sigmoid sinus

The sigmoid sinus is more vulnerable to injury.

Bleeding from the sigmoid sinus can be difficult to control and can significantly increase operative blood loss.

The middle and posterior fossa dura are identified as well as the sigmoid sinus.

Note that a superior petrosal sinus enters the junction of the transverse and sigmoid sinuses.

Also an inferior petrosal sinus enters the sigmoid sinus near the jugular foramen.

A high jugular bulb or anteriorly placed sigmoid sinus can substantially compromise the space available for tumor removal.

The bone is removed from these structures to allow retraction of the temporal lobe dura and sigmoid sinus.

Blood from the brain and neck flows from: (1) within the cranium via the internal jugular veins, a continuation of the sigmoid sinuses.

If a dominant sigmoid sinus is occluded during the operation, postoperative intracranial pressure elevation or venous infarct can occur.

Condylar emissary vein is a vein connecting the suboccipital plexus of veins with the sigmoid sinus.

The sigmoid sinus, which continues the transverse sinus, empties into the jugular vein at the jugular foramen.

The internal jugular vein is formed by the anastomosis of blood from the sigmoid sinus of the dura mater and the common facial vein.

Computed tomography shows a multilocular, lytic destructive temporal bone mass, centered within the endolymphatic sac (between internal auditory canal and sigmoid sinus).

The cavernous sinus drains by two channels, the superior and inferior petrosal sinuses, ultimately into the internal jugular vein via the sigmoid sinus.

The sigmoid sinuses (left & right), within the human head, are two areas beneath the brain which allow blood to drain inferiorly from the posterior center of the head.

On both sides and at the base of the brain, the inferior petrosal sinus and the sigmoid sinus do not join to form the internal jugular vein.

The posterior transmits the sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries.

They drain from the confluence of sinuses (by the internal occipital protuberance) to the sigmoid sinuses, which ultimately connect to the internal jugular vein.

It transmits a Mastoid emissary vein to the sigmoid sinus and a small branch of the occipital artery, the posterior meningeal artery to the dura mater.

Anteriorly placed sigmoid sinus: In such circumstances, the distance between the sigmoid sinus and the external auditory canal may be a few millimeters or less.

Through the condylar canal, the occipital emissary vein connects to the venous system including the suboccipital venous plexus, occipital sinus and sigmoid sinus.

Griesinger's sign: Erythema and edema over the mastoid process due to septic thrombosis of the mastoid emissary vein and thrombophlebitis of the sigmoid sinus.

Each sigmoid sinus begins beneath the temporal bone and follows a tortuous course to the jugular foramen, at which point the sinus becomes continuous with the internal jugular vein.

From here, two transverse sinuses bifurcate and travel laterally and inferiorly in an S-shaped curve that form the sigmoid sinuses which go on to form the two jugular veins.

These pass along the articulation between the posterior edge of the petrous temporal and the anterior edge of the occipital bones to the jugular foramen where the sigmoid sinus becomes the internal jugular vein.