Anterior intercavernous sinus
Sinus intercavernosus anterior
A small dural venous sinus crossing the midline in front of the pituitary gland, joining the two cavernous sinuses.
At a glance
- English
- Anterior intercavernous sinus
- Latin (TA2)
- Sinus intercavernosus anterior
- System
- Vein
- Region
- Head
- Side
- Single, on the midline
About the anterior intercavernous sinus
The anterior intercavernous sinus is a short venous channel within the dura mater on the body of the sphenoid bone. It runs from side to side across the midline in front of the hypophysis, the pituitary gland, in the forward margin of the diaphragma sellae, the dural sheet roofing the pituitary fossa. At each end it opens into a cavernous sinus, so it ties the right and left sinuses together.
It has a partner behind the gland, the posterior intercavernous sinus. Together with the two cavernous sinuses these cross channels make a ring of venous blood around the pituitary, known as the circular sinus. The anterior channel is usually the bigger of the pair, but there is wide variation: either one may be missing, and in some people the two are so extensive that the whole floor of the sella is lined with venous spaces.
Its role is to balance flow and pressure between the cavernous sinuses. Blood arriving on one side, from the ophthalmic veins or the sphenoparietal sinus, can cross to the other, and both sides drain on backwards through the petrosal sinuses. The hormones released by the pituitary also leave through veins that empty into this surrounding ring.
The sinus matters most in pituitary surgery. In the transsphenoidal route the surgeon opens the front wall of the sella through the sphenoid sinus, and the dura there may contain a large anterior intercavernous sinus. Cutting into it can cause brisk venous bleeding that hides the field, so its size is judged on imaging beforehand. Because the circular sinus links both sides, infection or clot in one cavernous sinus can also spread across to the other.
Course and drainage
- Begins at
- Arises from one cavernous sinus in front of the pituitary gland.
- Drains into
- Opens into the opposite cavernous sinus, completing the front of the circular sinus.
- Drains
- Links the two cavernous sinuses and drains veins around the front of the hypophysis.
Anthromica
See the anterior intercavernous sinus where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
