Neuroprotective effects of hemicraniectomy in malignant middle cerebral artery infarctions: experimental study.

Abstract

Despite optimal medical therapy the mortality rate approaches 50% in MCA infarctions. Although recent studies have been showed life-saving effect of hemicraniectomy; there are a few data available in regard to neuroprotection effect of decompressive craniectomy (DC). We induced a malignant cerebral ischemia model by intraluminal permanent middle cerebral artery occlusion (MCAo) in male rats for defining the neuroprotective effects of early DC on brain-blood barrier (BBB) molecular changes, infarct size and cerebral edema. A total of 48 male Spraque-Dawley rats were allocated to 4 groups; sham (N.=9), control (N.=9), experiment 1 (N.=15), experiment 2 (N.=15). DC was performed by creating a bone flap, after MCAo at 4 and 24 hours. After 28 hours of survival, all animals were sacrificed. Infarction volumes were calculated from TTC (2,3,5-triphenyl-2H-tetrazolium chloride)-stained brain sections. In all groups, cerebral edema was quantified as a change in the percentage of brain water content. Western Blot was used to analyze the expression of tight junction protein claudin-5 and occludin. Brain water content was calculated 75.18±0.75% in the early DC group and 77.76±0.71% in the late DC group. No significant difference was found between experiment groups (P=0.178). In the early DC group; occludin and claudin-5 were significantly expressed at higher levels compared to late DC group (occluding, P=0.013; claudin-5, P=0.034). At early DC group (73.38±23.11 mm3) the final infarct volumes were significantly smaller than in the late DC group (377.18±39.23 mm3) (P=0.013). The study results supported the neuroprotective effects of early DC in malignant MCA infarcts.