Novel apical-to-femoral rail technique for horizontal aorta in transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) has emerged as a viable treatment option for patients with severe aortic stenosis regardless of its surgical risk stratification (Otto et al., 2021). Aortic angulation is usually measured as the angle between the horizontal and the aortic annulus planes based on preproced‍ural multidetector computed tomography (MDCT) (Al-Lamee et al., 2011). Extremely horizontal aorta, defined as an aortic angulation greater than 70°, is an unfavorable anatomic structure that poses particular technical challenges for TAVR. Abramowitz et al. (2016) have proved that an extremely horizontal aorta increased the risk of procedural complications, such as lower device success rates, more moderate or even severe perivalvular leakage (PVL), and the need for second valve implantation. Because of the long stent frame, inflexibility, and non-steerability, it is challenging to pass the delivery system of self-expanding valves (SEVs) through an extremely horizontal aorta. As a result, patients with an extremely horizontal aorta have always been excluded from the clinical trials of TAVR, and transfemoral (TF)-TAVR with SEV is considered as an "off-label" use of TAVR (Adams et al., 2014; Kaneko et al., 2020). Herein, we present a technically difficult case, in which a patient with an extremely horizontal aorta underwent TF-TAVR with SEV by applying a unique apical-to-femoral rail strategy.