Related Experiment Video
Updated: May 26, 2026

Protocol for Isolating the Mouse Circle of Willis
Published on: October 22, 2016
Cerebral arteriovenous malformations associated with flow-related and circle of Willis aneurysms
Xianli Lv1, Zhongxue Wu, Youxiang Li
1Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
Background:
To evaluate the characteristics of brain arteriovenous malformations (AVMs) with coexisting flow-related and Willis circle aneurysms.
Methods:
The 302 consecutive retrospectively reviewed patients from the Beijing Tiantan Hospital were analyzed in this study. The presence of cerebral aneurysms was confirmed by pretreatment selective and superselective angiography. Univariate and multivariate analyses were performed for patient age, sex, history of rupture, associated aneurysms, AVM size, and deep and superficial venous drainage.
Results:
Of the 302 patients, 41 (13.6%) had AVMs associated with intranidal aneurysms, and 33 (10.9%) had AVMs associated with extranidal aneurysms. Of the 33 patients, 24 (72.7%) had a flow-related and 9 (27.3%) had a Willis circle aneurysm. Flow-related and Willis circle aneurysms correlated positively with intracranial hemorrhage (P = 0.003), patient age (P = 0.003), and infratentorial AVMs (P = 0.040) in multiple univariate analysis.
Conclusions:
Flow-related and Willis circle aneurysms coexisting with cerebral AVMs frequently are associated with initial hemorrhage presentation, patient age, and infratentorial AVM location.
Related Concept Videos
The Arch of Aorta
Encircling the heart, the coronary arteries form a ring-like structure before...
Arteries of the Head and Neck
The internal carotid arteries supply blood to the anterior portion of the cerebrum. They enter the...
Cerebral Edema ll: Pathophysiology
Anastomoses
Anastomoses can be formed at arterial, venous, and lymphatic vessels.
Arterial Anastomosis: These occur between arteries. They are most common in...
Hemorrhagic Stroke l: Introduction
Cerebral Edema l: Introduction

