Treatment-induced neoangiogenesis in cerebral arteriovenous malformations

We investigated the angiogenetic and proliferative activity of the endothel ium of 30 consecutive surgical cases of AVM treated at our institution by i mmunohistochemical detection of the PCNA, MIB-1, Flk-1 and VEGF antibodies. Endothelial positive immunostaining was observed in 87% of the cases for P CNA, in 20% for MIB-1, and in 80% for Flk-1. Of 22 individuals treated with incomplete embolization prior to surgery, 17 showed an expression of VEGF (77%), but only two of the eight patients (25%) who were treated without pr ior embolization exhibited such an immunoreaction (P = 0.0086). The prolife ration and growth of cerebral AVMs is documented by endothelial expression of PCNA and MIB-1. The statistically significantly higher expression of VEG F in partially obliterated (embolized) AVMs is most likely caused by transi ent regional hypoxia within the AVM nidus that mediates neoangiogensis. It points out the clinical relevance of a complete occlusion in order to avoid neovascularization associated with subsequent morbidity and mortality. (C) 2001 Elsevier Science B.V. All rights reserved.