Establishment Of A New Model Of The Explosion Injury To The Dog Brain And The Diagnostic Value Of Sequential CT Scanning After The Explosion Injury To Brain

Backgrouds: With the development of the science and technology and the use of all kinds of new type weapons, the number of man suffered from explosion is over the man suffered from gunshot during modern war.Explosion is becoming the main type of wound(accounts for the 70%-90% of all wounds). Explosion injury is becoming the research emphasis of modern firearm injury. The main problem in the study of cerebral firearm injury is how to establish an animal model of which the traumatic condition not only corresponds with the reality of clinical craniocerebral trauma but also is observed continuely and can be treated in time.If the survival time of the model is too short, there is no way to study the pathophysiology and pathomorphology of it with more details. To choose the suitable model to do prospective study can futher help increase the clinical remedy level. Now there comes no ideal experimental animal model used for studying cerebral explosion injury in our world.The spherical explosive has stable dynamite dosage.Its explosion parameter is identified and the explosion detonation energy can be controlled. The spherical dynamite explodes with flexibilite primacord. The detonating point locates at the end of flexibilite primacord at the center of dynamite. The blast wave is spherical and the distribution of pressure field has isotropy. It imitates the blast wave produced by explosion. During detonating the powder burns thoroughly. It does not produce fragments and has no detonation remnants. The animal model established in this experiment can be corresponded with the mechanism of primary effect of the blast wave produced by the explosive weapons. The other interaction factors are shielded successfully and the wound agent is simple.The best advantage of thid model is that it can simulate different degree cerebral explosion injuries through adjusting the dynamite dosage of the spherical explosive(dynamite energy) and changing the distance between the animal and the vulnerating device(vulnerating energy). Zhang-ming et al established an animal model of maxillofacial explosive injury by the new spherical explosive and did some rudimental researching. It can be used in experimental study of craincerebral explosion wound.Objective: To establish an experimental model of the explosive injury to the dog brain which correspond with the mechanism of primary effect of the blast wave of explosive weapons. To explore the CT diagnostic value of the craniocerebral injury by the mechanism of primary effect of the blast wave of explosive weapons.Methods: A spherical explosive with explosive energy of 1gTNT was used to detonate at different distances to cause the explosion injury to the dog brain.The changes of physiological index before or after detonating and the surviving time after injury were recorded. The changes of the behavior of the wounded animals and characteristic of pathological changes of the brain were observed . The dog heads were coronalisly scanned at 0h ,12h, 24h after explosion.The CT characteristics were observed.Results: Respiratory arrest, hypotension, and decreased heart rate were observed after wounded. All animals survived more than 6 hours after the explosion injury. Subdural hematoma and sub-arachnoid hemorrhage was significant. Spherical explosive detonating at different distances, traumatic condition of the brain was different. Hematocele in frontal sinus, contusion and laceration of brain,subdural hemorrhage,epidural hematoma, intracranial hematoma, pneumocephalus and skull fracture were found by the immediate CT scan after wounded. The enlargement tendency of low density circumsciption of the contusion and laceration of brain were traced by the sequential CT scanning.Conclusions: The animal model established in this experiment can be corresponded with the mechanism of primary effect of the blast wave of explosive weapons. It is stable, reproductive, easy to handle, and can be used in experimental study of craincerebral explosion wound. The extensional traumatic condition of the explosion injury to brain can be determined by the first CT scanning. The development of the intracranial hematoma and contusion and laceration of brain may be traced by sequential CT scanning.