Page 55 - BH-3-3

Brain & Heart A left atrial appendage occlusion review

Alternative methods of access have been employed for An additional sequela of LAA variability is the
various devices, including simultaneous endocardial and possibility of inadequate apposition of the occlusion
epicardial access; however, the vast majority of devices device, thus leading to PDL. PDLs represent an established
utilize a transseptal puncture and delivery technique. complication of both surgical and percutaneous LAAC
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Anatomic distinction is of extreme importance during device therapy, with a meta-analysis showing rates of any
the transseptal process as regions of the interatrial PDL between 15% and 55% on TEE imaging at the 45-day
septum, if crossed, can lead to puncture into extracardiac mark suggested by the PROTECT-AF protocol. The
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spaces, causing life-threatening complications. After the PROTECT-AF demonstrated rates of 40.9% and 13.3% for
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transseptal needle is introduced into the right atrium, a any PDL and leaks >3 mm, respectively, with the Watchman
short-axis view should be obtained on TEE as well as an device, and the Amulet-IDE trial had rates of 37.0% and
anteroposterior projection on fluoroscopy. 54-56 Various 11.2%, respectively, with the Amplatzer device. 48,61 This
techniques to perform the puncture exist, including the rate has been improved with newer models such as the
use of diathermy technology to induce an electric current Watchman FLX, which, per the PINNACLE-FLX trial, had
through the needle, employing electrocautery for enhanced a PDL rate of 17.4% at the 45-day mark. Of note, leaks
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precision during transseptal puncture. Once transseptal have been shown to change over time, especially depending
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puncture has been achieved, left atrial pressure tracing on their initial size, with one study demonstrating that
is confirmed before advancing the transseptal sheath, leaks <3 mm tended to regress over time, whereas leaks
followed by positioning of the device delivery system. 23,58 >3 mm tended to remain. Also of note, the method by
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9. Complications which post-procedural imaging is done may impact the
detection of leaks, with one study showing that patients
While percutaneous LAAC offers a minimally invasive who underwent Amplatzer device LAAO with both TEE
strategy for LAAC and thromboembolic protection, the and CT had significantly more PDL on CT imaging (61%)
procedure is not without risk of complications. These compared to corresponding TEE imaging (32%). 63
complications include perforation at the time of procedure, It remains unclear exactly what kind of clinical impact
cardiac tamponade, periprocedural stroke, and device
embolization. However, complication rates continue post-procedural PDLs have. The initial PROTECT-AF
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to decrease with newer iterations of devices. Pericardial trial data did not seem to show any decreased effectiveness
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effusion can notably arise in LAAC device placement for of the device or increased risk of stroke with a PDL.
several reasons. Catheter manipulation within the LAA can However, some studies have shown a correlation between
lead to injuries to the thin wall of the LAA. The anchoring even small leaks (<5 mm) on 45-day TEEs and increased
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struts and radial force from self-expanding cage devices can incidence of stroke/TIA and systemic embolization.
also lead to injuries to the LAA wall and extravasation of Other studies, including the NCDR LAAO Registry, have
blood into the pericardial space. The risk of effusions rapidly even shown an association between PDLs and increased
progressing to hemodynamic compromise and tamponade incidence of bleeding, possibly suggesting that the same
can be substantial, if not for the use of intraprocedural unknown risk factors that lead to PDLs lead to increased
TEE and/or ICE. Life-threatening pericardial effusion risk of bleeding. 63,64
and tamponade make the use of imaging during the The consensus remains that PDLs >5 mm
procedure of paramount importance to confirm the postprocedurally on follow-up TEE are considered a
presence of tamponade and to alert operators to the need failure of occlusion. In general, this condition, as indicated
for pericardiocentesis. The percutaneous delivery method by the PROTECT-AF trial, is treated with continued
for these devices also relies on placement of intravenous anticoagulation. However, alternative methods have been
sheaths; air emboli, particularly in large French sheaths, trialed in other studies, one of which was the release of
can rarely lead to embolic phenomena in the arterial system a spring coil into the LAA. In one study of patients with
through the transseptal passage. 59 at least moderate PDLs (>3 mm), placement of a spring

Device embolization is another complication of coil reduced leak size by a mean of 86.3% with complete
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percutaneous LAAC device placement. While rare, device occlusion in about 77% of patients. Radiofrequency
embolization is associated with a greater mortality rate. ablation has also been utilized with one study of patients
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Thought to occur due to device size mismatch to LAA size, with PDL >4 mm who underwent ablation showing either
pre-procedural imaging and planning becomes imperative complete occlusion or reduction to mild or very mild
to limit the potential of this complication. Operator PDL (1 – 2 mm) in 88.4% of patients. However, both of
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experience can be a confounding factor in procedural these were done in a small sample of patients, and further,
complications as well, as with any procedure. larger-scale trials are needed to establish these methods as

Volume 3 Issue 3 (2025) 7 doi: 10.36922/bh.4016