case_images: PMC10810268_01
case_images: (A) Transoesophageal echocardiography (TEE) measurement of the maximum diameter of the left atrium appendage (LAA) orifice (25.0 mm); (B) baseline angiography; (C) the delivery sheath was placed in the anterior lobe, and the device was moved posteriorly; (D) in the TEE image, the extending device shoulder was represented by the white dot curve. TEE established the total length of device was calculated as 25.2 mm (white arrow dots), and the device's extension from the LAA ostium was measured at 16.9 mm (white arrow). Significant device protrusion of more than 50% from the LAA ostium was discovered along with a minor space (white asterisk) on the left side of device that did not meet the conventional device release criteria; (E) inadequate alignment between the delivery sheath (white arrow) and device (white arrow dots); video of the 'cobra twist' technique; (F) the delivery sheath was positioned using anticlockwise rotation (white arrow circle) and keeping the proximal device cobra-like head with forward pressure (white arrow); (G) the delivery sheath was then intentionally twisted clockwise (white circular arrow), which reduced the posterior device protrusion (white arrows); the process was deemed successful based on the results of (H) angiography and (I) TEE, which revealed that the device release criteria was <50% device protrusion from the LAA ostium [total device length: 25.5 mm (white arrow dots), protruded length: 12.0 mm (white arrow)] and no residual space in the left side of device (white asterisk).
case_images: ytae018f1.jpg
case_images: PMC10810268_01_ytae018f1.jpg
case_images: ytae018-F1
case_images: Considering the peri-procedural transoesophageal echocardiography findings (Figure 1A), a 31 mm WATCHMAN-FLX (Boston Scientific, Marlborough, MA) device was chosen for LAAC. Although the device was released from the anterior lobe of the LAA (Figure 1B and C), more than half of the device was protruding, especially in the posterior lobe (Figure 1D). The main cause of this phenomenon was considered to be the misalignment of the delivery sheath and device orientation axes (Figure 1E). This 'cobra twist' technique keeps the proximal WATCHMAN-FLX boll-like 'cobra' head in a manner that increases the working space (Figure 1F); thereafter, the delivery sheath axis was intentionally twisted clockwise at the timing of full device release (Figure 1G). After this manoeuvre, the WATCHMAN-FLX could be adequately aligned and implanted with acceptable device protrusion, including in the posterior lobe (Figure 1H and I).