aortic hiatus

The aortic hiatus is one of the three major apertures through the diaphragm and lies at the level of T12. Strictly speaking, it is not a real aperture in the diaphragm, but an osseoaponeurotic opening between it and the vertebral column.

The hiatus is situated slightly to the left of the midline and is bounded anteriorly by the crura and posteriorly by L1.

A number of structures pass through the aortic hiatus:

The vertebral levels of the 3 main diaphragmatic apertures can be remembered by this mnemonic.