The Lariat system (SentreHEART, Palo Alto, CA, USA) targets a different approach to LAAO. This device allows for percutaneous suture ligation of LAA via a snare that cinches the LAA from the pericardial space via a combination of trans-septal and epicardial access (Figure 1).[32,33] Patients with prior cardiothoracic surgery are not candidates for LAAO by the Lariat system. Left atrial appendage occlusion by the Lariat system may be difficult in patients with superiorly oriented LAA or in LAAs that course behind the pulmonary artery. One striking benefit of the Lariat system compared with the previously mentioned LAAO devices is that with the Lariat system, no device is left behind in the LAA after the procedure, theoretically circumventing the need for periprocedural anticoagulation. The Lariat system received FDA 510(k) clearance for use in approximation of soft tissues, which does not require clinical testing of the device for the specific indication under consideration but instead cleared based on demonstration of substantial equivalence with existing devices.[35,36] The existing devices that were mentioned for this special clearance included Ethicon Endosuture System™ and HysteRx Liga-Loop Suture Applicator™, which are preformed sutures used for approximation of tissues during laparoscopic surgery and vein harvesting.[37,38] The use of the Lariat system for LAAO is off-label in the USA. It received CE mark in 2009.
The safety and efficacy of this procedure for LAAO have been explored in several observational studies (Table 3). In a single-centre observational study, Bartus et al. reported technical success rate of 96% among 89 patients that underwent Lariat procedure for LAAO. However, rate of serious adverse events was 11.2% (n = 10). Perioperative events included events related to epicardial access (right ventricular puncture and superficial epigastric artery laceration) and trans-septal access (haemopericardium). Post-operative major adverse events included severe pericarditis (n = 2), late pericardial effusion (n = 1), unexplained sudden death (n = 2), and late strokes (n = 2). Similarly, in a multi-centre observational study by Price et al. initial technical success rate among the 154 subjects was 94% while procedural success (defined to be without procedural complication) was lower at 86%. Pericardial effusion occurred in 10.5% and major bleeds in 9.1%. In a systematic review of five reports of Lariat device use in 309 separate subjects, Chatterjee et al. reported overall success rate of 90.3%, while 2.3% required urgent cardiac surgery (n = 7). Query of the FDA Manufacturer and User Facility Device Experience (MAUDE) database revealed 35 unique reports of adverse events with the Lariat device, 5 of which reported pericardial tamponade and death, and an additional 23 reported need for urgent cardiac surgery. The FDA subsequently issued a safety communication in 13 July 2015, reporting patient deaths and other serious medical complications including cardiac laceration and/or perforation, complete LAA detachment from the heart, cardiac tamponade, and cases involving need for urgent cardiac surgery. Notwithstanding, a more recent large multicentre registry (n = 712) by Lakkireddy et al. reported improvement in procedural success rate (>95%) and procedure-related mortality (n = 1, 0.14%) and cardiac perforation requiring open heart surgery (n = 10, 1.44%). The authors attributed their successes to several factors, including operator experience, as well as refined technology using a small bore micropuncture needle (vs. previously employed large bore Pajunk Needle) for epicardial access and introduction of periprocedural colchicine use to minimize pericardial and pleural inflammation. Furthermore, the study included patients with history of prohibitive bleeding on OAC (67.4%) and fall risk (11.6%) in which OAC was discontinued prior to LAAO. The remaining 21% were kept on OAC for 6 weeks, but all were taken off OAC unless a thrombus was noted on the follow-up TEE (n = 12). Instead of OAC, patients were maintained on single oral antiplatelet agent (80%), with or without 6 weeks of initial DAPT (20%). Moreover, epicardial LAAO and not its endocardial counterparts results in electrical isolation of the LAA which seems to reduce AF recurrence. Currently, a prospective RCT is under way to evaluate the efficacy of concurrent LAAO with the Lariat system and pulmonary vein isolation (PVI) compared with PVI alone in maintaining sinus rhythm in patients with persistent or long-standing AF (ClinicalTrials.gov, NCT02513797). The study is powered to evaluate recurrent AF risk as the primary endpoint, but will evaluate differential stroke risk as a secondary endpoint.
Europace. 2018;20(9):1412-1419. © 2018 Oxford University Press
Copyright 2007 European Heart Rhythm Association of the European Society of Cardiology (ESC). Published by Oxford University Press. All rights reserved.