Histomorphometrical study of the elastic fiber system in the anterior cerebral artery of man.

The aim of the present study was to quantify the distribution of the elastic fiber system within the wall of the anterior cerebral artery. The study is based on the works of Glynn (1940) and Stehbens (1989) concerning the incidence and origin of brain aneurysms and recent studies of the elastic fibers. The anterior cerebral artery was divided into three segments, S1, S2 and S3: S1 corresponds to the origin of the anterior cerebral artery, S2 is located at the junction of the anterior cerebral artery with the anterior communicating artery, and S3 at the junction of the rostrum and genu of the corpus callosum,which were submitted to routine histological procedures. A histomorphometrical study was undertaken using an estimation of the linear density (Ld) of the components of the fibrous elastic system which evaluates their full length in each segment. Data were analyzed using first order linear regression methods. The results show a decreasing quantity of elastic fibers in the three segments (S1>S2>S3). Study of the elastic fiber system may originate new concepts regarding the genesis of cerebral artery aneurysm.