Types of and Location of
Cerebral aneurysms are classified
both by size and shape.
- Small aneurysms have a diameter of less
than 15 mm.
- Larger aneurysms include those classified
as large (15 to 25 mm.), giant (25 to 50 mm.), and super
giant (over 50 mm.)
- Saccular aneurysm refers to any
aneurysm with a saccular outpouching including berry aneurysms. Saccular
aneurysms are the most common form of cerebral aneurysm.
- Berry aneurysm, is a type of saccular aneurysm with
a neck or stem resembling a berry.
- A fusiform aneurysm describes an aneurysm
without a stem.
Cerebral aneurysms usually occur at the
bifurcations and branches of the large arteries located at the
Circle of Willis. Approximately 85% of aneurysms develop in the
anterior part of the circle of Willis, and involve the internal
carotid arteries and their major branches that supply the
anterior and middle sections of the brain.
The most common sites include the:
- Anterior Communicating artery (30 - 35%)
- Bifurcation of the Internal Carotid and
Posterior Communicating artery (30 - 35%)
- Bifurcation of Middle cerebral (20%)
- Basilar artery bifurcation (5%)
- Remaining posterior circulation arteries (5%)
majority of cerebral aneurysms occur in the anterior portion of the Circle
Homepage | Course
catalog | Discount
prices | Login | Nursing
jobs | Help
Interactive, LLC all rights reserved