[Effects of injecting heparin into the center of hematoma on peri-hematoma edema and hematoma volume in pigs with intracerebral hemorrhage].

OBJECTIVE: To investigate the safety and effect of injecting heparin into hematoma on peri-hematoma edema and hematoma volume in pigs with intracerebral hemorrhage (ICH). METHODS: Thirteen sucking pigs were divided randomly into two groups: hemorrhage group, in which 2.5 ml arterial blood was injected into the right frontal lobe and heparin group, in which 0.2 ml of heparin was injected into the hematoma produced by the injection of 2.3 ml of blood into the similar site. The hematoma volume and peri-hematoma edema were determined by the sequences of T2* weighted image (T2*WI), fluid-attenuated inversion- recovery (FLAIR) image and diffusion weighted image (DWI) by 1.5 T magnetic resonance image (MRI) from 30-60 minutes afterwards to 24 hours. The peri-hematoma apparent diffusion coefficient (ADC) was compared with that of contralateral hemisphere, and the corresponding histologic changes were studied. RESULTS: The average volume, shown by T2*WI at 24 hours, was significantly larger than that at 30-60 minutes after hematoma formation in hemorrhagic group [(5.29+/-0.98) cm3 vs. (3.09+/-0.38) cm3, P<0.01]. But there was no significant change in hematoma volume in hemorrhagic group from 30-60 minutes on to 24 hours [(2.21+/-0.28) cm3 vs. (2.33+/-0.30) cm3, P>0.05]. Both increased and decreased ADC were found around the hematoma in some animals of the heparin group compared with that of the contralateral hemisphere. On the other hand, in hemorrhagic group, only increased ADC could be found around the lesion, and there was no decreased ADC. CONCLUSION: Injection of heparin into an intracerebral hematoma leads to enlargement of the hematoma and more marked peri-lesion edema. On ADC maps, enlargement of hematoma is attributed to the edema around the lesion leading to injury to the brain tissue.