few years a total of four times, but sinus rhythm restoration had always been temporary. The patient wanted to be free from anticoagulant therapy, symptom of palpitations, and fear of possibility of cerebral infarction. Transthoracic echography revealed no valvular dysfunction. Cardiac scintigraphy showed no evidence of myocardial ischemia. The electrocardiogram indicated AF with a 0.2 mV of f-wave amplitude. On February 27, 2020, thoracoscopic PV isolation together with infrared roof- and bottom-line ablation to create a box lesion and left atrial appendage amputation (LAAA) were performed. The coagulator could be applied to clinical thoracoscopic surgery to successfully create a box lesion without any complication. The patient restored a regular sinus rhythm, it has been maintained for eleven months, and there have been no adverse events. ConclusionsThe infrared coagulator might have enough potential to create transmural lesions on the beating heart in thoracoscopic AF surgery.