[Histological changes in the superficial temporal artery and their significance for extracranial-intracranial bypass operations]

To obtain criteria for assessing the "suitability" of an extracranial artery to be used as a donor artery in extracranial-intracranial bypass operations we examined first of all the histological changes in 103 temporal arteries of patients on whom EC/IC bypass surgery had been performed. The intima, which consists of one to two cell layers in adolescents, thickens in the course of the following decades locally or concentrically, in some cases incorporating elastic elements during the process. No arteriosclerotic plaques were seen. The originally continuous, plicated lamina elastica interna shows increasing defects in continuity in the course of the aging process, as well as loosening up to the point of fragmentation, especially in the field of the intima padding. The tunica media which is at first 30-80 mu thick, continuous to thicken in the course of life; in 60-year old persons it attains a thickness of approximately 200 mu. The changes described here occur 1.) in men in a particularly characteristic age-dependent manner; 2.) not earlier than in healthy persons, as far as the patients studied by us seem to show; and 3.) do not show any dependence on the vascular process described in this article.