Complications of aortic valve surgery: Manifestations at CT and MR imaging

Aortic valve replacement accounts for a significant portion of cardiac surgeries in the United States. Despite advances in prosthetic heart valve design, surgical technique, and postoperative care, complications after aortic valve replacement remain a leading cause of morbidity and mortality. Routine surveillance of prosthetic heart valves with transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and fluoroscopy is important, as these techniques allow accurate detection of prosthetic valve dysfunction. However, echocardiography and fluoroscopy may not allow identification of the specific underlying cause, including paravalvular leak, dehiscence, endocarditis, obstruction, structural failure, pseudoaneurysm formation, aortic dissection, and hemolysis. Magnetic resonance (MR) imaging and computed tomography (CT) have an emerging role as diagnostic tools complementary to conventional imaging for detection and monitoring of complications after aortic valve replacement. The choice between CT and MR imaging depends on individual patient characteristics, the type of prosthetic valve, and the acuity of the clinical situation. In general, screening with TTE followed by TEE is recommended. When results of TTE and TEE are inconclusive, cardiac CT and MR imaging should be considered. The choice between these imaging techniques depends on the presence of patient-specific contraindications to CT or MR imaging.