Page 95 - Read Online

Page 8 of 11 Avvedimento et al. Mini-invasive Surg 2022;6:24 https://dx.doi.org/10.20517/2574-1225.2021.143

oriented in the cusp overlap view for each of the three different self-expanding valves (Evolut R/PRO,
Acurate Neo2 and Portico) is provided in Figure 6.

Patient-specific commissural alignment of the self-expanding Evolut valve using the cusp overlap view has
also been described in 13 consecutive ViV procedures with successful valve implantation in all patients and
well-aligned commissures in 95% of cases at post-procedural CT scan .
[25]
Even though the evidence from these studies provides technique modifications to obtain commissural
alignment with available self-expanding TAVI devices, further improvements in THV and delivery system
design are ultimately needed.

Balloon-expandable THVs
Crimping one commissure at 3, 6, 9, or 12 o’clock can change initial deployment orientation for balloon-
expandable THV. Differently from self-expandable valves, no improvement in commissural alignment was
[20]
observed in the ALIGN TAVR study with different crimping of the SAPIEN 3 THV . This is usually less
impactful on future coronary re-access given the design of the SAPIEN 3 valve with low frame height and
large-cell frame. Diagnostic and therapeutic angiography can easily be performed cannulating coronary
ostia above the top of the stent frame. The unique challenging scenario is represented by cases in which
SAPIEN 3 protrudes above narrow STJ .
[16]
However, achieving commissural alignment can have a beneficial effect on long-term stress on prosthetic
leaflets, improving hemodynamics, including when a balloon-expandable valve is implanted. For these
reasons, a recent study has described a novel method of assessing commissural alignment for SAPIEN 3
based on pre-procedural 3D-CT and fluoroscopy in two views . Despite some limitations, this method
[26]
could be employed in larger studies to evaluate the impact of misalignment of valve durability and clinical
outcomes.

Mechanically expandable LOTUS THVs
Despite the increased awareness of the importance of future coronary re-access after TAVI, no data exist
about commissural alignment with mechanically expandable LOTUS valves. The cylindrical shape strongly
[27]
influences the interaction between THV flame and native STJ. Indeed, Moriyama et al. reported a high
rate of unfavorable coronary access (29.3% for LCA and 41.5% for RCA) with Lotus THV, mainly because
only two pathways, “above the THV flame” and “through outside of the THV flame”, were available for
achieving selective coronary cannulation after TAVI.

FUTURE DIRECTIONS
In contemporary TAVI practice, optimal valve selection and implantation techniques have achieved better
procedural outcomes. However, further efforts should aim to refine THVs design and delivery system to
make neo-commissural alignment easier and safer to facilitate the lifetime management of patients with
aortic valve and coronary artery disease [28,29] . Different principles should guide the design of future THVs:
(1) a leaflet posts position easily identified on fluoroscopy; (2) the possibility of an easy and safe rotation of
delivery system across the aortic valve reducing the risk of aortic damage; and (3) specific instructions to
align bioprosthetic valve commissures with the native provided by the manufactures. Available evidence
sheds light on the features of the ideal device to ensure optimal long-term outcomes in terms of valve
hemodynamic and durability, eventual future coronary access, and/or ViV procedures.