Experimental investigation of the “no-reflow” phenomenon

Abstract

The state of the vascular network of the brain was studied in 29 dogs by perfusion with ink after complete temporary arrest of the blood flow (ABF) for 5–20 min by mechanical asphyxia or fibrillation of the heart. In both groups extensive areas unfilled with ink were obtained for 7–8 min after ABF (the primary no-reflow phenomenon). The primary no-reflow phenomenon disappeared completely or became negligible after ABF for 10 min, and it reappeared in another form after ABF for 12–20 min (secondary no-reflow phenomenon). The no-reflow phenomenon was independent of the method of ABF and, consequently, of the presence or absence of hypercapnia and hypoxemia preceding the ABF, and it was determined only by the duration of the latter. The primary no-reflow phenomenon cannot be explained either by closure of the vessels by swollen processes of astrocytes or by thrombosis of the vessels.