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Robotic-assisted left atrial appendage occlusion
Atrial fibrillation poses significant stroke risks, particularly in patients undergoing cardiac surgery. Left atrial appendage occlusion has emerged as a crucial strategy for stroke prevention, garnering a Class I recommendation. This paper presents a technical framework for performing robotic left atrial appendage occlusion as an isolated procedure or concurrently with robotic coronary artery bypass grafting using the AtriCure AtriClip Pro2 device.
Patients with atrial fibrillation (AF) undergoing cardiac surgery face increased risks of thromboembolic complications, stroke and death [1, 2]. The left atrial appendage (LAA) is the primary site of emboli formation, prompting therapeutic focus initially on oral anticoagulation (OAC) [3, 4]. However, managing OAC intolerance and complications is challenging. Alternative strategies targeting LAA thrombus risk have shown comparable reductions in thromboembolic stroke incidence [5]. Factors like LAA anatomy (e.g., LAA’s too large or too small orifice diameter; LAA’s too shallow depth; too close proximity of a secondary LAA lobe, if present, to the LAA orifice) and contraindications to OAC may limit the use of endocardial LAA occlusion (LAAO) devices, while epicardial exclusion with a linear clip device like the AtriClip (Atricure Inc., Westchester, OH, USA) offers reliable closure. The LAAO has now become a Class I recommendation for high-stroke-risk patients with AF undergoing cardiac surgery [3, 4]. Therefore, every eligible patient should undergo LAAO, irrespective of the surgical approach. Robotic surgical platforms facilitate minimally invasive procedures, enabling LAAO in eligible patients regardless of LAA anatomy being deployed by a trocar with no thoracotomy incision. We present our technique used in cases of robotic LAA occlusion device deployment during robotic-assisted coronary artery bypass grafting (CABG).
1 - Patient Presentation (0:12)
The patient was a 46-year-old male with a past medical history significant for hypertension, paroxysmal atrial fibrillation previously controlled on flecainide and metoprolol, chronic lower extremity venous insufficiency and Raynaud's disease. After an abnormal result from a stress test and CT angiography of the heart, left heart catheterization showed an 80% mid-left anterior descending (LAD) stenosis and 90% proximal right coronary artery stenosis. During the procedure, he suffered from chest pain that prompted a stent in the right coronary artery. The LAD lesion had an instantaneous wave-free ratio of 0.83. After a multidisciplinary discussion, the decision was to offer the patient reverse hybrid coronary artery revascularization. The patient underwent robotic-assisted CABG with the left internal mammary artery to the LAD and the LAAO with a clip.
2 - Patient preparation (0:58)
The operation is conducted with the patient under general anaesthesia using single-lumen endotracheal intubation with a bronchial blocker. Following positioning of the patient on the operating table in a supine posture with slight elevation of the left hemithorax, the surgical field is prepared by disinfecting and covering it with sterile drapes. Three robotic 8-mm ports are positioned along the mid-clavicular line, in the second, fourth and sixth intercostal spaces. Carbon dioxide is infused at a pressure ranging from 6 to 10 mmHg.
Prior to robotic docking, a cryo nerve block under three to four ribs’ space is performed to temporarily block intercostal nerve conduction. The cryoprobe is positioned near the intercostal bundle (nerve, artery and vein), close to the innermost intercostal muscle, proximal to the laterocutaneous nerve branch, ensuring a minimum distance of 2 cm from the ganglia and 4 cm from the base of the spine. Gentle pressure is maintained on the tissue using the probe throughout the cryoablation procedure. Cryoablation is applied for 120 seconds at a temperature of –65 °C.
After robotic docking, optimization of robotic ports is performed for better visualization and manoeuvrability.
3 - Left atrial appendage preparation (1:52)
Prior to pericardial incision, the left phrenic nerve is identified. The pericardial sac is opened with an inferior phrenic incision and anterior to the left pulmonary veins. The opening is generous and moved cranially until reaching the pulmonary artery reflection with the pericardium. The left atrial appendage is completely visualized by lifting the pericardium. Through the pocking technique, the optimal intercostal space for introducing the AtriClip is selected based on the left atrial appendage position and extension. The last 12-mm working port is placed at the mid-axillary line. First, an 8-mm dilator is entered through the identified site, then a 12-mm dilator and finally the 12-mm AirSeal port (ConMed Corporation, Largo, FL, USA) is deployed in the final position. In our practice, the AirSeal access port works best for this purpose, due to the absence of valves and a specific system that maintains a stable pneumoperitoneum even with large leaks and heavy suction. A 4/0 polypropylene stitch is advanced through the AirSeal port The suture is placed on the anterior side of the pericardial opening to keep it in traction and to maximize LAA exposure. The traction suture is then brought out externally. The specific anatomical landmarks of the LAA are identified, which include the left circumflex artery, both pulmonary veins and the left pulmonary artery.
4 - Left atrial appendage occlusion (4:24)
Two soft pads are introduced via the AirSeal port to minimize injury to the left atrial appendage tissue during manipulation with robotic instruments. The appropriate LAA sizer included in the AtriClip kit is introduced via the 12-mm port, and the LAA stump is measured to determine the appropriate size of the AtriClip to deploy. In our specific case, a 40-mm AtriClip Pro 2 was utilized. The AtriClip is introduced into the working port using the proper delivery tool. After opening the clip, the LAA is gently positioned inside the clip with the aid of the soft pad and atraumatic robotic graspers. Great communication and teamwork among the surgeon at the robotic console, the table-side assistant managing the LAA delivering tool and the cardiac anaesthesiologist observing the LAA via transoesophageal echocardiography (TEE) are mandatory. Careful attention should be paid to avoid grasping other structures or tissue, including the circumflex artery, when deploying the clip. The clip is closed but remains within its delivery tool. Multiple TEE views are then conducted and reviewed, and the ST segments on the electrocardiogram and haemodynamic parameters are monitored before the clip is finally released. TEE aids the surgeon in checking the correct positioning of the clip before definitive closure. After final deployment, the delivery tool is removed, and the LAA is checked for haemostasis.
Outcome
The patient underwent reverse hybrid robotic assisted off-pump CABG (internal mammary artery to the left anterior descending), LAAO with a 40-mm Pro2 AtriClip and cryo nerve ablation of the left intercostals. The patient did not receive blood products intraoperatively and arrived in the intensive care unit extubated without pressors. Chest tubes were removed on postoperative day 2. The rest of the hospital stay was uneventful, and he was discharged home on postoperative day 3.
Discussion
In cardiac surgery, epicardial LAAO methods have demonstrated significant success rates, whereas internal techniques like purse-string suturing pose a greater risk of incomplete closure and residual blood flow [6]. Although the case was conducted using a robotic surgical system, this technique is performed the same way as in other forms of minimally invasive surgery, such as minithoracotomy or thoracoscopic approaches. The advantage is that robotic systems are less affected by body size and habitus compared to thoracoscopic systems.
TEE is crucial at every stage of the procedure. Prior to deployment, TEE ensures that there are no thrombi present in the LAA, because the presence of thrombus would contraindicate device deployment. The accurate positioning of the clip is confirmed through direct visualization, and complete closure of the LAA is verified using TEE echocardiography using color Doppler imaging. It is crucial that the device's axis aligns with the major axis of the LAA [7].
It has been previously demonstrated that the AtriClip not only prevents thrombosis but also achieves acute electrical isolation [8]. The choice of appropriate anticoagulation therapy after LAAO remains a complex issue. According to current guidelines for the management of AF [3, 4], patients typically continue to require lifelong therapeutic anticoagulation based on CHA2DS2‐VASc risk factors, regardless of LAA closure status. Comparative studies between epicardial LAA closure and OAC are lacking, so LAA closure cannot be viewed as a replacement for anticoagulation therapy. Currently, a strong indication for surgical LAA exclusion appears to be a contraindication for anticoagulation (Class of recommendation II B). Percutaneous LAAO can be a possible alternative, but not all patients are eligible due to anatomical characteristics, while surgical approaches (including robotic) do not suffer from this limitation.
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Conflicts Of Interest
Gianluca Torregrossa: Consulting fee from Peters Surgical
Authors
Massimo Baudo1, Amanda Yakobitis2, Courtney Murray2 & Gianluca Torregrossa1,2
Affiliations
1Department of Cardiac Surgery Research, Lankenau Institute for Medical Research, Main Line Health, Wynnewood, PA, USA
2Department of Cardiac Surgery, Lankenau Medical Center, Main Line Health, Wynnewood, PA, USA
Corresponding Author
Massimo Baudo
Department of Cardiac Surgery Research
Lankenau Institute for Medical Research
100 E Lancaster Avenue
Wynnewood
PA 19096
United States of America
Email: massimo.baudo@icloud.com
© The Author 2024. Published by MMCTS on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
