Internal carotid aplasia/hypoplasia and intracranial saccular aneurysms: series of three new cases and systematic review of the literature

J Neuroimaging. 2007 Apr;17(2):141-7. doi: 10.1111/j.1552-6569.2007.00092.x.


Background and purpose: Abnormal arterial flow dynamics and intracranial collateral pathways can be seen in patients with congenital internal carotid artery (ICA) aplasia or hypoplasia. Here we seek to evaluate whether ICA aplasia/hypoplasia is associated with an increased prevalence of intracranial saccular aneurysm relative to carotid rete mirabile.

Methods: We combined our experience of three cases with 148 previous publications to form a retrospective series including 132 cases of ICA aplasia, 33 cases of ICA hypoplasia, and 34 cases of carotid rete mirabile.

Results: After excluding cases lacking angiograms, ICA aplasia/hypoplasia was more commonly associated with aneurysm (45/158, 27.8%) compared with rete mirabile (2/34, 5.9%). A significantly greater overall aneurysm prevalence was seen among ICA aplasia/hypoplasia patients age 30 years or older (38/101, 36.6%) than in younger individuals (7/48, 14.6%).

Conclusions: Intracranial saccular aneurysm is more strongly associated with ICA aplasia/hypoplasia than rete mirabile. An increased aneurysm prevalence among older individuals with ICA aplasia/hypoplasia suggests an acquired etiology. Magnetic resonance angiography (MRA) is recommended in the initial evaluation of ICA aplasia/hypoplasia to evaluate for intracranial saccular aneurysm, particularly after the third decade of life.

Publication types

  • Case Reports
  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Angiography, Digital Subtraction
  • Arteriovenous Malformations / diagnosis*
  • Carotid Artery Diseases / congenital
  • Carotid Artery Diseases / diagnosis*
  • Carotid Artery Diseases / therapy
  • Carotid Artery, Internal / abnormalities*
  • Carotid Artery, Internal / pathology
  • Female
  • Humans
  • Infant
  • Intracranial Aneurysm / diagnosis*
  • Intracranial Aneurysm / therapy
  • Magnetic Resonance Angiography
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Tomography, X-Ray Computed
  • Ultrasonography, Doppler, Duplex