Use of the LARIAT Suture Delivery Device to Prevent Strokes in Patients with Atrial Fibrillation
- Volume 14 - Issue 1 - January 2014
- Posted on: 12/19/13
- 0 Comments
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Arial fibrillation (AF) is the most common arrhythmia, afflicting approximately 3 million people in the United States, and has been associated with both dementia and stroke.1 Given the burden of AF in the United States, it is estimated that approximately 15% of cerebrovascular accidents arise from AF-associated thromboembolisms. Of anatomical structures in the heart, the left atrial appendage (LAA) is of particular interest, as upwards of 90% of thromboembolisms originate here.2 Recent data from the PROTECT AF study has demonstrated for the first time that exclusion of the LAA from circulation dramatically reduces the risk of thromboembolism.2 Currently, the LARIAT Suture Delivery Device (SentreHEART, Inc.) is the only FDA-approved, minimally invasive approach that can be used for occlusion of soft tissue, such as the left atrial appendage.3 In our institution, we limit this procedure to patients who are at high risk for stroke (CHADS2≥2) that are not candidates for anticoagulation due to comorbid illnesses (e.g., recurrent GIB). Here we present a recent case of LAA exclusion using the LARIAT Suture Delivery Device.
The patient was a 63-year-old man with a history of persistent atrial fibrillation and a CHADS2 score of 2, CHA2DS2-VASc risk score of 3, and a HAS-BLED risk score of 3, who had suffered from recurrent episodes of gross hematuria requiring transfusion. Given his high risk of stroke and intolerance to oral anticoagulants, he was referred for evaluation of LAA exclusion.
Description of Procedure
The day prior to the procedure, a transesophageal echocardiogram is performed to exclude LAA thrombus. The procedure itself is performed under general anesthesia. We place a 5 Fr radial arterial line for real-time blood pressure monitoring prior to venous or epicardial access. Once the patient is anesthetized, a TEE probe is passed to guide transseptal catheterization and deployment of the LARIAT. A 6 Fr venous sheath is placed in the left femoral vein to facilitate administration of vasoactive agents and blood products if necessary. An 8 Fr short sheath is placed in the right femoral vein to allow for a right ventriculogram as well as transseptal catheterization.
Deployment of the LARIAT device is critically dependent upon correct epicardial access. Specifically, anterior epicardial access aligned with the superior-inferior axis of the LAA is required for proper tracking of the LARIAT. In order to facilitate correct epicardial access, superior-inferior orientation is performed in the AP configuration. Typically this is between 1230 and 230 on a clock face. The exact trajectory is based upon preprocedure 3D CT reconstruction of the LAA (Figures 1A-D). A skin nick is made 2 cm below the xiphoid process. We then perform a right ventriculogram in a straight left lateral to ensure that we have an approach that allows for anterior access to the epicardial space. In the AP orientation, the micropuncture needle is advanced under the rib cage along the superior-inferior trajectory (Figure 2A). Once the needle is under the rib cage, fluoroscopy is performed in a left lateral orientation. As the pericardium is approached, a small amount of contrast is given to visualize tenting of the pericardium (Figure 2B). Once the pericardial space is accessed, contrast will flow freely around the heart silhouette. While a Tuohy needle may also be used for epicardial access, we have found less inadvertent RV puncture with the micropuncture approach. After entering the pericardial space, the micropuncture wire is advanced. It is important that the wire crosses the midline, ensuring that the needle is not in the RV (Figure 2C). Should inadvertent RV puncture occur, the needle is withdrawn slightly and redirected. Once the wire is confirmed to be in the pericardial space, the micropuncture dilator is advanced and a more supportive wire such as an 0.035” 180 cm wire is exchanged for the micropuncture wire. Following serial dilation with a series of dilators, a 13 Fr soft tip sheath is placed in the epicardial space, through which the LARIAT device will be deployed (Figure 2D). During the passage of dilators and sheaths, we monitor for evidence of RV compression and effusion using TEE. While uncommon, injury to the venous structures in the heart may cause significant bleeding.
Once epicardial access is complete, the patient is administered heparin and placed on a heparin drip to maintain ACTs between 300-350. The short femoral venous sheath is exchanged for an 8.5 Fr SL-1, and using a combination of manometry, fluoroscopy and echocardiography guidance, transseptal catheterization is performed. Once in the left atrium, the SL-1 sheath is angled toward the LAA, and contrast is injected to image the appendage in both RAO and LAO caudal orientations (Figures 3A and B).
Deployment of the LARIAT
The LARIAT is guided over the appendage by following a rail created by attaching two wires with rare-earth magnets. The first wire and magnet (endowire) is placed in the appendage via the SL-1 sheath, while the second wire and magnet (epiwire) is delivered via the soft tip epicardial sheath (Figures 4A-F). Once the magnets are connected, the LARIAT Suture Delivery Device is advanced into the epicardium. We prefer to perform this in the LAO orientation to ensure that the LARIAT passes over the anterior and posterior lobes of the appendage, before going to an RAO caudal orientation to watch the LARIAT advance to the neck of the appendage. At this point, an occlusion balloon is passed over the endowire and inflated at the ostium of the LAA. Position within the appendage is confirmed echocardiographically. The fluoroscopic markers on the balloon can then be used to ensure that the LARIAT has been fully advanced to the ostium. The LARIAT is then tightened to approximate the LAA tissue. If fluoroscopy and echocardiography confirm that the appendage has been successfully excluded, the endowire and balloon are withdrawn from the appendage and the suture is deployed (Figures 4A-F). TEE and fluoroscopy images are then obtained (Figures 5 and 6).
After five minutes, the suture is tightened again. The suture is clipped, and the sheath is removed from the pericardial space. An 8 Fr pigtail drain is left in the pericardial space overnight. The SL-1 sheath is then removed from the left atrium.
Our patient did well overnight and was discharged the following morning with a two-week course of colchicine and NSAIDs. At one-month follow-up, a TEE was repeated, which demonstrated that the LAA appendage remains excluded from circulation.
The LARIAT Suture Delivery Device is a safe, effective and minimally invasive approach to excluding the LAA from circulation, presumably reducing the risk of thromboembolic stroke from atrial fibrillation. However, long-term studies are lacking and the risk of pericardial access/transseptal puncture needs to be weighed against the risk of stroke.4,5 Serious complications associated with the LARIAT procedure, including appendage perforation, RV puncture/laceration, laceration of the left internal mammary artery/epigastric arteries, and damage to abdominal organs, are uncommon but devastating when they occur.3,4,6 In addition, there is a learning curve to performing this procedure safely. Despite the limitations enumerated above, the LARIAT system offers the best alternative to patients who are at high risk of stroke but who cannot tolerate an oral anticoagulant.
Disclosures: The authors have no conflicts of interest to report regarding the content herein.