Effects of decompressive craniectomy, hypothermia and their combination in a permanent focal cerebral ischemia model

Hypothermia has a neuroprotective effect in cerebral ischemia and reduces brain edema, and decompressive craniectomy (DC) can prevent brain herniation caused by massive brain edema. Thus, combination of the two therapies may be more effective in large hemispheric infarctions, by exerting an additive effect. We investigated the effects of DC, hypothermia, and their combination in experimental cerebral ischemia. Seventy rats received focal cerebral ischemia for 72 hours and were allocated to one of four groups: untreated control (n=29), DC (n=21), hypothermia (n=10), and DC plus hypothermia (n=10). Hypothermia (34°C) and/or DC were performed 6 hours after ischemia. Mortality was 44.8% (control), 28.6% (DC), 10.0% (hypothermia), and 0% (DC plus hypothermia), respectively (p<0.05). Compared to control (260.2±100.8 mm 3 ), the size of the infarction was not reduced by DC (236.3±94.3 mm 3 ), p>0.1) but was by hypothermia (117.8±50.7 mm 3 ), p<0.01). Although hypothermia combined with DC reduced the size of the infarction significantly (99.6±71.2 mm 3 ), no additional effect was observed versus hypothermia alone.