This Article Full Text Full Text (PDF) All Versions of this Article: 35/5/1153    most recent 01.STR.0000124926.76836.dfv1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Canham, P. B. Articles by Finlay, H. M. Search for Related Content PubMed PubMed Citation Articles by Canham, P. B. Articles by Finlay, H. M. Related Collections Cerebrovascular disease/stroke Other Vascular biology Brain Circulation and Metabolism Cerebral Aneurysm, AVM, & Subarachnoid hemorrhage

(Stroke. 2004;35:1153.)
© 2004 American Heart Association, Inc.

Original Contributions

Morphometry of Medial Gaps of Human Brain Artery Branches

From Department of Medical Biophysics (P.B.C., H.M.F.), University of Western Ontario, London, Ontario.

Correspondence to Dr Peter B. Canham, Department of Medical Biophysics, Faculty of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada, N6A 5C1. E-mail pcanham{at}uwo.ca

Background and Purpose— The bifurcation regions of the major human cerebral arteries are vulnerable to the formation of saccular aneurysms. A consistent feature of these bifurcations is a discontinuity of the tunica media at the apex of the flow divider. The objective was to measure the 3-dimensional geometry of these medial gaps or "medial defects."

Methods— Nineteen bifurcations and 2 junctions of human cerebral arteries branches (from 4 male and 2 female subjects) were formalin-fixed at physiological pressure and processed for longitudinal serial sectioning. The apex and adjacent regions were examined and measurements were made from high-magnification photomicrographs, or projection microscope images, of the gap dimensions at multiple levels through the bifurcation.

Results— Plots were made of the width of the media as a function of distance from the apex. The media at each edge of the medial gap widened over a short distance, reaching the full width of the media of the contiguous daughter vessel. Medial gap dimensions were compared with the planar angle of the bifurcation, and a strong negative correlation was found, ie, the acute angled branches have the more prominent medial gaps.

Conclusions— A discontinuity of the media at the apex was seen in all the bifurcations examined and was also found in the junction regions of brain arteries. We determined that the gap width is continuous with well-defined dimensions throughout its length and average length-to-width ratio of 6.9. The gaps were generally centered on the prominence of the apical ridge.

Key Words: cerebral aneurysm • connective tissue disorders • cerebral arteries • histomorphometry