Comparison of different intravascular thread occlusion models for experimental stroke in rats

For the induction of ischemic strokes of varying sizes in rats, different types of threads were used to occlude the middle cerebral artery (MCA) in combination with or without the posterior communicating artery (PCOM) and the common carotid artery (CCA). During vessel occlusion brain tissue partial oxygen pressure (ptiO2) and regional cerebral blood flow (rCBF) were monitored using a combined ptiO2/laser Doppler flow probe. Following neurological assessment animals were sacrificed at 3, 8 and 24 h and the necrotic volume was measured on serial coronary slices. In another experimental group, rCBF was measured 1h post-insult with the iodo[14C]antipyrine method. Animals with selective MCA occlusion showed less reduction of ptiO2 and rCBF and smaller infarcts when compared with animals with combined occlusion of the MCA, CCA and PCOM. Both groups, selective MCA occlusion and combined occlusion of the MCA, CCA and PCOM, demonstrated a high reproducibility and low variability of stroke size. Relative growth of stroke size within 24 h was higher in animals with selective MCA occlusion. Therefore, the selective MCAO model may be advantageous for studies of neuroprotective strategies.