Atrial dissections and pseudoaneurysms are rare complications of cardiac surgery. The authors describe the case of a patient after mitral valve replacement who presented with a left atrial appendage pseudoaneurysm. This case represents the first known closure of an atrial pseudoaneurysm with a percutaneous septal occluder device.
Atrial dissections and pseudoaneurysms are rare complications of cardiac surgery. There are few reported cases of such complications in the literature, with most of them revealing themselves within days to weeks of the original surgery and requiring open cardiac repair. We describe the case of a patient after mitral valve replacement who presented nearly 2 months after surgery with a left atrial appendage (LAA) pseudoaneurysm. Moreover, this case represents the first known closure of a pseudoaneurysm with a percutaneous septal occluder device, usually reserved for patent foramen ovale and atrial septal defects.
Case Presentation
A 53-year-old male with end-stage renal disease presented to the hospital for left knee pain and was diagnosed with villonodular synovitis. Following knee surgery, he became tachycardic and dyspneic, and cardiology was consulted. Transthoracic echocardiography and cardiac magnetic resonance imaging were performed and revealed a vegetation of the anterior leaflet of the mitral valve. Multiple blood cultures were drawn, which remained negative throughout the hospitalization. Because of the severity of the endocarditis, the patient underwent mitral valve replacement with a Medtronic 29-mm Mosaic bioprosthetic valve (Medtronic, Inc, Minneapolis, MN). The native mitral valve was sent to microbiology and all cultures, including fungal, acid-fast bacillus, and bacterial, were negative. Pathology revealed severe necrotizing endocarditis, with purulent inflammation. After a complicated postsurgical course, including ventilator-associated pneumonia and transient sinus node dysfunction with paroxysmal atrial fibrillation, the patient was discharged home 1 month after his initial knee surgery.
Approximately 2 months later, the patient returned to the hospital because of worsening dyspnea. His blood pressure was initially low but responded to normal saline boluses. Cardiology performed transthoracic echocardiography, which demonstrated a large cavity adjacent to the left ventricle suggestive of an LAA pseudoaneurysm ( Figure 1 ) with bidirectional flow across the defect ( Figure 2 ). Cardiac magnetic resonance imaging was done to confirm and visualize the pseudoaneurysm in greater detail. The pseudoaneurysm measured 9.1 × 3.7 cm, and the ostium of the defect measured 1.3 cm. On both imaging modalities, it was also clear that flow was bidirectional across the neck of the pseudoaneurysm.
After considering the risks involved with an open cardiac procedure due to the patient’s thrombocytopenia, renal failure, and hypercoaguable state (heparin-induced thrombocytopenia), it was decided that the defect would be repaired percutaneously. An Amplatzer septal occluder (AGA Medical Corporation, Plymouth, MN) was chosen to repair the defect. After obtaining informed consent from the patient, he was brought to the hybrid cardiac catheterization room. Vascular access was obtained, and a transseptal needle and sheath were used to perform a transseptal puncture across the interatrial septum. After successfully crossing the septum, a diagnostic catheter was advanced to the level of the LAA, and contrast was injected through the catheter to identify the LAA and defect. After careful review of images, a 14-mm Amplatzer septal occluder was chosen to close the pseudoaneurysm and was advanced to the defect ( Figure 3 ). Once appropriate positioning was confirmed by transesophageal echocardiography and fluoroscopy, the device was deployed and released ( Figure 4 ). Transesophageal echocardiography revealed only mild residual flow through the center of the device after release. Furthermore, echocardiographic “smoke” was visualized in the pseudoaneurysm, suggestive of a dramatic decrease in blood flow.
