secundum type atrial septal defect ( asd ) is one of the most common congenital heart defects that occur in adults.1 ) in the past , asd was closed surgically .
percutaneous device closure of asd has been developed as an alternative treatment to surgery.2 ) the first percutaneous device closure of asd was performed in 1974.3 ) percutaneous device closure has several advantages over surgery , including less surgical morbidity , avoidance of a scar and reduced hospitalization duration.4 ) however , this method of closure is associated with rare early and late complications .
we report a rare complication of silent and late device embolization of the asd occluder device into the right pulmonary artery , three months after implantation .
a 16 year - old patient presented with dyspnea . clinical examination revealed normal vital parameters with a fixed split second heart sound and a 2/6 systolic ejection murmur heard best at the left upper sternal border .
the patient was initially evaluated by transthoracic echocardiography ( tte ) and had a typical ostium secundum type asd .
transesophageal echocardiography ( tee ) confirmed the presence of a moderately large sized secundum asd that measured 20 mm .
the aortic rim was almost absent ( 2 - 3 mm ) with other surrounding rims > 7 mm ( not thin ) .
the length of the interatrial septum was 45 mm in the longitudinal plane and 48 mm in the shortaxis view .
the 30 mm sizing balloon was positioned across the defect and measured by both quantitative angiography and tee at 21 mm . a 24-mm asd septal occluder device ( occlutech figulla asd occluder n
, international occlutech ab , helsingborg , sweden ) was deployed with fluoroscopic and transesophageal echocardiographic guidance . before releasing the device , fluoroscopy and the " minnesota tug technique "
cessation of flow across the interatrial septum was confirmed on tee prior to final deployment of device .
tte was performed 24 hours , seven days and one month after the implantation and confirmed adequate device position with no significant residual shunting . at the third month physical examination , a fixed split second heart sound and a systolic ejection murmur
chest roentgenogram showed the asd closure device in the area of the right pulmonary artery ( fig .
echocardiography showed device migration into the right pulmonary artery without any significant obstruction to forward flow into the right pulmonary artery ( fig .
when the patient was interviewed again , he had complained of mild chest discomfort for a short duration during lifting of a heavy object fifteen days prior to being seen .
right ventriculography and fluoroscopy also showed embolization of the device into the right pulmonary artery ( fig .
3 ) . percutaneous removal of the device was not considered because of the position of the device in the right pulmonary artery .
the patient was referred for surgical retrieval of the device and closure of the defect , and underwent median sternotomy under general anesthesia , while cardiopulmonary bypass was performed by aorta - bicaval cannulation .
asd closure device was removed out of the right pulmonary artery through arteriotomy performed on the main pulmonary artery , and secundum type asd primary closure operation was performed through the right atriotomy . following surgical retrieval , the device was macroscopically intact ( fig .
there were no problems in the postoperative follow - ups ; additionally there was no leakage from atrial septum in the follow - up echocardiography .
surgical closure of an asd is the gold standard treatment regardless of the size and number of defects present in any clinical case.2)5 ) percutaneous transcatheter closure of asd is an established alternative treatment to surgical closure as it has lesser morbidity , shorter hospital stay , lack of a scar , and comparable rates of complications.4 - 6 ) however , percutaneous device closure is associated with rare early and late complications such as migration or embolization of the device , pericardial effusion , arrhythmias , thrombus formation on the device , and mitral regurgitation and vascular injury.4)7)8 ) the most frequent complication of percutaneous transcatheter closure of asd is device embolization with incidence ranging from 4% to 21%.9 ) embolization usually occurs within 24 hours and after that , it is rarely seen .
factors relating to device embolization are associated with the type of device used , larger size of defect , thin rim of atrial tissue , mobility of device postimplantation , use of undersized device and deficiency or absence of aortic rim.2)4)7)8 ) the aortic rim is very important and a margin < 5 mm may predispose to both early and late device embolization.2 ) our patient had a moderately large secundum asd and very small aortic rim ( 2 - 3 mm ) , the combination of which may have resulted in embolization of the device at a late period .
another potential cause of late device embolism is acute change in intracardiac pressure due to physical strain .
a sudden increase in afterload to the left heart in conjunction with diminished right heart filling ( valsalva ) may have favored the migration of the device to the right and subsequently to the pulmonary artery.10 ) ten weeks after the procedure , when the patient was lifting a heavy object , he had complained of mild chest discomfort for a short duration of time .
the history of our patient suggests that an acute change in intracardiac pressure due to physical strain may have dislodged the device .
therefore , we believed that both physical strain and small aortic rim were possible causes for device embolism in our patent .
we routinely advise to avoid heavy lifting for 3 months in all asd patients who are treated with percutaneous device closure .
stricter and longer duration of avoidance of heavy lifting should have been recommended for patients with increased risk of device embolism , as in our case .
mashman et al.10 ) also recommended 6 months of avoidance from strenuous exercise for decreasing embolic risk .
devices usually embolize in the main pulmonary artery.7 ) if the device embolizes to the pulmonary circulation and impedes pulmonary flow , it may lead to both acute volume and pressure overload of the right ventricular . according to the degree of pulmonary flow impairment
, constitutional symptoms usually developed.2 ) in our patient , it was embolized to the right pulmonary artery .
it is fortunate that the device position in the right pulmonary artery was in the longitudinal axis in our patient .
because the pulmonary flow was not influenced by the embolized device , our patient was asymptomatic .
if the device is embolized , percutaneous or surgical removal of the device is indicated.7 ) in our case , percutaneous treatment was not considered because of the orientation of the device in the right pulmonary artery , which precluded snaring the device and the chronicity of the implantation .
device embolism , which is the most frequent complication of percutaneous transcatheter closure of asd , may also occur during late periods of post - implantation .
in addition , longer duration of avoidance from physical straining must be recommended for patients who have high risk of device embolization .
 percutaneous device closure of atrial septal defect ( asd ) is an alternative treatment to surgery . 
 the main advantages of the percutaneous approach include avoidance of surgery , short procedure time and hospital length , in addition to comparable rates of complications . however , percutaneous device closure is associated with infrequent early and late complications including device embolization , air embolism , cardiac tamponade and thrombotic complications . 
 we report a rare complication of silent and late device embolization of the asd occluder device into the right pulmonary artery , three months after implantation . 