A LMCWanimal model in cat was reproduced according to Carey′s method. Twelve cats were divided into two groups with 6 in each. In one group low velocity missile craniocerebral wound (LMCW) was produced (C group), and in another dextran 40 was given after the injury(Dex40 group). Pial microcirculation was observed in vivo under transluminal microscope, and pial microvessel caliber was also measured. Microregional cerebral blood flow (CBF) was measured with laser doppler flowmetry. Blood samples were collected at 5 time points for surveying and calculating blood rheological parameters. Brain tissues and brain microvascular corrosion casts were obtained for light and electronic microscope observation. There was vasoconstriction of the pial arterioles and venules immediately after the injury,lasting for about 30min. In C group, they dilated 1h later, and returned to normal at 2h,again vasoconstriction appeared in the arterioles from 5h to 8h, while there was vasodilatation of the venules. All blood rheological parameters rose significantly, and did not recover to normal after 8 hours. Petechial hemmorhage, swelling and damage of the nerve cells were found in the parietal lobe contralateral to the trauma. Microthrombosis and occlusion were observed in some microvessels. When the injured mice were treated with dextran 40 micro regional CBF and blood rheological changes were improved. We conclude that Dextran 40 ameliorates the cerebral microcirculation disturbance through improving the blood rheological changes following low velocity missile craniocerebral wounds, and Dextran 40 may be useful in clinical practice.

Objective To study the method for early treatment and Ⅰ-stage repair of the acute facial and brain injuries and its significance. Methods A retrospective study was performed in 38 cases with acute cranial injury,who underwent early treatment and surgical repair of the cranial bone and/or dura defects with self-tissues,glue material and titanium net depending on individual conditions. Of all,33 cases (87%) received Ⅰ-stage repair. Antibiotic therapy was performed in all the cases after operation. Results All patients recovered with satisfactory regional appearance. No intracranial infection or rhinorrhea of cerebral spinal fluid occurred among them during the follow-up for from six months to 11 years. Conclusion For the acute facial and brain injuries,early treatment and Ⅰ-stage repair based on the injury site and injury severity can attain safe and effective results.