part of 83 ISSN 1755-5302 Interv. Cardiol. (2014) 6(1), 83–93 10.2217/ICA.13.92 © 2014 Future Medicine Ltd REV IEW Transcatheter aortic valve replacement has been available to treat aortic valve disease for just over a decade and in that time, its use has expanded rapidly around the world. All transcatheter aortic valve replacement procedures depend on having safe remote access to the aortic valve. If femoral access is not feasible or safe, nonfemoral access routes are imperative. This article will discuss the commonly used nonfemoral access routes and how they are achieved. KEYWORDS: direct aortic access n subclavian/axillary access n transapical access n transcatheter aortic valve replacement Basel Ramlawi 1 & Michael J Reardon* 1 1 Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, TX, USA *Author for correspondence: Tel.: +1 713 441 5200 mreardon@houstonmethodist.org Symptomatic severe aortic stenosis (AS) carries a high mortality rate if not treated. This has led to the inclusion of a class I recommendation for sur- gical aortic valve replacement (AVR) in the Ameri- can College of Cardiology/American Heart Asso- ciation guidelines for patients with symptomatic severe AS. For over 60 years, AVR has served as the treatment of choice for AS and has saved countless lives. Unfortunately, there exists a population of patients whose age or co-morbidities makes them either an extreme risk or a high risk for open AVR. This represents between 30 and 60% of the patients with symptomatic severe AS, who are as a result denied surgical intervention. This popula- tion increases with increasing age and will become a larger burden in the future. Transcatheter AVR (TAVR) has been developed as an alternative treat- ment to surgical AVR in the extreme-risk and high-risk population who are deemed inoperable or too risky to operate on. The TAVR procedure enables AVR without performing open heart sur- gery and cardiopulmonary bypass. The procedure involves implantation of a prosthetic heart valve within the diseased native aortic valve through a minimally invasive approach. TAVR valve systems consist of a frame to hold the valve and to help push the native stenotic aortic valve leaflets out of the way, along with the valve itself and the delivery system. The TAVR proce- dure consists of delivering a device into the stenotic aortic valve, expanding the frame of the device, deploying the valve and removing the delivery sys- tem. The sine qua non of TAVR is a safe remote access to the heart and aortic annulus. TAVR approaches It is generally accepted that a transfemoral approach is the least invasive alternative and should be used whenever possible. Although refinements of the delivery systems are leading to development of smaller systems, the currently available transfemoral delivery systems in the USA range from 18 to 24 F, requiring minimal arterial luminal diameters of 6–8 mm. Push- ing beyond the safe limits for femoral sheath and device delivery can lead to serious vascular complications and death. To avoid such vascular disasters, nonfemoral alternative access routes for TAVR have been developed and will be the subject of this paper. The ordering of the access routes discussed below is based on the current order of preference of the nonfemoral access approaches at the Houston Methodist DeBakey Heart and Vascular Center (TX, USA). n Subclavian artery access Subclavian artery access was developed for use with the Medtronic CoreValve (Medtronic Inc., MN, USA) and its 18 F delivery system. Major- ity of the experience gained so far is with this valve. With the availability of the Sapien XT (Edwards Lifesciences Corporation, CA, USA) with an 18 F delivery system, subclavian access with Sapien XT has also been carried out. A minimum luminal diameter of 6 mm in an uncalcified artery is necessary for safe subclavian access and increases to 7 mm in an artery with significant calcification. For implantation of the CoreValve from the left subclavian, the angle of the aorta from the horizontal should not exceed 70° and from the right subclavian, it should not exceed 30°. Angles beyond these make axial alignment and proper placement of the valve increasingly difficult. In marginal arteries, the CoreValve can be placed bareback without the sheath. With the proximity to the annulus, this No ntra nsfe mo ra l a c c e ss a lte rna tive s fo r tra nsc a the te r a o rtic va lve re p la c e me nt