aortic annulus
Pronunciation: an-YU-lus
Fibrous ring at the base of the aorta where the aortic valve leaflets attach; critical for valve sizing and function.
Full Definition
The fibrous tissue ring that forms the base of the aortic valve, serving as the attachment point for the three aortic valve cusps. The annulus provides structural support and maintains the valve's circular geometry essential for proper function. During aortic valve replacement, accurate measurement of the annulus diameter is crucial for selecting appropriately sized prosthetic valves. Annular calcification or dilatation can complicate valve replacement and may require annular reconstruction or enlargement procedures.
Usage
Usage note: Critical structure for valve replacement; accurate sizing prevents patient-prosthesis mismatch.
In Context
- "The calcified aortic annulus required extensive debridement before valve implantation." — operative note
- "Annular sizing revealed a 23mm diameter suitable for the prosthetic valve." — valve replacement procedure