The progression of an infundibulum to aneurysm formation and rupture: case report and literature review

Neurosurgery. 1998 Dec;43(6):1445-8; discussion 1448-9. doi: 10.1097/00006123-199812000-00107.


Objective and importance: Infundibula (IFs) are funnel-shaped symmetrical enlargements that occur at the origins of cerebral arteries and are apparent on 7 to 25% of otherwise normal angiograms. They are frequently considered as normal anatomic variants of no pathogenic significance.

Clinical presentation: We report the case of a ruptured posterior communicating artery aneurysm that had developed at the site of a previously known IF in a 49-year-old hypertensive woman. She had a poor conscious level at admission, with widespread subarachnoid hemorrhage and obstructive hydrocephalus.

Intervention: The patient was immediately ventilated, and an external ventricular drain was inserted. The aneurysm was successfully clipped; however, secondary hemorrhage occurred both before and during craniotomy. She developed marked hypernatremia and subsequently died.

Conclusion: This is the 11th case of IF-to-aneurysm progression reported. It suggests that in certain cases, serial investigations may be indicated with IFs to detect aneurysm formation and preempt rupture.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Aneurysm, Ruptured / pathology*
  • Carotid Arteries / pathology
  • Cerebral Arteries / anatomy & histology
  • Cerebral Arteries / pathology*
  • Craniotomy
  • Disease Progression
  • Drainage
  • Fatal Outcome
  • Female
  • Humans
  • Hydrocephalus / etiology
  • Hydrocephalus / surgery
  • Hypernatremia / etiology
  • Hypertension / complications
  • Intracranial Aneurysm / pathology*
  • Intracranial Aneurysm / surgery
  • Middle Aged
  • Recurrence
  • Rupture, Spontaneous
  • Subarachnoid Hemorrhage / etiology