Introduction
Although aortic regurgitation is recognised as a possible complication after device closure of atrial septal defects, Reference Schoen, Boscheri and Lange1 its mechanism is not clearly understood. While only a limited number of cases with severe aortic regurgitation have been reported, Reference Prasad, Singh, Dharan, Gopalakrishnan and Krishnamoorthy2 minor aortic regurgitation can sometimes be observed after implantation of the device. Reference Schoen, Boscheri and Lange1,Reference Mirzada, Ladenvall and Johansson3 Regardless of the relatively low risk of developing infectious endocarditis after device atrial septal defect closure, newly developed aortic regurgitation can additively increase this risk. Reference Chatrath, Dargan and Kaza4,Reference Yamanaka, Higashitani, Ichinohe, Fukatsu and Kunihara5 Here, we report the case of newly developed aortic regurgitation late after atrial septal defect device closure, which worsened with patient growth at first, but it became consistent or even mildly ameliorated after years of observation, presumably due to adaptation of the device.
Case presentation
A 7-year-old boy (height: 127 cm, weight: 24.6 kg) was admitted for device closure of a secundum atrial septal defect (Figure 1(a)). The diameter of the atrial septal defect was 7.9 × 9.8 mm, without deficiency of the surrounding rims (superior vena cava: 9.8 mm, right upper pulmonary vein: 12.7 mm, inferior vena cava: 18.5 mm, atrioventricular valve [mitral/tricuspid]: 9.0/12.3 mm, superior: 14.7 mm, posterior: 10.5 mm, aortic: 4.0 mm, and coronary sinus: 10.2 mm). The total atrial septal length was 26.0 × 28.8 mm, and a 10-mm Amplatzer septal occluder (ASO; left atrial disk, 26 mm; right atrial disk, 18 mm, St. Jude Medical, Plymouth, MN) was successfully deployed. Echocardiography revealed no device contact with the aortic sinus (Figure 1(b)). The aortic valve was tricuspid and functionally competent, without restriction of the leaflet motion. The device position was consistent, and no aortic regurgitation was observed at 1, 3, and 6 months after implantation on transthoracic echocardiography (Figure 2).
Transesophageal echocardiography during the procedure. ( a ) Atrial septal defect (ASD) before device closure. Transesophageal echocardiography before ASD device closure is shown. The ASD was 7.9 × 9.8 mm in diameter, without a deficiency of the surrounding rims. The total atrial septal length was 26.0 × 28.8 mm in size. ( b ) Post ASD closure. A 10-mm Amplatzer septal occluder (St. Jude Medical, Plymouth, MN) was deployed, and no residual shunt was identified (image is not shown). The device was not attached to the aortic sinus immediately after the ASD closure.
Figure 1. Long description
Transesophageal echocardiography images display the atrial septal defect before and after device closure. The first set of images (a) shows the atrial septal defect at angles of 0 degrees, 60 degrees, and 100 degrees. The defect measures 7.9 by 9.8 millimeters in diameter, with intact surrounding rims. The total atrial septal length is 26.0 by 28.8 millimeters. The second image (b) shows the post-closure state with a 10-millimeter Amplatzer septal occluder deployed, indicating no residual shunt. The device is not attached to the aortic sinus immediately after the closure.
Chronological change in the relationship between the device and non-coronary sinus, and aortic regurgitation. The chronological change in the relationship between the device and non-coronary sinus in systole and diastole (upper two lines) and aortic regurgitation (lower two lines indicating short- and long-axis images) is shown. Although there was no aortic regurgitation initially, it was first identified at 1 year of device deployment from the commissure between the right and left coronary cusps. The aortic sinus appeared more compressed during diastole than during systole, which gradually increased until three years after device closure. In addition, the device appeared to rotate clockwise toward the LA, by which the RA disk compressed the non-coronary sinus and changed the shape of the atrial septum (yellow arrow), might have exacerbated deformation of the aortic sinus. Although AR worsened for four years after deployment, it became attenuated in the ninth year, with an increased distance between the device and the aortic sinus and improved alignment of the device.
Figure 2. Long description
The image displays a series of echocardiographic images arranged in a grid. The rows are labeled as Systole, Diastole, Aortic long axis, and Aortic short axis, while the columns are labeled with time intervals: 6 months, 1st year, 3rd year, 4th year, and 9th year. Each cell contains an echocardiographic image showing the relationship between a device and the non-coronary sinus. The images highlight changes in the aortic regurgitation and the positioning of the device over time. The yellow arrows in the 4th year images indicate the rotation of the device and its impact on the aortic sinus.
After a year of deployment, transthoracic echocardiography revealed a newly developed aortic regurgitation (Figure 2). The device contact of the aortic sinus seems to become more robust during diastole than during systole. The patient had no history of chest trauma or streptococcal infection, and screening for infective endocarditis and cardiomyopathy was negative. After three years of atrial septal defect closure, the aortic regurgitation worsened to mild grade, originating from the commissure between the left and right coronary cusps (Figure 2). In the 4th year, a regurgitant jet was observed from the centre of the coaptation, in addition to the commissure of the right and left coronary cusps. The Amplatzer septal occluder device gradually attached to the aortic sinus, particularly during diastole, with a pronounced Doppler signal of aortic regurgitation. The relatively large aortic sinus during childhood Reference Poutanen, Tikanoja, Sairanen and Jokinen6 and rapid increase in left atrial volume index, coupled with the attenuation of right atrial volume index after atrial septal defect device deployment, might have contributed to the progressive compression and/or traction of the aortic sinus, particularly at the 4th year (Figure 3). After 9 years of Amplatzer septal occluder deployment, when the diameter of the aortic sinus corrected with body surface area became attenuated, and the discrepancy between left atrial volume index and right atrial volume index was suppressed, the degree of aortic regurgitation appeared to be mildly attenuated with an increased distance between the aortic sinus and the device.
Trends of the Aortic sinus diameter and the left atrial volume index after device atrial septal defect closure. The aortic sinus diameter early after atrial septal defect (ASD) closure was large compared with the body surface area (BSA), which gradually decreased with patient’s growth. Inversely, the left atrial volume index increased rapidly from 20 to 35 ml/m2 in 5 years, and then it was suppressed to 5 ml/m2 (from 35 to 40 ml/m2) in the subsequent 4 years. Meanwhile, the right atrial volume attenuated and became minimal at four years after deployment, which might have contributed to the geometrical change of the atrial septum, observed in Figure 2 (yellow arrows). Red solid circle: left atrial volume index, Black solid circle: right atrial volume index, Blue solid circle: aortic sinus diameter.
Figure 3. Long description
A line graph displays trends of aortic sinus diameter and left atrial volume index after device atrial septal defect closure. The x-axis represents years after deployment, ranging from before the procedure to nine years post-deployment. The left y-axis represents the left atrial volume index and right atrial volume index in milliliters per square meter, ranging from 15 to 45. The right y-axis represents the aortic sinus diameter in centimeters per square meter, ranging from 1 to 2.5. The red line indicates the left atrial volume index, the black line indicates the right atrial volume index, and the blue line indicates the aortic sinus diameter. Key events such as the onset of aortic regurgitation, significant aortic regurgitation, location of aortic regurgitation, device angle change, and aortic regurgitation improvement are marked with arrows. The left atrial volume index increases rapidly initially and then stabilizes, while the right atrial volume index decreases and stabilizes. The aortic sinus diameter decreases gradually over time. All values are approximated.
Discussion
While deployed atrial septal defect occlusion devices contact the aortic sinus in 79% of patients with an aortic rim ≧5 mm and 100% of those <5 mm, Reference Abdelghani, Nassif and de Bruin-Bon7 clinically significant worsening of aortic regurgitation is observed in approximately 0.6 % during mid-term observations. Reference Loar, Johnson and Cabalka8 Despite rarity of this condition, it can be clinically significant, as those with aortic regurgitation are at risk of developing infective endocarditis, which requires life-long prophylaxis. We report a case in which aortic regurgitation occurred late after atrial septal defect device closure, which was assumed to originate from progressive device contact with the aortic sinus, particularly during diastole. Another 5 years of follow-up revealed attenuation of aortic regurgitation, which was simultaneously observed with the increased distance between the device and the aortic sinus.
Haemodynamically negligible aortic regurgitation is observed in as often as 9–17% of patients after atrial septal defect device closure, Reference Schoen, Boscheri and Lange1,Reference Mirzada, Ladenvall and Johansson3 implying progressive aortic deformity to a greater or lesser extent. Although the mechanism of aortic regurgitation development after atrial septal defect device closure is not fully understood, device oversizing is a plausible cause. In our case, a 10 mm device was chosen to close a 9.8 mm atrial septal defect in diameter, which was unlikely to be too large for the defect. However, the age/device size ratio and weight/device size ratio were 0.70 year/mm and 2.46 kg/mm, respectively, which might indicate a high risk for erosion, although it was not the extreme accounting for the patient’s age. Reference McElhinney, Quartermain, Kenny, Alboliras and Amin9 Prasad et al. reported a case of significant aortic regurgitation developing two years after device closure of atrial septal defects, where the deployed device size was only 1 mm larger than the defect size, and no signs of erosion were observed even in the intraoperative findings of device retrieval. Reference Prasad, Singh, Dharan, Gopalakrishnan and Krishnamoorthy2 In this case, the age/device size ratio and weight/device size ratio were 0.63 year/mm and 1.50 kg/mm, respectively. Based on this case and ours, a large device size relative to body size might be associated with the late development of aortic regurgitation, similar to its relationship with cardiac erosion.
The majority of atrial septal defect devices contact the aortic sinus, and their relationship with the aortic sinus remains the same during years of observation. Reference Abdelghani, Nassif and de Bruin-Bon7,Reference Gossett, Mansfield, Acevedo, Lay, Rychlik and Wax10 Nevertheless, the distance between the aortic sinus and the device appeared to be close and have contributed to aortic regurgitation in our case. Indeed, aortic regurgitation was located in the commissure between the left and right coronary cusps, which should be associated with the deformity of the non-coronary sinus, as was evident in the ex vivo experiment of the relationship between cusp deformation and location of regurgitant jet. Reference Zhu, Park, Imbrie-Moore, Wilkerson, Madira and Woo11 Shoen et al. speculated that in patients after device PFO closure, the changes in interatrial septal geometry and traction on the root of the non-coronary aortic cusp might be induced by the overgrowth of the device by the surrounding tissue. Reference Schoen, Boscheri and Lange1 In our case, the size of the left atrium increased, whereas that of the right atrium decreased in the first few years (Figure 3), which may have altered the angle between the atrial septum and aortic sinus, contributing to the exacerbation of aortic regurgitation by non-coronary sinus compression and traction by the device. (Figure 2, yellow arrow). Kijima et al. reported the impact of device alignment on the development of significant erosion, although our patient originally did not have anatomical septal malalignment or aortic rim deficiency which might somehow reduce the compression and avoid erosion. Reference Kijima, Akagi and Nakagawa12 While ventricular diastolic dysfunction and left atrial malfunction have been reported to develop after the deployment of the Amplatzer septal occluder, Reference Suzuki, Kato and Koyama13,Reference Lange, Coleman, Palka, Burstow, Wilkinson and Godman14 this patient did not exhibit symptoms of circulatory failure or diastolic dysfunction, and the rate of left atrial volume increase slowed after 5 years of closure (Figure 3). Although the detailed mechanism of left atrial enlargement remains unclear, Seo et al. analysed 20 adult patients after atrial septal defect device closure, and their left atrial volume was 59.1 ± 28.9 mL, Reference Seo, Park and Wi15 which is consistent with this patient.
In addition to the direct impact of the device, changes in aortic sinus diameter may have affected the development as well as subsequent amelioration of aortic regurgitation. Consistent with a previous report, Reference Poutanen, Tikanoja, Sairanen and Jokinen6 the diameter of the aortic sinus normalised to the body surface area (BSA) in our patient was initially large (Figure 3) and gradually attenuated with age. Although the origin of the device interaction with the aortic sinus appeared to be multifactorial, patient growth, which is associated with the attenuation of the aortic sinus diameter compared to body size, might have contributed to the later improvement of aortic regurgitation in this patient.
In summary, our case highlights the possibility of delayed-onset aortic regurgitation due to the interaction between the atrial septal defect device and cardiac structure. Given that the interaction between the device and the aortic valve can vary among individuals, flexible devices may be a better option for children or those with a small body size. Aortic regurgitation in our patient gradually attenuated over 10 years of deployment, underscoring the importance of following up on the adaptation of the device to somatic growth.
Limitation
Although exercise testing might contrast the change in aortic regurgitation or might elucidate the impact of the device on the morphological changes in the aortic sinus, we unfortunately do not have sufficient data for this. The mechanism of delayed-onset aortic regurgitation could be multifactorial, and we could not specify the primary source of aortic regurgitation in this case. Meticulous research on device interactions with the aortic sinus is necessary to identify the risk factors for aortic deformities in paediatric device atrial septal defect closure.
Conclusions
Even in the absence of apparent aortic compression, aortic regurgitation can develop late after atrial septal defect device treatment. Both the changes in cardiac function and the relationship between the device and the aorta are assumed to have attributed to the late development and progression of aortic regurgitation in our patient. However, it is difficult to predict the degree of postoperative diastolic dysfunction, changes in left atrial volume, and aortic sinus characteristics during the cardiac cycle. Our case highlights the need for long-term post-procedural follow-up in atrial septal defect device closure, particularly in growing children. Various device options other than Amplatzer septal occluder are currently available; thus, it is important to continue posttreatment evaluations and accumulate cases, including whether similar cases occur with other, more flexible devices.
Financial support
None.
Competing interests
None.
Ethical standards
The patient and guardian provided consent for the presentation of the clinical course of this patient.
