2.2 LAAC with ICE imaging
LAAC with ICE imaging was performed under local anesthesia without conscious sedation. Double right femoral vein access was obtained with an 11F 20-cm Terumo sheath (Terumo Europe, Leuven, Belgium) for introducing the 10F ICE catheter (Sound-Star, Biosense Webster, Diamond Bar, CA) and another 8.5F Swartz long sheath (SL1; AF Division, SJM, Minneapolis, MN). The geometry map of the left atrium (LA) including LAA was created by ICE probe manipulation at the right median atrial septum and at the coronary sinus ostium under CARTO3 three-dimensional mapping system (Biosense Webster, Inc). Shortly after successful ICE-guided transseptal puncture with a needle (BRK, SJM), a 6F pigtail catheter was advanced to the LAA to perform LAA angiography, with LA pressure≥12mmHg, at right anterior oblique and caudal projections. The angiographic diameters of LAA ostium and landing zone then were measured. After the pigtail catheter was removed, a guidewire was inserted through Swartz sheath to the left superior pulmonary vein (LSPV) under the ICE guidance. The Swartz sheath was further exchanged with a 10F delivery sheath to pre-dilate the transseptal puncture site. Then the delivery sheath was retracted into the inferior vena cava to allow the ICE catheter advance into LA through the same site which was tagged on the CARTO-Sound image guided by CARTO3 system without the need of any fluoroscopic guidance. The echocardiographic LAA ostium and landing zone diameters were measured using the “FLAVOR (F our L ong-A xisV iews a round Or ifice)” approach at 90°, 135°, 0° and 45° (Fig. 1 and 2). The 10F delivery sheath was advanced again to the LA over the guidewire placed in LSPV through the same transseptal puncture site with caution. The appropriate size of LAmbre device was selected based on both angiographic and echocardiographic measurements. Guided by fluoroscopy and ICE, the umbrella of the device was fully deployed at the landing zone by pushing the delivery cable, and the cover of the device was then deployed at the LAA ostium by unsheathing the delivery catheter. The position of the device and the degree of residual flow were assessed with ICE (Fig. 2). The device was released when the COST criteria (including Umbrella deployed beyondC ircumflex artery; Umbrella was fully O pen; Peri-device optimal S ealing (leak ≤ 3mm); Device stability confirmed by T ug test) were met and the cover of the device had no impingement on mitral valve and/or pulmonary vein ostium. Otherwise, recapture and/or resizing of the device would be attempted. Additional ICE assessment with ” FLAVOR ” approach would be performed after release of the device.
2.3 “FLAVOR” (F our L ong-A xis V iews around Or ifice) approach
The constructed LA geometry map at the antero-posterior projection was adjusted rightward and upward until LAA orifice was adequately exposed. The ICE probe was manipulated with caution to achieve the proposed 4 imaging planes (the angle between adjacent imaging planes was approximately 45°) for comprehensive evaluation of the LAA or device. Each plane was adjusted to show the long-axis view of LAA or the device. The ICE probe was initially advanced to the top of LA with slight posterior flexion to obtain the first view (similar to the TEE 90° view), which we defined as the 90° view. The second view (similar to the TEE 45° view) could be achieved through right and ante-flexion (R+A flex) of the ICE probe. The ICE probe was usually placed outside the left upper pulmonary vein ostium, and we defined as the 135° view. Next, the ICE probe was usually positioned between the left upper and lower pulmonary veins on the LA posterior wall to form the third view (similar to the TEE 0° view) by further rightward flexion (R flex), and we defined as the 0° view. Finally, the ICE catheter was rotated anticlockwise and advanced to mitral isthmus or across the mitral valve with posterior flexion to form the fourth view (similar to the TEE 135° view),which we defined as the 45° view. This systematic approach allowed comprehensive evaluation of LAA or devices mimicking TEE echo windows (Fig. 1 and 2).
2.4LAAC with TEE imaging
LAAC with TEE imaging also was performed under local anesthesia without conscious sedation. Transseptal puncture was performed with the 8.5F Swartz long sheath and transseptal puncture needle placed via right femoral venous access under fluoroscopic guidance. Then, a 6F pigtail catheter was inserted along the Swartz sheath for LAA angiography at the right anterior oblique and caudal projections. The sizes of the landing zone and the orifice were measured. The appropriate device size was selected according to the intraoperative angiographic and preoperative echocardiographic measurements and the device was implanted as aforementioned. Multi-planar TEE imaging (0º,45º,90º and 135º) under local laryngeal anesthesia with tetracaine were performed until no significant peri-device leak was detected by multi-projection cineangiography and the stability was confirmed by tag test. The device would only be released when COST criteria were met. TEE exams were performed by two experienced echocardiographers.