Use of imaging for procedural guidance during transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has recently emerged as an alternative to surgical aortic valve replacement for patients with severe, symptomatic aortic stenosis who are at a 'high risk' or deemed inoperable. Multiple imaging modalities are integral to procedural success and recent studies may help establish the role of each modality.

Procedural guidance includes preimplantation device selection, intraprocedural guidance of valve positioning and post-implantation assessment of procedural success. Numerous studies have suggested that three-dimensional (3D) assessment of the aortic annulus and adjacent structures by multislice computed tomography (MSCT) or cardiac MRI can improve annular sizing and reduce complications. Subsequent studies suggest that 3D transesophageal echocardiography (TEE) can also accurately measure the annular aortic annulus. New imaging techniques help with coaxial fluoroscopic positioning. Finally, the use of intraprocedural TEE allows imaging of complications.

Multimodality imaging is indispensable for procedural guidance during TAVR. MSCT is a fundamental part of preprocedural planning, including the assessment of peripheral vasculature, the aortic root and the annulus and optimal fluoroscopic positioning. Echocardiography, particularly two-dimensional (2D) and 3D TEE, is an integral part of preprocedural, intraprocedural and immediate postprocedural assessment. MRI remains at this time an adjunctive imaging modality for procedural guidance, but may have an essential role in postprocedural valve assessment.