EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH-FACTOR IN PEDIATRIC AND ADULT CEREBRAL ARTERIOVENOUS-MALFORMATIONS - AN IMMUNOCYTOCHEMICAL STUDY

Children and adults may differ with respect to their cerebral vasculat ure in both normal and pathological stales. The authors have identifie d four pediatric patients in whom a cerebral arteriovenous malformatio n (AVM) recurred after surgery Cor removal of the AVM and in whom a no rmal postoperative angiogram had been obtained. This phenomenon has no t been observed in adults. Th propensity to regrow a cerebral AVM may reflect a less mature cerebral vasculature and a disregulated angiogen ic process. Recently, attention has focused on vascular endothelial gr owth factor (VEGF) as a possible general mediator of angiogenesis in d evelopment and neoplasia. A retrospective immunocytochemical analysis of VEGF expression in AVM tissue was conducted to test the hypothesis that VEGF expression may be found in association with the ri growth of AVMs. The results demonstrate a high degree of astrocytic VEGF expres sion in four (100%) of four specimens from tile initial operation in t he children with recurrent AVMs as compared to one (14%) of seven nonr ecurrent AVMs in the pediatric and two (25%) of eight adult specimens. All of tile specimens from the first operation of the recurrent group demonstrate a clear association of cellular immunoreactivity to the a bnormal brood vessels, a relationship that was not observed in the spe cimens from the nonrecurrent groups. These observations indicate that a humoral mechanism mediated by VEGF may play a role in AVM recurrence .