discussion
To our knowledge,it has rarely been
reported that a planted LAmbre device
gets dislocated during the procedure
of Left Atrial Appendage Occlusion before and the procure was meeting
COST criteria.A LAmbre device (Lifetech Scientific Corp., Shenzhen,
China)is one of the “anchor and seal”devices and it consists of an
umbrella and a cover connected by a short central
waist1.The distal umbrella comprises 8 claws with
individual stabilizing hooks attaching to them to facilitate anchoring
to LAA wall1.Once some of the hooks fail to anchor to
the LAA wall steadily,the occluder may become mobilizable in horizontal
direction while the tug test proves it is stable in the vertical
direction.In this situation,the device could detach from the landing
position once losing the traction from the delivery sheath and that may
account for the present case.The size of the LAmbre device should be 4-6
mm larger than the measured LAA orifice, specifically based on the
structure of the LAA and the compression degree of the implant. The
choice of a 34-38mm LAmbre device was reasonable in this case but this
patient’s LAA was in a chicken-wing shape and the landing disc was not
deployed coaxially with the LAA.Both of the umbrella and the cover are
circular, the eccentricity and irregularity of the LAA orifice have been
verified implicated in residual leak2 and they may
have potential influence on the stability of the device. To ensure the
device solid,we should confirm the following points to make sure the
occluder is in the optimal position
before releasing it completely:the umbrella is rectangular or inverted
trapezoid, the 8 mark points are located in the same horizontal plane
with the center point,the upper edge is smooth and fixed, and the cover
is in the shape of concave.
Watchman device differs from LAmbre in structure and it is a
self-expanding nitinol framed structure with fixation barbs and a
permeable polyester fabric to cover the orifice of the
LAA3.Watchman device has limitations like limited
recapture and repositioning capabilities3.Li et
al4.reported a case of successful percutaneous
retrieval of a detached watchman device by clipping device hub via a
12-F transseptal sheath after two failed attempts.One of the advantages
of the LAmbre device is that it can be deliberately recaptured,
completely retrieved and redeployed.Qiu et al .and Sanhoury et
al.reported two cases of successful retrieval of LAmbre device with the
devices respectively located in the aortic arch and the abdominal
aorta.Both of their patients were asymptomatic during the
procedure.Unfortunately,the the device was trapped in our patient’s
mitral valve and caused hemodynamic changes rapidly.We immediately put
the patient on life support and tried percutaneous recapture but that
didn’t work .The device was subsequently removed by a cardiovascular
surgery.As Wang et al.reported,the occluder can hardly be retrieved
through a percutaneous sheath and usually lead to device-related injury
when it is trapped in left ventricle(LV)5.As far as we
know,a successful percutaneous
recapture of a LAmbre device trapped in the mitral valve has never been
reported till now.For the LAmbre device,when we rotate the sheath
counterclockwise repeatedly,the unloading of the occluder may occur.To
avoid this situation,we must keep an eye on the occluder and operate
prudently especially when we rotate the sheath with the occluder in the
state of half release. If the device unexpectedly falls in the LA or the
aorta and the patient’s hemodynamic parameters are stable,we can still
attempt to retrieve the device by using forceps or snares through a
adjustable curved sheath.A catheter should be used to fix the implant
via femoral access and then we need to advance a pigtail to the mitral
valve orifice through the septum to prevent the occluder from falling
into the LV further.During this procedure, ACT should be frequently
tested to avoid thrombosis.If the
device locates in the mitral valve or LV and causes hemodynamic
changes,percutaneous retrieval can
hardly work and a surgery should be performed as quickly as possible to
retrieve the implant.
Kang-zheng YUAN and Jian WANG contributed equally to this work.