Very late thrombosis of Amplatzer septal occluder device: a case report

Device-related thrombosis is a rare but recognized complication following transcatheter atrial septal defect (ASD) closure, typically occurring within the first-year post-implantation. While early thrombus formation has been documented, very late presentations remain exceedingly uncommon.

We report a case of delayed device-associated thrombosis occurring 23 years after ASD closure with a 36 mm Amplatzer device. A 75-year-old female with multiple cardiovascular risk factors presented with acute left upper limb weakness, dysphagia, and slurred speech. Neuroimaging revealed infarcts in the right middle cerebral artery territory, consistent with an ischaemic stroke. Transthoracic echocardiography (TTE) identified a mass on the left atrial surface of the device. Transoesophageal echocardiography (TOE) confirmed a mobile thrombus on the right atrial surface and a sessile mass on the left atrial disc. There was no residual shunting. The patient was commenced on anticoagulation.

This case represents the most delayed instance of device-associated thrombosis reported to our knowledge. It highlights the diagnostic value of TOE when TTE is inconclusive and underscores the need for individualized anticoagulation strategies. Given the increasing use of transcatheter closure devices, this case raises important questions regarding the optimal duration of post-implantation surveillance, especially in elderly patients with comorbidities. A tailored follow-up approach may be warranted to mitigate late complications.

Clinicians should maintain vigilance for device-associated thrombosis even decades after percutaneous ASD closure, particularly in patients with embolic phenomena. Extended surveillance imaging may be necessary in patients with significant comorbidities and risk factors.