ASD device closure has become a de-facto modality for most ostium secundum defects(<35mm). The stupendous success of this procedure is attributed to careful pre and Intra-procedural Imaging, new generation hardware and of course the ever-improving expertise among Interventional cardiologists.
Still, there is one issue that is bothersome. It is the late complications of this device and the need for follow-up (Unlike surgery where close and forget option seems real and confer lot of comforts) The delayed mechanical complications are now extremely rare still follow up of these patients is advised.
What is the mechanism of Aortic erosion in ASD device closure ?
The IAS is a dynamic structure. (Ask any echoc’ardiographer ,how ASD size varies with cardiac cycle.) The device should sit right across all rims including the Aortic rim . If the device if larger , and if the Aortic rim is less it has on other option but to splay over the Aorta . Enthusiastic young cardiologists should be aware this splaying is not in our control at all. Not all splaying are good and safe as well. If its not smooth and if the septum is mal-aligned there could be friction Injury to Aorta. A very early manifestation of device dislodgement and later a trickle of pericardial effusion. This should be watched for. (Please be reminded a early pericardial minimal effusion due to sudden shrinkage of RA, RV and due to some unknown hypersensitivity response ? can confuse us )
Link between deficient Aortic rim and Erosion : An unsettled Issue (But , we settled it ! )
One issue that is poorly understood is, many Interventional cardiologists believe strongly that the length (and even quality) of Aortic rim is the least important and need not to be respected. I am still not clear on what basis this piece of Interventional literature came in. This is exactly is the reason even novices take liberty and large devices are implanted casually encroaching the Aorta. Though most cardiologists shrug of this risk of Aortic rim deficiency and subsequent erosion, at least one study clearly showed a serious link between the two. I feel the issue is not yet settled and demands re-scrutiny.
This presentation was made in Tamil Nadu Interventional (TIC)council meet at held recently
Link to the PPT presentation aortic erosion 2
Final message
After going through all relevant literature as on 2019 , the incidence of aortic erosion is rare but the fear is real (Many feel it is paranoid and largely unfounded ) I won’t agree though.The message must be, a good quality Aortic rim is important too.
However, a properly sized device, perfectly delivered with good Image assistance by a trained cardiologist in a high volume center (? >25/year) shall prevail over surgery in most patients with ASD.
Reference
One more Issue with ASD closure device is delayed embolic episodes from thrombus attached to device. This is prevented by routine anti platelet drugs practiced by certain Institutions .The new generation devices (Occlutech Germany) has modified the LA side of the disc (No Hub) to reduce this risk
