A Totally Thoracoscopic Ablation for Persistent Atrial Fibrillation
A 72-year-old female visited the emergency room because of a suddenly developed headache. The brain imaging studies revealed acute cerebral infarction. Further, the electrocardiography showed atrial fibrillation (AF). The echocardiography revealed that the mean left atrial dimension was 32.7 mm in the parasternal long axis view and 38.6 mm in the apical four-chamber view. The left ventricular ejection fraction was 86%. Transthoracic echocardiography revealed no intracardiac thrombus and normal valvular function. Amiodarone and coumadine were begun and maintained for the following five months. Just before the operation, the electrocardiogram still showed AF and the patient complained of palpitation and chest discomfort. We decided to perform thoracoscopic ablation. We performed transesophageal echocardiography after induction of anesthesia to rule out intracardiac thrombus. Before induction, defibrillator pads were placed appropriately. With the right lung deflated, the initial 10-mm port was placed in the sixth interspace at the anterior axillary line (). After thoracoscopic examination, two additional ports were inserted. Under thoracoscopic control, the pericardium was opened by electrocautery approximately 2 cm anterior to the right phrenic nerve. Pericardial traction was executed using an endoscopic suturing device (Endostitch; Covidien Inc., Norwalk, CT, USA). The oblique sinus was entered by gentle blunt dissection through the pericardial reflections under the inferior vena cava. A light dissector was used for encircling the pulmonary venous antrum. The antral area was ablated using a bipolar radiofrequency clamp (EMR; Atricure Inc., Cincinnati, OH, USA) (). The end point for pulmonary vein antral ablation was a complete exit block from the pulmonary veins. The autonomic ganglia plexuses (GPs) were ablated. High-frequency testing of the GPs was performed. Each of the testing sites was stimulated at a rate of 1,000 Hz and an amplitude of 18 V with at least a doubling of the R-R interval qualifying as a positive response. The right GP travels toward the right pulmonary veins and the interarterial groove. The left GP travels in the direction of the base of the left atrial appendage and the left upper pulmonary vein. Bipolar radiofrequency energy at 15 W was delivered through the bipolar pen (Isolator multifunctional pen; Atricure Inc.) to the GPs. After dissecting the transverse sinus, additional lines, which were a superior line through the transverse sinus and an inferior line through the oblique sinus, were made with the aid of a Cool Rail (Atricure Inc.). After the left lung was deflated, three trocars were inserted and were placed more posteriorly. Marshall's ligament was divided after left pericardiotomy. The previously performed line of ablation (superior line) across the transverse sinus was easily visualized and extended onto the left superior pulmonary vein, and the previously performed ablation line (inferior line) in the oblique sinus from the right chest was clearly identified. The linear probe created a line of ablation connecting the caudal margins of the two pulmonary isolation boxes (). The left atrial appendage exclusion was performed using a stapler (Ethicon Endo-Surgery Inc., Cincinnati, OH, USA) after the absence of flow was confirmed by intraoperative transesophageal echocardiography. Normal sinus rhythm was converted intraoperatively. A single chest tube was placed for draining each pleural space. The patient was extubated in the operating room. The operative time was 125 minutes. Postoperatively, coumadine and amiodarone were continued. The length of the hospital stay was 7 days. She resumed normal sinus rhythm two months after total thoracoscopic ablation, which was confirmed by 24-hour electrocardiogram monitoring.