Key Points
- To evaluate the anatomical features of the left atrial appendage and its spatial relationships to neighboring cardiovascular structures vulnerable to damage during appendage closure.
- Grossly examined 31 heart specimens, processed 4 left atrial appendages for histological sectioning, and generated endocasts from 11 appendages.
- Measured left atrial appendage orifice dimensions, distances to the left superior pulmonary vein, mitral valve, and coronary arteries, and documented nearby areas of wall thinning.
- The left atrial appendage orifice was oval in all specimens, displaying a mean (SD) diameter of 17.4 (4) mm (range 10–24.1 mm).
- Mean (SD) distances from the orifice were 11.1 (4.1) mm to the left superior pulmonary vein and 10.7 (2.4) mm to the mitral valve, with adjacent coronary arteries situated in close proximity.
- Thin atrial walls with pits or troughs appeared within a 20.9 mm radius of the orifice in 57.7% of hearts, with histology demonstrating small crevices and marked wall thinning.
Structured PICO
PPopulation31 heart specimens
IInterventionGross anatomical examination, histological examination (n=4), and endocasts (n=11)
OOutcomeAnatomical measurements of the LAA os diameter and proximity to the left superior pulmonary vein, mitral valve, and left anterior descending arterysurrogate
The LAA orifice is oval-shaped and in close proximity to critical structures like the left superior pulmonary vein, mitral valve, and anterior descending coronary artery, which may be at risk during LAA occlusion procedures.