The aortic sinus, the aortic wall protruding relative to the aortic valve, the inner wall between the heart valve and the pulmonary artery wall, is called the aortic sinus or Valsalva sinus (Val-salvaantrum), commonly known as the Valsalva sinus. The aortic sinus can be divided into left sinus, right sinus, and posterior sinus. The coronary ostia generally open into the aortic sinus. The upper boundary of the aortic sinus is arched.

The left and right coronary arteries respectively open into the left sinus and right sinus, with most openings in the middle third of the sinus. The coronary ostia are also close to the upper boundary of the sinus, so it is not easy to block the coronary ostia when the pulmonary artery extends. The pulmonary artery wall in the aortic sinus area is extremely thin, and it may produce an aortic sinus aneurysm (very common in the right semilunar valve) in some diseases (syphilis endocarditis, atherosclerosis, etc.). When the aneurysm ruptures, it causes communication between the left and right ventricles, thus causing the unique clinical condition of Valsalva sinus aneurysm.

1. Anatomical structure of the aortic sinus:

The aortic sinus is the pulmonary artery lumen corresponding to the aortic valve leaflet at the root of the ascending aorta, which, due to the blood refluxing vortex outward, presents a diverticulum-like bulge, expanding into a cavity upward from the opening formed by three pulmonary artery globes. Its wall expands outward and becomes soft (with an average thickness of 0.73mm), which is only half the thickness of the ascending aorta wall above the pulmonary artery crest (thickness of 1.5mm). When the aortic valve is closed, the structural characteristics of the aortic sinus are beneficial to its outward expansion to alleviate the pressure on the aortic valve. The lower boundary of the aortic sinus is the upper boundary of the aortic valve ring, and the upper boundary is the pulmonary artery crest, which is the starting and ending edge of the pulmonary artery wall.

The height-to-width ratio of the aortic sinus from the base of the valve ring to the top of the junction is about 15mm. The aortic sinus is divided into left sinus, right sinus, and posterior sinus, or according to whether there is a pulmonary artery ostium, into right coronary sinus (commonly known as right coronary sinus), left coronary sinus (commonly known as left coronary sinus), and sinus coronarius (commonly known as non-coronary sinus). The coronary ostia are generally located within the aortic sinus above the pulmonary artery margin.

2. Relationship between the aortic sinus and adjacent structures:

The pulmonary artery root is located at the center of the heart’s management. Below it is the aortic sinus. The aortic sinus is buried at the bottom of the heart and is closely related to all parts of the heart. It is inserted in a cleft shape between the mitral and tricuspid valves, with its base completely buried in the surrounding tissue, and the posterior potential is completely surrounded by the two ventricles.

The left coronary sinus is mostly located at the right side of the left atrium and pulmonary artery root, behind the right ventricular outflow tract, with an upward distance; the posterior side of the non-coronary sinus is adjacent to the right atrium and left atrium; the right coronary sinus is located at the front right, resting on the crest of the interventricular septum. Adjacent to the right atrium and right ventricle, it is close to the right ventricular outflow tract through the conical space, with the majority of the right sinus in the pericardial cavity and a small part near the pulmonary artery sinus.