Totally Thoracoscopic Left Atrial Maze Procedure

The Cox-Maze procedure is an effective and successful method of surgical ablation. However, for lone atrial fibrillation cases, invasive sternotomy is not feasible. Patients with persistent atrial fibrillation can benefit by combining left atrial endocardial and epicardial interventions.

This video presents multiple cases to highlight surgical steps of a totally thoracoscopic left atrial maze. The procedure was performed under general anesthesia with a double lumen endotracheal tube and single lung ventilation. Central venous access was obtained via a right internal jugular line and a transesophageal echo (TOE) probe was placed.

The patient was then placed in the supine position and external defibrillator pads were positioned anteriorly and posteriorly, close to the midline. Arms were positioned at a lower level on side boards, and the shoulders were shrugged. 

The instrumentation involved in the procedure are displayed in the video. The authors used optical entry ports of 5 mm, 12 mm, and a 10 mm zero degree telescope. The surgery required series of endoscopic instruments including endoscopic scissors, endoscopic graspers, and the knot pusher. It also required a variety of specialized devices.

To begin, surgeons entered the right thoracic cavity. Two 12 mm ports were placed in the fourth intercostal space midaxillary line and in the sixth intercostal space anterior axillary line, both directed toward the pericardium centrally. A third 5 mm port was then inserted under vision from the second intercostal space, close to the deltopectoral groove. CO2 insufflation at a pressure of 7 mmHg and 7 L/min of flow was given.

The optical ports allowed for safe entry into the thoracic cavity and the right phrenic nerve was visualized. The pericardium was incised 2 cm anterior to the phrenic nerve using a harmonic device, commencing between the aorta and the superior vena cava to avoid right atrial injury and extending anteriorly over the inferior vena cava. The pericardial stay sutures were taken with the Endo Stitch and retrieved via posterior axillary stab incision. The fascia between the superior vena cava and the pericardium was then gently dissected with an endoscopic peanut before taking a pericardial stitch superiorly.

Attention was then turned toward the oblique and transverse sinuses. Dissection was performed under direct vision using an endoscopic suction irrigation device and the endoscopic peanut, and sometimes the hook diathermy, to delineate the oblique and transverse sinuses. The transverse sinus was dissected gently along the left atrial roof and the pulmonary artery to the base of the left atrial appendage (LAA). To facilitate the pulmonary vein ablation, the transverse sinus was dissected further toward the posterior pericardium. The left atrial roof was dissected and the Waterston's groove was developed.

Ablation started on the roof of the left atrium using the AtriCure Coolrail device, with approximately eight to fifteen applications. The radiofrequency device algorithm showing adequate ablation was also used. Similar lesions set to the floor of the left atrium, joining the right and left inferior pulmonary veins, were then completed. Withdrawing the TOE probe prevented inadvertent injury to the esophagus.

A lighted dissector was then passed posterior to the right pulmonary veins. It broke through residual connective tissue at the roof of the transverse sinus. A plastic sleeve, delivered with the device, was retrieved and a catheter connected to a clamp was guided into position. The clamp was brought into the thoracic field and gently passed across the right pulmonary veins. Normally, the authors complete three pairs of ablation with radiofrequency.

The conduction block was then confirmed with help of the AtriCure MAX5 Isolator Pen. When the pulmonary vein is isolated effectively, there is no signal, which is denoted by a straight line without any activity or fluctuation. The guiding catheter was then directed across the transverse and oblique sinuses and placed into the left pericardium. The pericardium was then reapproximated. The team used the Endo Stitch, and the knots were tied with a knot pusher and cut with scissors. The authors usually placed a Blake drain in the right pleura and the right lung was re-expanded. Port closures were completed in a standard fashion.

Attention was then turned toward the left side. Port placements were similar to those on the right. The phrenic nerve was identified first and pericardiotomy was performed 1–2 cm posterior to the phrenic nerve. The guiding catheter was retrieved, and a second catheter was railroaded behind the left pulmonary veins. The left bipolar clamp was connected and directed into position across the left pulmonary veins to complete three pairs of lesions. Surgeons then checked for silence of activity with the help of the MAX5 isolator pen.

Identifying and dividing the Ligament of Marshall is an important step in atrial fibrillation surgery. To complete this step, the AtriCure Coolrail device was reintroduced and reinforcing lesions were performed to connect the roof and floor to the pulmonary veins and the base of the left atrial appendage. By this time, the guiding catheter was removed and the measuring apparatus—the Atriclip Selection Guide—was introduced to determine the correct AtriClip size. The AtriClip PRO2 device was then gently engaged on the left atrial appendage (LAA). Once engaged, surgeons waited for 30 seconds before disengaging the device to make sure there were no ECG or ischemic changes. They also confirmed the closure of LAA with the help of TOE. On disengaging, the LAA was ligated at the base.

Surgeons then placed a Blake drain in the left pleural cavity and the lungs were re-expanded. Finally, standard closure of port sites was completed.

References

1. Pick A, Kotschet E, Healy S, Adam D, Bittinger L. Hybrid totally thoracoscopic maze and catheter ablation for persistent atrial fibrillation: initial experience. Heart, Lung and Circulation. 2023;32(9):1107-1114. doi:10.1016/j.hlc.2023.06.002
2. Geuzebroek GSC, Bentala M, Molhoek SG, Kelder JC, Schaap J, Van Putte BP. Totally thoracoscopic left atrial Maze: standardized, effective and safe. Interactive Cardiovascular and Thoracic Surgery. 22(3):259-264. doi:10.1093/icvts/ivv358
3. Churyla A, Passman R, McCarthy PM, Kislitsina ON, Kruse J, Cox JL. Staged hybrid totally thoracoscopic maze and catheter ablation for atrial fibrillation. Journal of Cardiovascular Electrophysiology. 2022;33(8):1961-1965. doi:10.1111/jce.15594
4. Khoynezhad A, Ellenbogen KA, Al-Atassi T, et al. Hybrid atrial fibrillation ablation. Circulation: Arrhythmia and Electrophysiology. 2017;10(10). doi:10.1161/circep.117.005263
5. Haywood GA, Varini RK, Osmančík P, et al. European multicentre experience of staged hybrid atrial fibrillation ablation for the treatment of persistent and longstanding persistent atrial fibrillation. IJC Heart & Vasculature. 2020;26:100459. doi:10.1016/j.ijcha.2019.100459
6. Van Laar C, Geuzebroek GSC, Hofman FN, Van Putte BP. The totally thoracoscopic left atrial maze procedure for the treatment of atrial fibrillation. Multimedia Manual of Cardiothoracic Surgery. 2016;2016:mmv043. doi:10.1093/mmcts/mmv043

Disclaimer

The information and views presented on CTSNet.org represent the views of the authors and contributors of the material and not of CTSNet. Please review our full disclaimer page here.