Left Atrial Appendage Exclusion Utilizing the LARIAT Device: Tips, Tricks, and Pitfalls in a Community Hospital Setting

Embolic stroke is one of the most severe consequences of atrial fibrillation, and the risk of stroke is mitigated by oral anticoagulation therapy. Unfortunately, anticoagulation is often poorly tolerated and the risk of devastating bleeding events over many years on therapy is not insignificant. Most thrombi are thought to form in the appendage portion of the left atrium in atrial fibrillation. Here we discuss transcatheter left atrial appendage exclusion using the LARIAT Suture Delivery Device (SentreHEART, Inc.) in a community hospital setting. 

Transcatheter left atrial appendage exclusion procedures are complex; a coordinated multidisciplinary approach is essential to their success and in managing potential complications. Indispensable members of the team include echocardiography imaging specialists comfortable with transcatheter procedures, anesthesiologists comfortable with cardiac patients, cardiothoracic surgeons available for prompt backup, and catheterization/EP staff comfortable with managing potentially acutely ill patients. Additionally, there are many advantages to having a strongly coordinated program between electrophysiology and a structural heart disease physician. Frequent success is the expectation with these cases, and when achieved, these procedures are elegant. Preparedness is the key to dealing with the occasional serious complication. For a coordinated response to these rare adverse events, the team should have an understanding of the procedure, the steps involved, and the potential complications along the way.

Procedure: Our Approach

A cardiac CT specifically analyzing the left atrial appendage and its maximal diameter (<40 mm) is performed in all potential patients. Patients scheduled for appendage exclusion with the LARIAT device are started on colchicine 0.3 mg twice a day, five days before the procedure, with the goal of minimizing post-operative pericarditis, which has been reported following appendage ligation. On the day of the procedure, anesthesia inserts an arterial monitoring catheter as well as a central venous catheter prior to induction, intubation, and general anesthesia. Next, our echocardiography colleagues perform a baseline transesophageal study to rule out clot in the appendage, confirming appropriate appendage size (Figure 1) and gaining an understanding of the individual patient’s anatomy as will be relevant for the case.

Our first procedural step is to place a Kelly clamp one to two finger breadths below the subxiphoid process, and then under fluoroscopy, we tape a dilator from the tip of the Kelly in the presumed direction of the appendage (Figure 2A). After central venous access in the right femoral vein is achieved, a pigtail catheter is placed in the right ventricle and a ventriculogram is performed in the left lateral position, being sure to visualize the tip of the Kellys (Figure 2B). If gastric air bubbles are noted between the heart and the Kellys in both the lateral and AP views, a naso-gastric (NG) tube is passed into the stomach and placed on low wall suction prior to proceeding. We then make a skin laceration at the site of subxiphoid entry and spread this tissue adequately to accommodate a 13F sheath. For pericardial access, we use a micropuncture needle and, more recently, we have incorporated a 18G 3.5 cm spinal needle through which the micropuncture needle is introduced. This has provided added stability and tactile feel to the process. The short spinal needle is positioned in the direction of the dilator with the camera in the lateral position just under the sternum/rib, but well away from the heart (Figure 2C). The micropuncture needle is then advanced in the lateral position and in line with the dilator taped to the skin into the pericardial space, confirming this position with 50/50 contrast and with micropuncture wire passage across the patient midline and contained within the pericardial space. Liberal use of cine fluoroscopy can be valuable as the micro-needle approaches the pericardium for adequate visualization. Once the micropuncture sheath has been inserted and the wire has been exchanged for a 0.035” wire, we progressively dilate the tract with serial dilators. Prior to inserting the SentreHEART 13F pericardial sheath, we place a 8F 35 mm length Cordis BRITE TIP sheath into the pericardial space and place a second “backup” wire into the pericardial space (Figure 2D). This wire serves a role in the case of a sudden effusion related to bleeding. As a general rule, when the appendage is well visualized on TEE, the position of the appendage will be at the level of the TEE probe in the LAO position (Figure 2D). 

Next, a transseptal puncture is performed under biplane echocardiographic guidance with the ideal position being posterior and inferior in the fossa ovalis (Figure 3). The SL1 catheter is then positioned at the os of the appendage, and an angiogram of the appendage is performed in the LAO and RAO projections. The RAO view elongates the appendage and LAO view provides confirmation of the anterior or posterior direction of the appendage and catheters/wires. The endocardial balloon catheter with magnetized wire is then positioned in the appendage, and the wire is advanced to the anterior lobe of the appendage under fluoroscopic, angioscopic, and echocardiographic guidance. The epicardial wire is then advanced through the pericardial sheath and the magnets are connected, usually in the RAO camera position. Of critical importance in these cases is the position of the epicardial and endocardial catheter/wire. The desired position is viewed in the LAO position (Figures 4A and 4B). If the catheters are well aligned (Figure 4A), the remaining portions of the case are simplified. When the catheters/wires are misaligned (Figure 4B), there can be significant challenges in connecting the wires and advancing the LARIAT device over the appendage. One potential solution to when the catheters are misaligned is to advance the epicardial magnet into the pericardial space without connecting to the endocardial magnet. The LARIAT is then advanced over the endocardial wire and opened in the pericardial space (Figure 2C). The pericardial catheter is then rotated so the magnets align and connect. Another significant pitfall or caution in these cases is to never advance the pericardial sheath after the dilator and 0.035” wire have been removed, as this can lead to right ventricular tearing or puncture. Rotation is acceptable but not ideal; forward or backward motion is dangerous. 

Finally, the magnets are aligned and connected and the LARIAT is advanced over the epicardial wire and opened in the pericardial space. Before advancing the LARIAT outside the 14F sheath, be sure to pull back the second pericardial “backup” wire to the tip of the pericardial sheath, so the LARIAT opening is not affected by this wire. Once the LARIAT is opened in the pericardial space, the opaque marker on the LARIAT lasso should be on the left side in the RAO position (Figure 3). The LARIAT is advanced over the appendage under fluoroscopic guidance. The magnets should not disconnect during this step, and the motion for advancing the device should be a gentle rocking as opposed to a forceful movement (resistance is bad). To guide the proper positioning of the LARIAT lasso over the base of the appendage, the balloon at the tip of the endocardial catheter, which can be visualized by echo and angiography, can be a useful guide. After synching down, the LARIAT echocardiography and angiography can demonstrate the depth of appendage exclusion; a channel between the atrium and the appendage may still be present before fully tightening the suture. We have adopted the concept that a residual channel of ≤3 mm at the end of the case is an acceptable closure. Once the suture has been ligated and echo confirms no new effusion, the 14F pericardial sheath is replaced for a 8F pigtail drain. 

With regards to post-procedure management, we generally have extubated out patients in the lab at the end of the case. We leave the pericardial drain in place for a minimum of six to eight hours, and if there is minimal non-bloody drainage over that time (<50 cc), the pigtail is removed. We increase the colchicine dose to 0.6 mg bid following the procedure, and use ketorolac for initial pain control followed by p.o. NSAIDs and acetaminophen. Our patients have generally been discharged on postprocedure day #2. After one month, we perform a follow-up TEE to assess the adequacy of closure; if there are no additional clinical, echo, or EKG findings to suggest pericarditis, we stop colchicine at this time. 

Disclosure: The authors have no conflicts of interest to report relative to the content of this article.