Off-pump mitral valved stent implantation: A 3D-transesophageal echocardiographic based comparison of apical and sub-annular fixation techniques - Pokorny, S.; Huenges, K.; Bähr, T.; Bax, L.; Marczynski-Bühlow, M.; Morlock, M.M.; Cremer, J.; Lutter, G. (The Thoracic and Cardiovascular Surgeon, 2014)