Vessel
Confluence of sinuses
A variable junction of posterior dural venous channels
High-yield
The familiar diagram of three inflows joining two transverse sinuses is a starting model. Real confluences may be divided, asymmetrical or incompletely communicating.
Overview
Near the internal occipital protuberance, sagittal, straight, occipital and transverse sinus channels meet in arrangements collectively called the torcular or confluence. Some form a shared chamber; others remain partly separated by partitions or favor one outflow side. Superior sagittal flow often favors the right, but this is not universal.
Reference facts
- Origin
- Convergence of superior sagittal, straight and often occipital sinus channels in the posterior occipital dural region.
- Course
- A variable junction near the internal occipital protuberance and the posterior falx–tentorium attachments; it is not always one open chamber.
- Branches
- Principal contributing channels are the superior sagittal, straight and occipital sinuses, with variable continuity between them.
- Drains to
- Right and left transverse sinus pathways, which may differ in size and in the venous inflow they receive.
Clinical correlation
Normal small-caliber channels and uneven flow can resemble sinus obstruction on some venographic images. Interpretation considers the entire drainage pattern and acquisition method rather than diagnosing thrombosis from asymmetry alone.
Frequently asked questions
Where do the confluence of sinuses originate?
The confluence of sinuses arise from the convergence of superior sagittal, straight and often occipital sinus channels in the posterior occipital dural region.
Where do the confluence of sinuses drain to?
The confluence of sinuses drain to the right and left transverse sinus pathways, which may differ in size and in the venous inflow they receive.
What are the tributaries of the confluence of sinuses?
Principal contributing channels are the superior sagittal, straight and occipital sinuses, with variable continuity between them.
What is the course of the confluence of sinuses?
A variable junction near the internal occipital protuberance and the posterior falx–tentorium attachments; it is not always one open chamber.