[Blood-brain barrier opening microcirculation in human brain tumor].

The changes of the human tumor microcirculation after blood-brain barrier (BBB) opening was studied. BBB opening was performed by retrograde injection of hyperosmotic solution, such as mannitol or glycerol, from superficial temporal artery in the operation procedure. Serial fluorescein micro angiography of human tumor surface was taken by motor-driven camera equipped to surgical microscope. Two glioblastomas, two astrocytomas and one metastatic tumor were studied. In glioblastoma multiforme, after BBB opening, fluorescein sodium perfusion was increased with the enlargement of the venules and extravasation of fluorescein sodium was also observed from venules by the late venous phase of fluorescein microangiography. In low grade astrocytoma, after BBB opening, fluorescein sodium perfusion was relatively decreased in the vasculature which diameter was from 5 micron to 10 micron and no extravasation of fluorescein sodium was observed from the venules. In metastatic brain tumor, extravasation of fluorescein sodium was observed, ever before BBB opening, especially from arterial capillary or venous capillary. After BBB opening, extravasation of fluorescein sodium from those capillaries was increased and the tumor staining of fluorescein sodium was observed after BBB opening. But in low grade astrocytoma, BBB disruption was not observed. The effect of BBB disruption was more marked in malignant tumor, but little effect was observed in low grade astrocytoma and normal brain tissue. The degree of BBB disruption is depend on the volume and speed of hyperosmotic solution. Using our methods of volume and speed, we could observed the different BBB disruption according to the malignancy of the tumor. The difference of BBB reaction to hyperosmotic solution between low grade astrocytoma and malignant tumors is their stability of the BBB.(ABSTRACT TRUNCATED AT 250 WORDS)