Causes & Risk Factors
Aqueductal web
An aqueductal web is a thin membrane within the cerebral aqueduct that can obstruct CSF flow and cause hydrocephalus.
In short: Aqueductal web
- It is a thin membrane partially or fully blocking the aqueduct.
- It is one form of aqueductal obstruction.
- It produces a triventricular pattern of enlarged ventricles.
- It is often well suited to treatment with ETV.
What it is
An aqueductal web is a thin membrane that forms within the cerebral aqueduct, partially or completely obstructing the flow of CSF through this narrow channel. It is one of the specific causes of aqueductal obstruction.
Understanding Aqueductal web
Like other forms of aqueductal narrowing, an aqueductal web blocks CSF flow between the third and fourth ventricles, causing the lateral and third ventricles to enlarge (the triventricular pattern) while the fourth stays normal. Because the obstruction is a discrete membrane at the aqueduct, this situation is often well suited to endoscopic third ventriculostomy (ETV), which creates a new outlet to bypass the blockage. Imaging, sometimes including CSF flow studies, helps identify the web and confirm the level of obstruction.
Why it matters
Understanding aqueductal webs helps families see how a thin membrane in a critical channel can cause hydrocephalus, and why this type of discrete blockage is often treatable by bypassing it with ETV.
Common questions
What is an aqueductal web?
A thin membrane obstructing the cerebral aqueduct.
What pattern does it cause?
A triventricular pattern of enlarged ventricles.
How is it often treated?
Frequently with ETV, which bypasses the blockage.
Bottom line
An aqueductal web is a thin membrane blocking the cerebral aqueduct, causing hydrocephalus often treatable with ETV.
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