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Atrial septal defect (ASD) is a congenital heart defect that is being increasingly treated using percutaneous interventions. However, these techniques are not devoid of complications. One such complication is device embolization. Removal of such closure device poses tremendous risk and consequent complications both by percutaneous retrieval and surgical removal. Herein, we present two cases of ASDs that were closed using atrial septal occluder, but the devices were subsequently embolized into left atrium. These devices were then percutaneously retrieved without any further complication or injury.
Atrial septal defect (ASD) represents insufficiency of the tissue, tiny to substantial, in the atrial septum . It constitutes 7%–10% of the congenital heart defects in adults . At inception, surgery was considered to be the gold standard method for ASD closure [3, 4]. But, with time, percutaneous ASD closure was found to be an alternative to the surgical closure, as it had lower rates of morbidity, shorter hospital stay, and lack of a scar [4, 5]. However, percutaneous ASD closure also showed various complications [6, 7]. One such complication is device embolization, which occurs in up to 0.5% of cases even when the interventionalists are experienced .
Aspects related to risk of device embolization were the type of device used, larger size of defect with floppy rim, thin rim of atrial tissue, change in the position of device post-deployment, and the use of undersized device [3, 9].
The time of device embolization after its implantation was erratic in various situations. Some cases reported immediate embolization , whereas other cases reported it to occur from several days to several months after the procedure [10, 11]. Percutaneous and surgical methods were applied for retrieval of the embolized device . Use of large sheaths, snares, or endomyocardial biopsy forceps  along with the assistance of stiff guidewire  or a bioptome [15, 16] led to successful percutaneous retrieval of devices. Herein, we present two similar yet different cases of immediate embolization of ASD closure device and their successful percutaneous retrieval, followed by surgical closure of the ASD.
A 44-year-old woman checked in our institute with the complaint of increasing shortness of breath on exertion and fatigue. Oxygen saturation, determined by pulse oximetry, was found to be normal. On physical examination, ejection systolic murmur was audible in the pulmonary area, and there was a wide, fixed splitting of second heart sound (S2). ECG examination revealed sinus rhythm with QRS axis of 100°. Also, a distinct rSr’ pattern was observed in lead V1. Chest X-ray exhibited a cardiothoracic ratio of 55% with prominent pulmonary artery shadow. Transthoracic echocardiography showed a 26-mm secundum ASD with dilated right atrium, right ventricle, and left to right shunt. Transesophageal echocardiography (TEE), which was performed to determine whether defect was suitable for percutaneous closure, also revealed a 30-mm secundum ASD along with adequate rims except the inferior vena cava (IVC) rim and posterior rims, which was slightly thin and flimsy. The patient underwent percutaneous closure of secundum-type ASD with atrial septal occluder (ASO).
As IVC rim and posterior rims were inadequate, a large 34-mm Cera ASD occluder [Lifetech Scientific (Shenzhen) Co. Ltd., China] device was chosen for the ASD closure. As per the standard procedure, a 6-Fr multipurpose catheter and a 0.035-in. Amplatz exchange guidewire (Boston Scientific, Marlborough, MA) were used to cross the ASD and enter the left upper pulmonary vein and the device was placed; but soon it was observed that the device was not being properly placed, so it was recaptured and the procedure was repeated through the right upper pulmonary vein. On this attempt, position of the device seemed correct and it was placed (Fig. 1A).
Few minutes after the placement of the device, while performing echocardiography, the device moved from its initial position (Fig. 1B). Consequently, it was embolized into the left atrium (LA). As the device was large, there was a possibility that the device may obstruct the mitral inflow. So, cardiovascular surgeons were immediately informed, and percutaneous retrieval was attempted, while preparing for surgery. To prevent thrombus formation, extra unfractionated heparin was given to maintain activated clotting time above 200 s.
Initially, attempts were made to hold the right atrial (RA) screw with indigenous snare. This snare was found to be large. Moreover, this snare was not being properly aligned with the RA disk screw. Then, a 15-mm Amplatz gooseneck snare (eV3 Endovascular, Inc., Plymouth, MN) was used. Multiple views were used to locate the device position. As the device was large and less mobile, the RA disk screw was properly held through the snare (Fig. 1C). Thereafter, the device was successfully recaptured back in 14-Fr delivery sheath without any entanglement or complications (Fig. 1D). Repositioning of the device was not attempted because of inadequate IVC rim and posterior rims; moreover, a large device was already used. Patient was then referred for elective surgery.
A 45-year-old woman checked in our institute with shortness of breath (NYHA class II). She was diabetic and hypertensive. TEE showed situs solitus with congenital heart disease, depicting a 24-mm large ostium secundum ASD with left to right shunt, with some adequate and some deficient rims. Moreover, TEE also showed ASD size of 24 mm. Patient was taken for transcatheter closure of ASD. A 26-mm Cera ASD occluder [Lifetech Scientific (Shenzhen) Co. Ltd., China] device was successfully placed across ASD (Fig. 2A). Few minutes after the placement of the device, patient complained of giddiness in cath ward. Therefore, echocardiography was re-performed, which showed that the device had embolized into LA (Fig. 2B). It was decided to retrieve the device percutaneously. A 15-mm Amplatz gooseneck snare (eV3 Endovascular, Inc., Plymouth, MN) was passed through a 6-Fr multipurpose catheter through 14-Fr Cook’s sheath. But the device could not be caught with gooseneck snare. Therefore, an indigenous snare with 300-cm cougar wire was used. With the help of indigenous snare, the device was held at screw point and pulled into the Cook’s sheath. The RA disk entered into the Cook’s sheath, but later the indigenous snare slipped out (Fig. 2C). Further attempts to catch the device with the indigenous snare failed. Therefore, a 15-mm Amplatz gooseneck snare, passed into the 14-Fr Cook’s sheath over 6-Fr multipurpose catheter, caught the device and pulled the whole device (Fig. 2D). Before pulling the device, a wire was passed through the Cook’s sheath to maintain access. The retrieval of the device was successful (Fig. 3), without any further complication.
After the removal of embolized device, the same procedure was repeated, and the same device was placed across ASD. But it was felt that the size of device was small so that device was replaced with another 30-mm Cera ASD occluder [Lifetech Scientific (Shenzhen) Co. Ltd., China]. On echocardiography, this new device was found to be impinging on mitral valve. Therefore, it was taken out, and the patient was sent for elective surgery.
This report presented the cases of two patients who underwent percutaneous ASD closure with ASO devices followed by device embolization and subsequent successful percutaneous retrieval of each device. These two cases differed in sizes of ASD and in symptoms of embolization (i.e., one patient was asymptomatic but was diagnosed incidentally when performing post-procedural echocardiography and the other patient experienced giddiness). Although there was disparity between both cases, similarity was that some rims in both the patients were adequate and some were slightly deficient, the embolization of device was immediate in both cases, and the location of embolization and overall method of retrieval were identical.
As mentioned earlier, there were many reasons for embolization of ASD closure devices. The most common being undersized ASD device and the other most common being inadequacy of ASD rims. To the best of our knowledge, inadequate rim was the cause of embolization in the first case, leading to the use of oversized device. In the second case, the embolization was probably because of the deficient rims and undersized device. Device embolization because of inadequate IVC rim has been reported earlier by Kannan et al. , Varma et al. , and Remadevi et al. .
In both our cases, the detection of device embolization was early, and therefore, the device was restricted to the LA without being further migrated into different locations, where it would have been difficult for percutaneous retrieval. But in some other case reports, the devices were found to be embolized to pulmonary artery , right ventricle , and even abdominal aorta , where the percutaneous retrieval of the device becomes difficult leading to surgery.
The first step in retrieval was stabilizing the device by preventing its migration and subsequently slenderizing it. Some researchers have used stiff guidewire, which was passed across the mesh of the device for stabilization , whereas others have used a bioptome to stabilize the LA disk of device and to restrict the movement [8, 15, 16]. However, none of the above techniques were used in our cases as the devices used herein were large and less mobile. Instead, multiple views to catch hold of the RA disk screw with snare were used. There are many studies that have reported the use of snare for retrieval of embolized ASD closure devices from different locations in body [14, 15].
The second step in retrieval was pulling ASO into sheath using the screw on RA disk. To pull the device into sheath, proper application of force and degree of alignment of device with the sheath were imperative . A 2-Fr sheath larger than the proper fit delivery sheath, use of stiff sheath that are less likely to kink, and cutting a bevel at distal end of sheath to facilitate entry of RA disk screw into the sheath assist easy retrieval of the device out of the body . In our cases, 14-Fr sheath was used because the devices were large.
In both our cases, retrieval was successful without any further complication or vessel injury. It is important to protect the device with the sheath while retrieving to prevent injury to valves and chambers of heart and blood vessels.
This report underscores the importance of careful selection of appropriate approach for ASD closure depending on patient peculiarities and thereby close monitoring for occurrence of early embolization or complications as well as monitoring the possibilities of delayed complications. Percutaneous retrieval should be attempted before sending the patient to surgery on an emergency basis. All interventionalists should be aware of retrieval techniques.
RR, SP, and CNM: interventional procedure, final approval of the version to be published. NS, JK, BP, and JMR: literature review and drafting of the manuscript, final approval of the version to be published. All authors had full access to all data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
The authors declare no conflict of interest.
Funding sources: No financial support was received for this study.