Objective      To establish a model of traumatic intracerebral hemorrhage (tICH) in miniature pigs exposed to simulated high altitude.      Methods     Twenty-nine miniature pigs were randomly assigned to 4 groups

high altitude tICH group （n=11）

plain tICH group （n=11）

high altitude sham operation group （n=4）

plain sham operation group （n=3）. After healthy miniature pigs were raised in hypobaric chamber simulating 4 000 meter high altitude for 3 d

they were inflicted with a slow injection of 3 ml fresh autologous arterial blood into the right basal ganglia to mimic tICH. The minipigs who received same blood injection under normal plain condition served as control. CT scanning was carried out in 2 h before and immediately after tICH induction

then the cerebral samples were taken out in 168 h after tICH induction

and the hematoma volume was calculated by stereological method. Arterial blood gas were monitored in 2 h before and in 2

24

72 and 168 h after tICH induction. Animal behaviors were evaluated with Purdy neurological function assessment in 2 h before and in 24

72 and 168 h after tICH induction. Morphological changes of brain tissues were examined by HE and Nissl stainings.     Results      Hematoma in the basal ganglia was successfully induced

and the volume of hematoma was distinctly diminished in 168 h (P0.01). But there was no significant difference in the volume between high altitude tICH group and plain tICH group (P0.05). In 24

72 and 168 h after tICH induction

there were significant differences in blood gas analysis (P0.01) and total neurological scores  between high altitude tICH group and plain tICH group (P0.01). Injuries in neuron nuclei and Nissl bodies around the hematoma were more severe in high altitude tICH group than plain tICH group.     Conclusion      The model of tICH in miniature pigs exposed to simulated high altitude can produce stable hematoma volume and visible neurological deficits.