Table 2.

Main challenges of stentless and sutureless VIV-TAVI procedures.

Stentless VIV-TAVI procedures
Features	Procedural complications
• Lack of radiographic and anatomic landmarks • Anchor on the non-compliant Dacron ring • Absence of calcifications due to predominant leaflet prolapse and severe aortic regurgitation as failure mechanism • Subcoronary implantation of stentless prosthesis is associated to shorter linear distance between the nadir of the stentless valve leaflets and the coronary arteries, as well as a shorter VTC distance	• Higher risk of device malposition, a second THV, paravalvular leak • Higher risk of coronary occlusion
Stentless VIV-TAVI procedures
Features	Procedural complications
• Elastic structure of the sutureless valve • Absence of sutures • An upper ring is located at the level of the decalcified annulus, while the lower segment of the valve protrudes in the left ventricular outflow tract for about 5 mm	• Valvular instability and dislocation when a THV is implanted inside • An incomplete expansion of the THV prosthesis implanted too low