Review of alternative access in transcatheter aortic valve replacement

Aortic stenosis is a progressive condition with a poor prognosis and no medical treatment options and ultimately requires valve replacement. Over the past decade, the development of transcatheter aortic valve replacement (TAVR) has provided an option for patients at high- and extreme-risk for surgical aortic valve replacement (SAVR). TAVR has also been approved by the Food and Drug Administration (FDA) in the intermediate risk population based on favorable clinical trial data, and recently, TAVR has been shown to be superior or non-inferior to SAVR even in patients at low risk for SAVR (1,2). TAVR volume now exceeds the volume of SAVR in the treatment of aortic stenosis in the United States (3). The majority of TAVR procedures (92 percent) in the Unites States are performed via the preferred transfemoral approach (4). In addition, the majority of patients included in the Medtronic Corevalve and Edwards Sapien high and intermediate risk trials received TAVR via a transfemoral approach (5-8). and alternative access cases were excluded in the low risk trials (1,2). However, approximately 25% of patients undergoing TAVR have significant peripheral arterial disease which has been linked to increased procedural complications and worsened clinical outcomes at 1-year (9). With this in mind, pre-procedural planning with gated cardiac computed tomography (CT) is essential to select an appropriate access site prior to the procedure. Early in the TAVR experience, the only alternative access was transapical access, which has consistently been linked to increased morbidity and procedural complications (10-13). Over the past several years several centers have published data demonstrating the safety of alternative access through transaxillary, transcarotid, transcaval, and direct aortic access. These approaches have now supplanted apical access. In 2013, transapical access peaked occurring in over 40% of the TAVR cases in the United States (14). However, with smaller delivery sheaths and availability of alternative approaches the rate of transapical access or direct aortic access in the United States was only 4.8% from 2015 to 2017 and has continued to decline (4,14). In 2017, axillary access surpassed apical or direct aortic access as the most common alternative access strategy in the United States, although there is still limited utilization of carotid access (14). This review will describe the available data on alternative access and our approach to pre-procedural planning, access site selection, and peri-procedural techniques