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Brain & Heart A left atrial appendage occlusion review

multi-planar reconstruction also offers similar advantages Table 3. Comparison of TEE versus ICE for LAAC
as CCT and has been often used to overcome the 2D TEE
limitations in current practice, though it would require the TEE ICE
TEE echocardiographer to have specialized training in 3D Advantages • Familiarity • Reduces the need for an
anesthesiologist
TEE. Comparison data of real-time 3D TEE with real-time • 3D evaluation • Familiar imaging for most
• High‑resolution
multi-planar reconstruction and CCT is limited. imaging electrophysiologists
• Easily available • Shorter in‑room time
6.2. Cardiac magnetic resonance imaging • Low cost • Faster turnaround time
Cardiac magnetic resonance imaging (CMR) is an • Conscious sedation
alternative to CT, which provides static and dynamic Disadvantages • Risks of general • Requires additional venous
access
anesthesia
assessments of cardiac function. Its benefit lies in its ability • Imaging • Mandatory left atrium
to assess structural aspects of the heart, such as the degree quality is often positioning for good quality
of fibrosis, anatomical variations of the LAA, sizing of the operator-dependent • Higher cost
LAA, and the presence or absence of thrombi within the • Risks of TEE • Limited operator experience
4
LAA. Although studies have demonstrated in small study • Gastro‑esophageal
contraindications
populations that pre-procedural assessment with CMR
led to successful implantation without complications, it Abbreviations: ICE: Intracardiac echo; LAAC: Left atrial appendage
closure; TEE: Transesophageal echo imaging.
is known that CMR is a costly procedure and not widely
available in many centers across the United States. For anticoagulation therapy, this can be prohibitive in the elderly
4
these reasons, pre-procedural assessment with TEE has and patients who are predisposed to significant bleeding.
generally been favored as the imaging modality of choice. For these patients, there is a class IIb recommendation for
6.3. ICE-guided LAAO surgical or percutaneous LAAC, both of which provide an
alternative to pharmacologic anticoagulation. 41
Intracardiac echo (ICE) represents an increasingly used
alternative to TEE for intraprocedural imaging, mainly 7.1. Surgical LAAC
because of increased efficiency and the fact that it only Surgical closure of the LAA has predominantly been
requires conscious sedation – unlike anesthesia required for performed during concurrent open-heart cardiac
TEE guidance. Access for the ICE probe is obtained from procedures such as coronary artery bypass graft surgery
the femoral vein, where the probe is advanced directly to the or surgical valve repair procedures. Although surgical
41
target structures in the heart. While 2D ICE provides only closure in theory would allow for direct visualization
single-plane imaging and generates lower far-field imaging of the LAA and allow for complete closure, the LAAO
resolution, the introduction of 3D-ICE further expands its Study revealed that appendages closed with staples led to
usage and capabilities for LAAO imaging, as the imaging complete occlusion in up to 72% of cases, whereas sutures
plane can be rotated, similar to TEE, to fully visualize target resulted in complete closure rates as low as 45%. This
42
structures, including the LAA. This rotation capability suggests a persistent risk of thromboembolic events with
35
allows for in-depth assessment of the LAA and any implanted surgical LAAC. Subsequent studies have also suggested an
devices without the need for aggressive probe manipulation association between incomplete closures in surgical LAAC
within the left atrium, right ventricle, or pulmonary arteries. with thromboembolic events. As surgical LAAC is done
4,41
A previous expert consensus source details how to obtain during concomitant surgical procedures, data are lacking on
optimal ICE views of the LAA. Unfortunately, cost stands isolated surgical LAAC and short- and long-term outcomes.
36
as the limiting factor for ICE probes.
7.2. Percutaneous LAAC
For placement of LAAO devices, ICE appears to be non-
inferior to TEE in terms of procedural success, periprocedural Percutaneous LAAC devices were introduced for the same
purpose of thromboembolic protection through isolation
complications, and long-term outcomes in several single and of LAA, but from a minimally invasive route. These devices
multicenter studies. 37-40 The advantages and disadvantages of are delivered through catheter-based techniques. A
43
TEE and ICE are summarized in Table 3. number of devices have been introduced, as below, with
7. Mechanisms of LAAC therapy: Surgery unique design specifications, offering various advantages.
versus percutaneous strategies 7.2.1. PLAATO (Appriva Medical, Sunnyvale, CA)

Although the diagnosis of atrial fibrillation usually The percutaneous LAA transcatheter occlusion device was
entails subsequent thromboembolic protection with the first device introduced of its kind, designed to offer

Volume 3 Issue 3 (2025) 5 doi: 10.36922/bh.4016