There are very few cases of cardiac occluder detachment, and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment. This case innovatively used ultrasound guidance combined with digital subtraction angiography (DSA) to completely remove the occluder, accumulating some experience.

The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation. After the surgery, the occluder fell off and became free in the left ventricle, which is very dangerous. We innovatively used ultrasound guidance, combined with DSA, and interventional surgery to successfully capture the free occluder using a catcher, completely remove it, and then re implant a new left atrial appendage occluder. After the surgery, the patient recovered very well.

The size selection of the occluder is slightly conservative, and the shape of the left atrial appendage opening is irregular.

Left atrial appendage occluder detachment is one of the most serious complications of left atrial appendage occlusion, but the incidence is low, and most treatment measures are removal after thoracotomy. In this case, we innovatively used ultrasound combined with digital subtraction angiography (DSA) guided percutaneous intervention surgery to successfully remove the detached occluder.

(1) Cardiogenic syncope; and (2) persistent atrial fibrillation.

Considering that the patient had a history of gastrointestinal bleeding and a high risk of stroke and bleeding, left atrial appendage closure surgery was planned after the team was able to communicate with the patient and his family members.

At 08:00 am on September 12, 2023, the surgery was performed under the guidance of DSA and transthoracic echocardiography. After a successful atrial septal puncture, the pigtail catheter was sent along the outer sheath to the left atrial appendage for an imaging examination (Figure 1A). The inner diameter and opening diameter of the left atrial appendage were measured, and LACbes 22 mm were configured in vitro according to the size of the patient's left atrial appendage × 32 mm of the occluded left atrial appendage. Under radiographic guidance, the occlusion was adjusted to the left atrial appendage, and with the assistance of RAOSO+CAU20 imaging, the occlusion umbrella was released. Radiography revealed that the occlusion umbrella was stable at the left atrial appendage opening, and the imaging showed that the left atrial appendage had been isolated from the left atrial blood flow (Figure 1B). A traction test was performed for another minute. RAOS0+CAU20 confirmed that the occlusion umbrella was firmly fixed, and there was no obvious leakage of contrast agent around the umbrella. The occlusion was, accordingly, considered satisfactory. Cardiac ultrasound examination showed that the occlusion umbrella was stably fixed at the opening of the left atrial appendage, and no blood flow signal was observed from the left atrial appendage or left atrium around the umbrella (Figure 1C), indicating successful occlusion of the left atrial appendage. Under radiographic guidance, the separation and delivery system, and the sealing umbrella were separated. Postoperatively, the patient's vital signs were stable, and the puncture point was ligated with sheath removal and pressure. The patient returned to the ward safely.

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Figure 1 First surgery: Left atrial appendage occlusion. A: Left atrial appendage angiography before occlusion; B: Before the release of LACbes 22 mm × 32 mm occluder, no leakage of contrast agent was obvious around the umbrella during the imaging examination; C: Transthoracic echocardiography shows that the occluder is fixed to the opening of the left atrial appendage, and no blood flow signal is observed from the left atrial appendage or left atrium around the umbrella.

At 9:37 am on September 13, 2023, the patient visited the ultrasound imaging department for a follow-up cardiac ultrasound examination, which showed that the occluder had fallen off and was free in the left ventricle (Figure 2). CT confirmed this finding. After consultation with the superior hospital staff, the left atrial appendage occluder was removed and a left atrial appendage occlusion was performed at 18:35 on the same day. After a successful atrial septal puncture, a Medtronic 4FC12 adjustable sheath was inserted, followed by a 7F AL1 guide tube to the left ventricle along the adjustable bent sheath. The occluder grasping device was inserted along the guide tube, and the occluder was grasped under ultrasound guidance and X-ray fluoroscopy (Figure 3A). After successfully capturing the occluder, ice saline was injected along the adjustable curved sheath to soften the occluder (Figure 3B), and it was grabbed successfully by the sheath (Figure 3C and D). The occluder was successfully removed (Figure 3E), and the patient's vital signs were stable without any special discomfort reported. In this way, an in vitro configuration LACbes 26 mm × 32 mm left atrial appendage occlusion was performed. Under radiographic guidance, the occlusion umbrella was adjusted to the left atrial appendage, and with the assistance of RAOS0+CAU20 imaging, the occlusion was released. Radiography revealed that the occlusion was stable at the left atrial appendage opening, and the imaging showed that the left atrial appendage was isolated from the left atrial blood flow. A traction test was performed for another minute. RAOS0+CAU20 confirmed that the occlusion was fixed and there was no obvious leakage of contrast agent around the umbrella, indicating the satisfactory completion of the surgery.

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Figure 2  Occluder detachment and detachment into the left ventricle.

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Figure 3 Second surgery. A: Catcher capture blocker; B: Successful capture of the occluder and injected ice salt water along the sheath to soften the occluder; C: Partial recovery of the occluder into the sheath and withdrawal from the sheath; D: Complete recovery of the occluder into the sheath; E: Successful removal of the occluder.

After a cardiac ultrasound examination conducted immediately postoperatively, it was evident that the closure umbrella was stably fixed at the left atrial appendage opening. No blood flow signal was observed from the left atrial appendage or left atrium around the umbrella. There was a small amount of mitral regurgitation, a small amount of septal blood flow was observed in the middle of the atrial septum, and no fluid accumulation was obvious in the pericardial cavity, indicating successful closure of the left atrial appendage. Under radiographic guidance, the conveying system and sealing umbrella had been separated. Postoperatively, the patient's vital signs were stable, and the puncture point of the pressure package was removed. The patient returned to the ward safely.

The next morning, a follow-up cardiac ultrasound was performed, and the closure umbrella was stably fixed at the left atrial appendage opening (Figure 4A). Mild mitral regurgitation was observed, and a shunt signal with a width of approximately 4mm was observed at the atrial septal puncture site (Figure 4B).

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Figure 4 Transthoracic echocardiography. A: Transthoracic echocardiography shows the occluder located at the left atrial appendage opening; B: Transseptal blood flow at the puncture site of the atrial septum.

The left atrial appendage is the most prone site for atrial thrombus formation during atrial fibrillation, and stroke is among the most common complications of atrial fibrillation[1]. This patient with atrial fibrillation had a history of gastric bleeding and was unwilling to receive long-term oral anticoagulant therapy. After a multidisciplinary consultation, and after hearing the opinions of the patient and his family, left atrial appendage closure surgery was performed. An unpredictable occluder detachment occurred postoperatively.

The detachment of occluders is among the most serious complications of left atrial appendage closure surgery, but the incidence is low. Not many cases have been reported at home and abroad[2], and most remedial measures are thoracotomy and removal. In this case, ultrasound combined with DSA-guided percutaneous intervention was used to successfully remove the detached occluder[3].

The method used is as follows: under ultrasound guidance, the occluder was clamped and fixed in the left ventricle using toothed forceps in the occluder, and ice saline was injected into the sheath to fully soften the occluder. After fully softening the occluder, it was pulled into the sheath as much as possible, and withdrawn through the mitral valve, left atrium, atrial septum, right atrium, and inferior vena cava.

The surgical approach is summarized as follows: (1) Fully softening the occluder with ice saline is the key step of the entire surgery; (2) transthoracic ultrasound combined with DSA guidance is an important means of quickly capturing the occlude; (3) during the process of grasping and capturing the occluder, toothed forceps should be selected, but physical damage to structures such as the valves, tendons, or myocardium, must be avoided; (4) it is necessary to immediately evaluate the mechanical damage to structures such as the mitral valve and atrial septum using ultrasound after removing the original sealing device; and (5) finally, the detachment of the occluder may be caused by the irregular shape of the left atrial appendage opening and the slightly conservative size selection of the occluder.