Leaks After LAA Closure: Incidence, Clinical Implications, and Management

For many years, oral anticoagulation (OAC) has been the only therapeutic alternative for stroke prevention in patients with atrial fibrillation, with all the limitations related to its management, the poor adherence to therapy, and the potential interactions with food and drugs. In fact, approximately 30-40% of patients with an indication to OAC are not adequately anticoagulated mainly due to contraindications, poor adherence to therapy, and/or the presence of coexistent comorbidities/risk factors associated with a higher risk of bleeding (e.g., renal failure, liver disease, and age).

Over the last decade, percutaneous and hybrid techniques to exclude the left atrial appendage (LAA) from systemic circulation have steadily gained interest as viable alternatives to OAC in patients with contraindications to long-term anticoagulation.1 In the recent clinical trial PRAGUE-17 (Left Atrial Appendage Closure vs. Novel Anticoagulation Agents in Atrial Fibrillation) comparing percutaneous LAA occlusion with direct OAC, no differences were observed in terms of stroke/transient ischemic attack prevention, clinically significant bleeding, or cardiovascular death between the two therapeutic strategies.2

In addition to a risk of thrombus formation for endocardial devices, incomplete appendage exclusion is a drawback shared by any closure technique (percutaneous, hybrid, or surgical) targeting the LAA.

The incidence of leaks widely varies based on the follow-up imaging modality, the cut-off used to discriminate clinically significant from nonsignificant leaks, and the technique used to close the appendage.3 If and when incomplete LAA closure carries a significant residual risk of thromboembolic (TE) events are still matters of debate. Previous studies observed a higher incidence of TE events in patients with incomplete surgical and hybrid ligation.4,5 This risk appears to be unrelated to conventional risk stratification models and, notably, has been reported to be higher in the presence of leaks of smaller size (<5 mm). However, this association has not been confirmed in patients with incomplete percutaneous LAA occlusion.6

Nonetheless, OAC is frequently continued in patients with incomplete percutaneous LAA closure if leaks >5 mm are present. This strategy may be potentially detrimental due to a concomitant high risk of bleeding events. As such, other interventional strategies have recently been developed to obviate the potential residual risk of TE linked to a suboptimal appendage closure procedure. Specifically, plug-type devices and embolization coils (Figure 1) have been used to target residual leaks resulting from percutaneous, hybrid, and surgical procedures.7–9

Figure 1: Examples of Three Different Percutaneous Techniques for LAA Leak Closure

Figure 1
(A) LAA coiling after WATCHMAN (Boston Scientific; Marlborough, MA) implantation versus (B) implantation of a septal occluder after incomplete LAA ligation with a LARIAT device (SentreHEART, Inc.; Palo Alto, CA) or (C) to close an uncovered lobe after WATCHMAN implantation. We recently reported the first experience of transcatheter leak closure with embolization coils.7

The study is a preliminary report of the prospective, interventional TREASURE (Transcatheter Leak Closure With Detachable Coils Following Incomplete Left Atrial Appendage Closure Procedures) registry (NCT03503253).10 We enrolled 30 patients showing evidence of a significant residual leak following LAA closure procedures. Of them, 25 patients had received a WATCHMAN device (Figure 1A), 2 received an Amplatzer Amulet device (Abbott; Abbott Park, IL), and 3 had undergone appendage ligation with a LARIAT suture delivery device. In addition to the size of the residual appendage patency, patients were included based on their TE and bleeding risk (CHA2DS2-VASc ≥ 3 and HAS-BLED ≥ 3) in combination with one of the following:

  1. Recent history of significant bleeding events or predisposition to bleeding (e.g., recurrent falls)
  2. Current indication for long-term dual antiplatelet therapy
  3. History of TE events after LAA occlusion upon exclusion of other potential causes (e.g., carotid disease)

Of note, 66.7% (n = 20) of patients had a leak size <5 mm; these patients were included on the basis of an individualized risk stratification strategy that included other clinical characteristics (e.g., post-LAA occlusion TE) and anatomical characteristics (e.g., leak features, LAA trabeculation, post-occlusion thrombus formation and size within the LAA, and left atrial dense spontaneous echo contrast).11,12 Procedural duration was 76 ± 41 min with a mean fluoroscopy time and injected contrast medium volume of 21 ± 14 min and 80 ± 47 mL, respectively. The average number of coils deployed within the LAA was 3 per patient (interquartile range: 2-4). A wide selection of diameter, length, and shape options is available for coils. Our strategy of choice was to start with one or more larger coils in order to achieve a better volume effect within the LAA and then refine the closure by using smaller coils.

Follow-up transoesophageal echocardiogram confirmed complete LAA closure or a minimal residual leak in 25 (83.3%) patients. A repeat procedure was performed in 3 of the 5 patients who still had a moderate leak, which resulted in complete closure or a significant reduction of the leak size in all of them. LAA coiling led to a 92.7% reduction in leak size, resulting in a success rate of 93.3%. OAC was subsequently interrupted in all 28 patients upon verification of complete exclusion of the LAA from systemic circulation. Of the 33 procedures, 1 (3.0%) was complicated by a pericardial tamponade requiring a pericardial window and 1 (3.0%) by a pericardial effusion.

When planning a leak closure procedure, there are some anatomical features that help drive our choice for a certain approach. Because LAA coiling requires a physical boundary to prevent coil displacement, this technique might be suboptimal in presence of completely uncovered LAA lobes or large leaks resulting from LARIAT or surgical ligation. In these cases, plug-type devices should be preferred (Figure 1B-C). Contrariwise, circular-shaped occluders should be avoided in case of a crescent-shaped leak resulting from endocardial device implantation for two main reasons. First, these leaks form between the edge of the device and the rim of the appendage; therefore, a plug-type device, with its circular shape, may be unsuitable to fill the crescent shape of the leak. Second, the landing zone might be too shallow to allow an adequate deployment of the distal disc of the plug within the appendage.

In conclusion, LAA coiling appears to be a new valuable tool to optimize LAA occlusion in those patients with a significant residual leak and high TE and bleeding risk. More safety and efficacy data from the TREASURE registry will be available soon. Meanwhile, further efforts should be made to better understand the mechanisms of leak formation and their potential clinical implications for the risk of TE events.


  1. Della Rocca DG, Del Prete A, Di Biase L, et al. Current Endocardial Approaches for Left Atrial Appendage Closure. Eur J Arrhythm Electrophysiol 2019;5:40-6.
  2. Osmancik P, Herman D, Neuzil P, et al. Left Atrial Appendage Closure Versus Direct Oral Anticoagulants in High-Risk Patients With Atrial Fibrillation. J Am Coll Cardiol 2020;75:3122-35.
  3. Sahore A, Della Rocca DG, Anannab A, et al. Clinical Implications and Management Strategies for Left Atrial Appendage Leaks. Card Electrophysiol Clin 2020;12:89-96.
  4. Aryana A, Singh SK, Singh SM, et al. Association between incomplete surgical ligation of left atrial appendage and stroke and systemic embolization. Heart Rhythm 2015;12:1431-7.
  5. Mohanty S, Gianni C, Trivedi C, et al. Risk of thromboembolic events after percutaneous left atrial appendage ligation in patients with atrial fibrillation: Long-term results of a multicenter study. Heart Rhythm 2020;17:175-81.
  6. Viles-Gonzalez JF, Kar S, Douglas P, et al. The clinical impact of incomplete left atrial appendage closure with the Watchman Device in patients with atrial fibrillation: a PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) substudy. J Am Coll Cardiol 2012;59:923-9.
  7. Della Rocca DG, Horton RP, Di Biase L, et al. First Experience of Transcatheter Leak Occlusion With Detachable Coils Following Left Atrial Appendage Closure. JACC Cardiovasc Interv 2020;13:306-19.
  8. Pillai AM, Kanmanthareddy A, Earnest M, et al. Initial experience with post Lariat left atrial appendage leak closure with Amplatzer septal occluder device and repeat Lariat application. Heart Rhythm 2014;11:1877-83.
  9. Alkhouli M, Alqahtani F, Kazienko B, Olgers K, Sengupta PP. Percutaneous Closure of Peridevice Leak After Left Atrial Appendage Occlusion. JACC Cardiovasc Interv 2018;11:e83-e85.
  10. Transcatheter Leak Closure With Detachable Coils Following Incomplete Left Atrial Appendage Closure Procedures (TREASURE) (ClinicalTrials.gov website). March 14, 2019. Available at https://clinicaltrials.gov/ct2/show/NCT03503253. Accessed July 27, 2020.
  11. Gedikli Ö, Mohanty S, Trivedi C, et al. Impact of dense "smoke" detected on transesophageal echocardiography on stroke risk in patients with atrial fibrillation undergoing catheter ablation. Heart Rhythm 2019;16:351-7.
  12. Ayhan H, Mohanty S, Gedikli Ö, et al. A simple method to detect leaks after left atrial appendage occlusion with Watchman. J Cardiovasc Electrophysiol 2020;Jun 29:[Epub ahead of print].

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Pericardial Disease, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Arrhythmias, Cardiac, Ischemic Attack, Transient, Atrial Fibrillation, Atrial Appendage, Septal Occluder Device, Platelet Aggregation Inhibitors, Anticoagulants, Risk Factors, Incidence, Cardiac Tamponade, Pericardial Effusion, Pharmaceutical Preparations, Prospective Studies, Follow-Up Studies, Thromboembolism

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