Establishment of cerebral vasospasm model after subarachnoid hemorrhage in pigs

Objectives To establish a pig subarachnoid hemorrhage (SAH) model and observe the changes of cerebral blood perfusion. Methods The pigs were randomly divided into SAH group (n = 5) and sham-operated group (n = 4). SAH model were established via the injection of autologous arterial blood into the suprasellar cistern, while the sham-operated group was injected with normal saline instead. SPECT-CT infusion scans were applied after 4 days, then parameters corticocerebellar ratio (CCR) and relative dispersion (RD) were utilized for quantitation of cerebral hemisphere blood flow and flow dispersion. HE staining was applied to observe the neuronal histological changes of the hippocampus at 7 d. Results CT imaging showed blood accumulated successfully in the suprasellar cistern in SAH group. The left and right hemisphere CCR (1.768 ± 0.298 and 1.382 ± 0.192) in SAH group were significantly decreased compared with the corresponding side of sham- operated group (2.131 ± 0.246 and 1.988 ± 0.346) (P 0.05). There was significant difference of CCR between the two sides in the SAH group (P 0.05). RD in right side of SAH group (0.417 ± 0.015) increased compared the ipsilateral sham-operated group (0.389 ± 0.015) (P 0.05), however, no significant differences were showed in the left side between SAH group (0.406 ± 0.023) and sham-operated group (0.378 ± 0.030) (P 0.05). No difference of RD appeared between the two sides in the SAH group (P 0.05). HE staining showed that the morphology of hippocampus neurons were abnormal in SAH group. Conclusion The pig SAH model has a characteristics of abnormal blood flow perfusion which is consistent with the features of vasospasm induced SAH, thus being an ideal large animal model for research of related diseases.