The spatial position of the RAV
The number of detected leaflets in the RAV was found to affect the
relative position of the valve components. The supero-septal commissure
was located on the septal side of the right atrium in proximity to the
apex of Koch’s triangle and its location was the most stable point
within the RAV circumference. Its position remained unchanged when
comparing the 3- and 4-leaflet heart valves (Table 1, p >
0.05). In all examined hearts, the supero-septal commissure was located
on the left-superior side of the ostium of the coronary sinus (Figure
1). The supero-septal commissure was never present within the vestibule
of the right atrial appendage. This contrasted with the location of the
supero-mural commissure which was always found in the vestibule’s middle
sector. We observed a strong positive correlation between the length of
the supero-septal commissure and the distance between the commissure and
the ostium of the coronary sinus (r = 0.51, p < 0.001). No
association was detected between the distance from the commissure to the
ostium of the coronary sinus and the septal leaflet length (r = 0.12, p
= 0.31).
The location of commissures found within the infero-mural aspect of the
RAV annulus (the muro-septal and the infero-septal commissures) varied
considerably, not only between different RAV configurations, but also
between individual hearts with the same number of RAV leaflets. In the
3-leaflet heart valves, the muro-septal commissure was located further
away from the ostium of the coronary sinus than the infero-septal
commissure in the 4-leaflet configuration (16.1 ± 9.0 vs. 7.7 ± 6.3 mm,
p < 0.001). The opposite trend was observed for the
commissure’s distance to the terminal crest (5.8 ± 9.4 vs. 13.5 ± 6.4
mm, respectively; Table 1, p < 0.001). The location of the
muro-septal commissure differed significantly: in 52.2% of specimens it
was located in the area of the cavo-tricuspid isthmus (situated between
the ostium of the coronary sinus and the terminal crest); in 9.0% of
hearts it was situated at the level or to the left of the ostium of the
coronary sinus; in 17.9% it was at the level of the terminal crest, and
in the remaining 20.9% of cases it was found within the vestibule of
the right atrial appendage (Figure 3). Additionally, there was a
positive correlation between the segment from the muro-septal commissure
to the terminal crest and the superior leaflet length (r = 0.32, p =
0.008). Meanwhile, this same segment had a negative correlation with
septal leaflet length (r = -0.38, p = 0.001).
In 4-leaflet RAVs, the infero-septal commissure was predominantly
located in the cavo-tricuspid isthmus area (81.8% of cases). It was
never located within the area of the vestibule of the right atrial
appendage. In the remaining 12.1% of hearts, the commissure was located
at the level of the ostium of the coronary sinus while in 6.1% of
cases, it pointed towards the septal direction. The spatial position of
the infero-septal commissure in the 4-leaflet valve was influenced by
the length of the septal leaflet (there was a positive correlation with
the commissure’s distance to the ostium of the coronary sinus [r =
0.51, p = 0.03] and a negative correlation with the commissure’s
distance to the terminal crest [r = -0.37, p = 0.03]). The
infero-mural commissure was always located within the area of the right
atrial appendage vestibule.
The relative positions of the components of the RAV were not affected by
the donors’ age, sex or any other anthropometric features (weight,
height, BMI).