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Page 4 of 11 Avvedimento et al. Mini-invasive Surg 2022;6:24 https://dx.doi.org/10.20517/2574-1225.2021.143

Among the most important factors influencing coronary re-access with the use of a self-expanding valve, we
have to include implantation depth. Recently, an implantation depth of at least 4 mm below the annular
plane has been advised to avoid an overlaying between the skirt, theoretically designed to prevent
paravalvular regurgitation, and coronary arteries.

Yudi et al. proposed an algorithm to guide interventional cardiologists in the engagement of coronary
[13]
ostia after TAVI, advising the use of a smaller catheter for the left coronary artery (JL 3.5 and JL 3 for
femoral and radial access) or the Ikari right guide catheter for self-expanding THVs, without significant
technical changes in the presence of balloon-expandable valves.

Strong efforts should be directed toward valve selection and commissural alignment to achieve more
anatomic valve implantation and better preserve coronary access. Careful consideration should be reserved
to patients with low coronary height at the time of valve selection and implantation, not only to avoid
dreadful complications, such as acute coronary occlusion, but also to allow easy coronary re-engagement,
specifically important in the management of eventual acute coronary syndrome when rapid
revascularization is crucial.

Redo-TAVI
In the last few years, given the likelihood of structural valve deterioration and non-structural valve
dysfunction after index TAVI, redo-TAVI has emerged as a therapeutic alternative to TAVR-explant in
anatomically suitable patients . Better outcomes over time for redo-TAVI have been mainly driven by
[14]
improved patient selection and procedural techniques leading to a lower rate of valve malpositioning and
coronary obstruction. However, redo-TAVI carries a non-negligible risk of acute coronary obstruction
[3.5% reported in Valve-in-Valve International Data (VIVID) registry], differently from redo-SAVR, where
commissural alignment between surgical and native valve is easily obtained. Moreover, the vertical
displacement of the first THV after redo-TAVI, in addition to the native aortic valve leaflets, makes
coronary access after redo-TAVI even more challenging due to the risk of sinus of Valsalva sequestration .
[15]
This complication occurs more frequently with self-expandable THVs, as demonstrated in RESOLVE
registry where Evolut R/Evolut PRO platforms carried a significantly higher risk of sinus sequestration
compared to the SAPIEN 3 valve (45.5% vs. 2.0%; P < 0.001, respectively) because of Evolut’s supra-annular
[17]
leaflets and tall commissural height . Tarantini et al. proposed an algorithm on TAVI vs. SAVR at the
[16]
index aortic valve intervention based on the STJ anatomy to evaluate the risk of coronary re-access after
redo-TAVI. Anatomical, device, and procedural factors affecting coronary access after redo-TAVI in
prostheses with a sub-coronary or supra-coronary risk plane are provided in Figure 2. Tall-frame THV have
higher asymmetric commissures, as shown in Figure 3, thus making the use of low-frame THV
advantageous for redo-TAVI.

Commissural alignment is also of the utmost importance during initial TAVI as misalignment makes any
leaflet management strategy such as BALISICA (bioprosthetic or native aortic scallop intentional laceration
to prevent iatrogenic coronary artery obstruction) difficult or unfeasible. This technique has been
successfully applied in TAVI-in-SAVR procedures, but its use in TAVI-in-TAVI is possible only when
[18]
commissures of the first THVs are aligned with the natives . Moreover, in the setting of TAVI-in-TAVI
other protective strategies, such as chimney stenting (preemptive positioning of stent and deployment in
obstructive coronary ostium), may not be useful because the stent frames in the aortic root are covered by
first TAVI leaflets.