Table 1.

Steps, advantanges and diadvantages of the stenting techniques during coronary protection in VIV-TAVI procedures.

Chimney Snorkel Stenting Technique	Orthotopic Snorkel Stenting Technique
Technique Description	Technique Description
• Guiding catheter, wire(s) and stent are positioned in coronary artery prior to percutaneous balloon aortic valvuloplasty or THV deployment	• Guiding catheter, wire(s) and stent are positioned in coronary artery prior to percutaneous balloon aortic valvuloplasty or THV deployment
• The stent length selection: the stent comes above the height of the pre-existing bioprosthesis in situ (with enough stent in the proximal port of the coronary artery to allow for adequate anchoring) and above the most superior portion of the THV bioprosthesis leaflet or commissural attachment point	• The baseline stent length is selected according to chimney/snorkel stenting technique
• Eventual THV post-dilatation is performed prior to coronary artery stents deployment	• Eventual THV post-dilatation is performed prior to coronary stent decision
• Coronary stent is deployed with a substantial portion of the stent hanging into the aorta and ideally at least enough to come above the highest tract of the sealed portion of the THV	• After the prosthesis implantation and eventual post-dilatation, if coronary is not completely occluded, a second guiding catheter is advanced into the THV to reach the coronary ostium thought the prosthesis frames and the coronary artery is wired.
• Stent balloon pulled back away from the distal edge is inflated to higher pressures for flaring the proximal stent improving chance of re-access	• The stent is advanced and positioned from the coronary artery to the THV prosthesis with minimal protrusion inside the frame
• A kissing technique with simultaneous inflation of the THV balloon and the coronary stent balloon can be performed but is not mandatory	• Stent balloon pulled back away from the distal edge is inflated to higher pressures for flaring the proximal stent improving chance of re-access
Technique advantages	Technique advantages
• Quickly coronary flow restoration withdrawing and deploying the coronary stent in case of coronary occlusion	• A physiologic THV frame/coronary stent configuration with reduced external stent compression risk and facilitate coronary recannulation
Technique disadvantages	Technique disadvantages
• No physiological and very complex THV frame/stent configuration with possible coronary stent compression	Higher technical complexity and increased procedural time
Repeated coronary angiography or interventions may be more difficult	• The THV prosthesis orientation influences the procedure