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Updated: Jun 24, 2026

Arterial Pouch Microsurgical Bifurcation Aneurysm Model in the Rabbit
Published on: May 14, 2020
[Basic research on Charôt-Bouchard microaneurysms: a pathological study on their etiology using surgical specimens]
1Chiba Institute of Science, Choshi 288-0025, Japan. nfukudome@cis.ac.jp
Abstract:
For the past 140 years, intracerebral hemorrhages (ICHs) and miliary aneurysms have been in widespread controversy focusing on autopsied brains. Between 2004 and 2005, the author performed pathological and three dimensional reconstructive studies in surgical specimens that neurosurgeons had confirmed as bleeding points during microsurgery to be the cause of an intracerebral hemorrhage. All of small arteries collected from 42 patients revealed acute arterial dissections at 126 points. And a not ruptured miliary aneurysm was found, of which wall consisted of collagen fibrils. The possibility of rupture in the future was deemed high, with the risk of an ICH. In addition, an acute arterial dissection with the circumference of whole the muscular layer was found and showed thickened collagen fibrils in the adventitia. This type of dissection was thought to have possibility of the cause of the miliary aneurysm.
Insights
Acute arterial dissections in small arteries are the cause of intracerebral hemorrhages (ICHs) and miliary aneurysms. These dissections, found in surgical specimens, reveal arterial wall abnormalities, highlighting future rupture risks.
Area of Science:
- Neuropathology
- Vascular Biology
- Microsurgery
Context:
- Intracerebral hemorrhages (ICHs) and miliary aneurysms have historically been studied using autopsied brains.
- Surgical specimens provide direct evidence of bleeding points during microsurgery.
Purpose:
- To investigate the pathological basis of intracerebral hemorrhages (ICHs) and miliary aneurysms using surgical specimens.
- To identify the precise cause of bleeding points confirmed during neurosurgery.
Summary:
- Pathological and 3D reconstructive studies were performed on surgical specimens from 42 patients.
- Acute arterial dissections were identified at 126 points in small arteries.
- A non-ruptured miliary aneurysm with a collagenous wall and an arterial dissection involving the entire muscular layer with thickened adventitial collagen fibrils were observed.
Impact:
- Findings suggest acute arterial dissection is the cause of ICHs and miliary aneurysms.
- Identifies specific arterial wall pathologies, including collagen abnormalities.
- Provides new insights into the pathogenesis of these cerebrovascular conditions, potentially improving risk assessment and future research directions.

