When Does LAA Clip Fail on TEE?
LAA clip closure fails on TEE when there is incomplete occlusion of the LAA orifice with peri-device leak (PDL) detected by color Doppler, device instability, thrombus formation on the device, or a residual stump greater than 10 mm. 1, 2
Defining Failure Criteria
Peri-Device Leak (PDL)
- Any PDL, regardless of size, is associated with higher thromboembolic complications compared to complete occlusion 1
- PDL is measured at its narrowest diameter (vena contracta) using color Doppler with a Nyquist limit of approximately 35 cm/s 1
- Recent evidence shows patients with PDLs have increased stroke risk, making even small leaks clinically significant 1
Residual Stump
- A residual LAA stump greater than 10 mm indicates unsuccessful closure 2
- Stumps create a thrombogenic surface that can lead to clot formation 2, 3
- Successful closure requires absence of LAA perfusion and no stump >10 mm 2
Device-Related Complications
- Device instability or erosion detected on follow-up TEE (typically at 45-90 days) indicates failure 1
- Device thrombus formation is associated with unfavorable outcomes and requires anticoagulation or additional intervention 1
- Malpositioning with perpendicular orientation to the LAA ostium rather than proper occlusive positioning 4
TEE Surveillance Protocol
Timing of Assessment
- TEE surveillance at 45-90 days post-procedure is advised to verify device stability, complete occlusion, and rule out thrombus 1
- Immediate post-deployment assessment during the procedure is critical to confirm proper positioning before device release 1, 5
Key TEE Views and Measurements
- Multiple imaging planes are required to fully assess the LAA and device position 1, 5
- Color Doppler interrogation is essential for detecting any residual flow around the device 1
- 3D TEE provides superior spatial orientation for assessing device positioning compared to 2D alone 6
Clinical Implications of Failure
Stroke Risk
- Patients with unsuccessful LAA closure have higher stroke rates: 7.4% versus 1.6% in those with successful closure 2
- The presence of thrombus in unsuccessfully closed LAA occurred in 41% of cases in one study 3
Management of Failed Closure
- Patients with detected PDLs may require either continuation/initiation of anticoagulation or undergo additional transcatheter closure procedures 1
- Reintervention decisions should be based on PDL size, patient stroke risk, and bleeding risk profile 1
Common Pitfalls
- Complex, multilobed LAA anatomy can lead to apparent proper positioning on fluoroscopy that is actually malpositioning on TEE 4
- Relying solely on fluoroscopy without TEE guidance increases risk of suboptimal deployment 4, 5
- Failure to perform adequate follow-up TEE at 45-90 days may miss late complications like device thrombus or delayed PDL development 1