What is effective in malignant middle cerebral artery infarction: Reperfusion, craniectomy, or both? An experimental study in rats

Background and Purpose-We sought to evaluate the effects of reperfusion and craniectomy treatment at different time points after middle cerebral artery (MCA) occlusion on infarct volume and neurological outcome in MCA infarction in rats. Methods-We used an endovascular technique to obtain MCA occlusion in 182 rats. Thirteen groups with 14 animals each were investigated: control group 1 with no treatment; groups 2 to 7 with only reperfusion or craniectomy at 1, 4, or 12 hours, respectively; and groups 8 to 13 with reperfusion at 1 or 4 hours combined with craniectomy at 1, 4, or 12 hours, respectively. We used infarct volume and neurological performance as study end points in all animals at day 7. Results-Neurological score and infarct volume in animals undergoing early reperfusion at 1 hour were significantly smaller (1.8/79+/-59 mm(3)) than those in control animals (3.8/225+/-26 mm(3)) (P<0.01). Reperfusion at 4 hours (2.8/182+/- 62 mm(3)) and 12 hours (3.7/231+/-69 mm(3)) did not result in significant improvement. Animals undergoing craniectomy at 1, 4, and 12 hours demonstrated significantly better outcome and significantly reduced infarct volume (1.6/96+/-30 mm(3), 1.9/109+/-39 mm(3), and 2.6/150+/-34 mm(3), respectively) (P<0.05). Compared with 1 treatment at a time, combined reperfusion and craniectomy did not result in a significant additional benefit. Conclusions-Early reperfusion and craniectomy at 1 hour are both effective in large MCA infarction. While reperfusion later than 1 hour was not beneficial, late craniectomy at 4 and 12 hours still resulted in significant improvement of neurological score and reduction of infarction size. Combined treatment at different time points yields no significant additional benefit compared with 1 treatment at a time.