Microneurosurgical management of aneurysms at the A2 segment of anterior cerebral artery (proximal pericallosal artery) and its frontobasal branches

Surg Neurol. 2008 Sep;70(3):232-46; discussion 246. doi: 10.1016/j.surneu.2008.03.008. Epub 2008 May 16.


Background: Aneurysms originating from the A2 segment of ACA and its frontobasal branches are rare, forming less than 1% of all IAs. There are only few reports on management of A2As. In this article, we review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of A2As.

Methods: This review, and the whole series on IAs, is mainly based on the personal microneurosurgical experience of the senior author (JH) in two Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland.

Results: These two centers have treated more than 10000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients and 4253 IAs, there were 35 patients carrying 35 A2As, forming 1% of all patients with IAs, 0.8% of all IAs, and 3% of all ACA aneurysms. Twenty-one (60%) patients presented with ruptured A2As with ICH in 11 (52%) and IVH in 7 (33%). Nineteen patients (54%) had multiple aneurysms.

Conclusions: A2As are often small, even when ruptured, with relatively wide base, and they are frequently associated with ICHs of IVHs. Our data suggest that A2As rupture at smaller size than IAs in general. The challenge is to select appropriate approach, locate the aneurysm deep inside the interhemispheric fissure, and to clip the neck adequately without obstructing branching arteries at the base. Unruptured A2As also need microneurosurgical clipping even when they are small.

Publication types

  • Review

MeSH terms

  • Anterior Cerebral Artery / diagnostic imaging
  • Anterior Cerebral Artery / pathology
  • Anterior Cerebral Artery / surgery*
  • Brain / blood supply
  • Brain / pathology
  • Brain / physiopathology
  • Brain Infarction / etiology
  • Brain Infarction / prevention & control
  • Brain Infarction / surgery
  • Cerebral Angiography
  • Craniotomy / methods
  • Craniotomy / standards
  • Humans
  • Intracranial Aneurysm / diagnostic imaging
  • Intracranial Aneurysm / pathology
  • Intracranial Aneurysm / surgery*
  • Magnetic Resonance Angiography
  • Medical Illustration
  • Neurosurgical Procedures / instrumentation*
  • Neurosurgical Procedures / methods*
  • Subarachnoid Hemorrhage / physiopathology
  • Subarachnoid Hemorrhage / prevention & control
  • Subarachnoid Hemorrhage / surgery
  • Surgical Instruments / standards