Fig. 6.1
Case 1: sizing of the LAA Watchman landing zone by angiography. The challenge in this particular case is that depth appears not to be sufficient at first glance. This measurement would suggest a 21 mm Watchman according to the sizing scheme, yet it might not be the largest diameter measured
Fig. 6.2
Case 1: sizing of the LAA ostium by 2D echo/X-plane. This particular LAA has the largest diameter measured in 45° suggesting a 24 mm Watchman device to be the device of choice
Fig. 6.3
Case 1: sizing of the LAA ostium by 3D echo employing Q-lab software for reconstruction; again a 24 mm Watchman device is recommended
Fig. 6.4
Case 1: 3D reconstruction of the LAA
Fig. 6.5
Case 1: tug test directly after release; Watchman has taken the typical configuration and unfolded completely. Note that the distal part is compressed to about 50% width compared to the proximal part
Fig. 6.6
Case 1: 24 mm Watchman device after release. Note that the depth measured underestimate the true landing zone
Fig. 6.7
Case 1: no leakage around device is detected. All release criteria (position, anchoring (tug test), size and sealing) are fulfilled
Fig. 6.8
Case 1: position assessment: a protrusion to the left atrium (“shoulder”) is observed. If this protrusion measures less than 50% of the diameter (Watchman 24 mm: 12 mm) in any of the four TEE views (0°, 45°, 90°, 135°), position can be accepted as the device still covers the LAA with PET fabric preventing thrombi from exiting the LAA
Fig. 6.9
Watchman device: the fabric covers 50% of the height of the device; a shoulder of around 12 mm can be accepted for a 24 mm device
Fig. 6.10
Case 1: final position as visualized by 3D echo (a) and angiography (b)
6.1.2 Dual Lobe LAA (Case 2)
Learning objective: standard technique if the anchoring lobe is limiting device expansion due to a proximal interlobar ridge.
A common challenge is to close a LAA with two lobes connected by a ridge that is protruding proximally. For successful closure of this anatomy the following strategy is recommended:
landing zone measurements find 23 mm to be the largest diameter, this time in 45° (Fig. 6.11)
probing of the LAA with the pigtail demonstrate two large lobes with a proximal ridge (Fig. 6.12)
the 27 mm Watchman is released from the superior lobe; if a first distal release doesn’t cover the inferior lobe the device must be positioned more proximal (Figs. 6.13 and 6.14)
only gaps <5 mm are allowed, measured at the smallest entry with colour flow next to the device (Fig. 6.14b)
3D imaging confirms successful closure of this particular LAA (Fig. 6.15)
Fig. 6.11
Case 2: closure of a dual lobe LAA. (a + b) Echo measurements of the Watchman landing zone in all four planes employing the X-plane mode. The largest diameter is measured at 23 mm resulting in a device size of 27 mm
Fig. 6.12
Case 2: closure of a dual lobe LAA. (a + c) pigtail in inferior lobe (position 1), (b + d) pigtail in superior lobe (position 2), the position to start Watchman release. In the RAO caudal angiographic projection the Watchman landing zone is measured to be 23 mm
Fig. 6.13
Case 2: default strategy to close a multi-lobe LAA with the Watchman device. The first release of a 27 mm Watchman (a, c) leaves an inferior gap since the proximal ridge between the lobes prevents the device from covering the inferior lobe. Note the very high compression of the distal part of the device in that small superior lobe (yellow arrow a and c, see Fig. 6.32a). Now the device is partially recaptured and released a few mm more proximal. This allows the proximal part of the same Watchman device as in a/c to expand completely and to cover the inferior lobe (b, d)
Fig. 6.14
Case 2: corresponding echo images to Fig. 6.33: The first release of a 27 mm Watchman (a, b) leaves a gap. The 27 mm device expands to only 20 mm; the explanation is found when looking at the angiographic images in 6.34: the interlobar ridge prevents the device to expand if released at this position. Now the device is partially recaptured and released a few mm more proximal. This allows the proximal part of this 27 mm Watchman device to expand completely and cover the inferior lobe (c, d)
Fig. 6.15
Case 2: corresponding 3D Echo images to the images in Fig. 6.33 and 6.34: (a) Visualization of the the proximal ridge between the lobes to cover. (b) The first release of a 27 mm Watchman is very deep into the LAA. (c) The more proximal final position with a small protrusion into the LA (shoulder) completely covers the entrance to the LAA
6.1.3 LAA with Inferior Take-off (Case 3)
Learning objective: a LAA with inferior direction requires specific measures to limit device protrusion into the left atrium.
If the LAA takes an inferior direction some challenges might occur to position the Watchman without a shoulder. The following technique is recommended:
measure landing zone both in angio and echo; be aware that the proximal marker of the sheath orients to where a 33 mm device might land outside the LAA (Fig. 6.15 a and b)
During release of the device from the distal LAA, a slight push is applied once 50% of the device is released. This enables the device to land exactly at the predefined landing zone (Fig. 6.16)
checking sealing and anchoring by the PASS criteria suggest the device to be successfully deployed (Fig. 6.17)
Fig. 6.16
Case 3: LAA morphology in an RAO caudal projection depicts an inferior take-off (a). Echo imaging does not provide information about the depth of the LAA but measures the Watchman landing zone also with 28 mm (b). “2-sizes up” leads to the decision of a 33 mm device w/o an issue of depth although the markers on the sheath suggest the device to protrude into the left atrium (a, orange dotted line). Release starts at the very distal end of the LAA (c). After release, the device shows its typical appearance(d)
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