Membranous septum length and bicuspid aortic valve
The current study demonstrated similar MS length in BAV and TAV
patients, unlike the previous study that revealed shorter MS length in
BAV than TAV (24 ). A possible explanation for this discrepancy
is the difference in measuring the MS length (18, 24 ). We
speculate that it is more difficult to control the deployment of the THV
due to challenging anatomical features accompanied with BAV such as
eccentric device landing zone calcification, asymmetric geometry of the
cusps, and concomitant pathologies of the aorta (severe tortuosity,
horizontal aorta, and aneurysms) (31 ). Thus, the implantation
might be targeted deeper to avoid valve migration or embolization rather
than high implantation when the device manipulation is difficult
especially in a trans-femoral case. Also, variation of implantation
depth was higher in the BAV group (0.59 vs 0.34), which might reflect
the unstable control of implantation depth compared to TAV. Further
studies demonstrating the relation between implantation depth and the
safety or the efficacy of high implantation for BAV are warranted.