The aortic valve: integrated gross, microstructural, and cellular anatomy

OBJECTIVES: To synthesise current knowledge of the normal human aortic valve by integrating its gross anatomy, microarchitecture, and cellular biology within a unified anatomical framework. This review aims to bridge traditionally separate descriptions of macroscopic, histological, and biological structure and highlight their relevance to valve function and contemporary clinical practice. METHODS: A narrative review of the literature was undertaken, examining the macrostructural anatomy of the aortic valve and root, leaflet microarchitecture, extracellular matrix organisation, and the cellular biology of valvular endothelial and interstitial cells. Emphasis was placed on anatomical terminology, three-dimensional geometry, and the functional relationships between structure across multiple spatial scales. RESULTS: The competence and durability of the aortic valve depend on coordinated interactions between root geometry, leaflet architecture, extracellular matrix composition, and cellular regulation. The functional interplay between the leaflets, interleaflet triangles, annulus, and sinuses of Valsalva maintains valve competence, while the conserved trilaminar leaflet structure provides region-specific mechanical properties. Valvular endothelial and interstitial cells regulate matrix homeostasis and adaptive remodelling, linking normal physiology with mechanisms underlying valve degeneration and disease. CONCLUSIONS: Viewing the aortic valve as an integrated, multiscale biological system provides a more comprehensive understanding than isolated anatomical or histological descriptions. This framework has direct relevance to valve-sparing surgery, transcatheter interventions, and the development of tissue-engineered valve substitutes, providing an anatomical basis for understanding normal valve function, pathological change, and future therapeutic innovation.