Initial presentation

The patient was diagnosed with an atrial septal defect at 6 months of age after discovery of a neonatal murmur. She was followed-up clinically for 4 years with minimal change in defect dimensions and was referred for transcatheter device closure after imaging revealed mild–moderate right ventricular volume overload. Before catheterisation, her echocardiogram demonstrated a 9.7×7-mm secundum atrial septal defect located posteriorly and inferiorly, with a deficient posterior rim and left-to-right flow.

Catheterisation procedure

The patient underwent catheterisation at 4.5 years of age. Her haemodynamics confirmed a significant left-to-right shunt through the atrial septal defect with a Qp:Qs of 3. Her right atrial pressure was mildly elevated with a mean of 7 mmHg and otherwise normal intra-cardiac pressures. The defect was balloon sized with a 20-mm PTS^® Balloon Catheter (B. Braun Interventional Systems Inc., Bethlehem, Pennsylvania, United States of America) to 12×13 mm. The stop flow diameter was 15 mm by fluoroscopy and transoesophageal echocardiogram. A 33-mm STARFlex device was delivered without complication via a 10-F Hausdorf-Lock Atrial, Performer ^TM Guiding Sheath (Cook^® Medical, Bloomington, Indiana, United States of America), and the defect was closed successfully. Immediately after the procedure, an echocardiogram demonstrated properly positioned device arms, with a moderate residual atrial shunt through the central portion of the device via multiple small jets. The following day, a pre-discharge echocardiogram confirmed stable device positioning and reduction in the residual shunt.

Follow-up

At the 3-month follow-up, an electrocardiogram was within normal limits with a QRS axis of +90°. An echocardiogram was notable for resolution of right ventricle dilation and indicated a stabilised device with no residual left-to-right shunting. It was recommended that the patient return in 1 year for further follow-up.

The patient re-presented to the cardiology clinic 5 years after her 3-month follow-up visit. In the interim, she had been followed-up routinely by her paediatrician without further cardiac evaluation, hospitalisation, or significant illness. A new heart murmur was detected at the patient’s annual checkup, prompting cardiac evaluation. Doppler imaging and two-dimensional echocardiography indicated either a shift in positioning of the device or loss of structural integrity compared with previous imaging. The echocardiogram showed a right atrial device arm on the left side of the septum and a left atrial device arm protruding within the left atrial lumen. A left-to-right shunt and a non-mobile, non-obstructive right atrial thrombus was detected on the posterior–inferior aspect of the device, with evidence of right ventricular volume overload (Fig 1). The patient was referred to the operating room for surgical removal of the device and thrombus. Preoperative imaging including an X-ray and intraoperative transoesophageal echocardiogram suggested a device arm fracture.

Figure 1

Schematic of the STARFlex device, thrombus, and atrial septal defect (ASD) as they appeared before explantation. IVC=inferior vena cava; RA=right atrium; SVC=superior vena cava.

Operative procedure

Under general endotracheal anaesthesia, the right atrium was opened and inspected. A large, bland thrombus was visualised, affixed to the right atrial aspect of the STARFlex device, and centred upon a broken arm that was protruding into the right atrial free wall (Supplementary Fig S1). The fractured device and the atrial septal defect on the posterior–inferior aspect were confirmed (Supplementary Fig S2). There appeared to be erosion posteriorly through the right atrium, resulting in perforation upon device excision. After device removal, a pericardial patch was sewn onto the defect. The operation was completed with no complications, and the patient had an uneventful postoperative recovery with a normal echocardiogram on discharge.