Ultrasonography And Fundus Fluorescein Angiography Examination Of Eyes In The Early Stages Of Gunshot Wounds To The Chest Of Pig

BackgroundGunshot wound in the chest is a serious trauma.It always injures ribs,the intercostal artery and leads to hemopneumothorax,respiratory failure,circulatory failure,so the survival rate was very low.Chest gunshot wounds accounted for about 12%among all the injuries.The incidence rate of gunshot wounds in the chest peacetime is between 3.1%and 11.8%,averaging 7.9%.However,in some countries which are lack of strict gun control regulations,the incidence of gunshot wounds in the chest are as high as 23%.Significantly increasing power of modern weapons available,injured more complex and higher mortality rates,the data,battlefield,chest gunshot wounds mortality rates are as high as 60.1%,the highest mortality heart gunshot wounds before those patients are sent to the hospital.Early causes of death for more heart,vascular injury and hemorrhagic shock,respiratory failure, after the rescue recovery procedure,many patients often died of acute respiratory distress syndrome.Because the early mortality rate is very high and doctors are also busy in CPR,it is difficult to observe changes in organs other than the chest,but with the level of rescue, survival time is extended,and the further study of the remote effects.There was also concerned that the changes in the organs in the chest gunshot wounds.ObjectiveGunshot wound to the chest animal model of production,using ultrasonic inspection and fundus fluorescein angiography gunshot wound in the chest early ocular tissue, vascular changes,analysis of hemodynamic parameters,and biopsy,were analyzed to understand gunshot wound in the chest after the eye structure,retinal perfusion and function. Materials and Methods1.Experimented animals:10 miniature pigs(5 of male and 5of female),weight 15.0～17.8kg,2.Anaesthesia:15mg/kg of ketamine anesthesia,intramuscular injection of atropine 0.02mg/kg neck until after the animals quiet fixed,establishing ear vein access,and 3g/L sodium pentobarbital anesthesia.3.Injuries caused by weapons are available:77-type pistol,7.62mm diameter,the initial velocity of 320m/s,firing-range 1m.Outdoor ranges injuries.Fixed,5 right chest before intercostal space to avoid slightly slanted toward the heart and great vessels(with the vertical lines into a 20-30 degree angle) to the road shooting Drive production model chest injuries.4.Investigation(1) Injury immediately after wound measured exits area of conventional wound debridement,bandaged.Observed by microscope.(2) Ultrasound equipment:ALOKA-5500 type color Doppler ultrasonic diagnostic apparatus.Eyes of animals were observed and checked before shot and after shooting (1/2h,6h,12h,24h).The measurement of central retinal artery systolic velocity(PSV). end-diastolic velocity(EDV),resistive index(RI) are also observed.(3) Fluorescence fundus imaging apparatus:(Japan Canon CF-60UD fundus cameras)conventional film photos,black and white photo,and fundus photographs taken fluorescence,calculated ear-retinal circulation time(E-RCT),retinal circulation time(RCT) and retinal completely developed time.5.The specimens were taken and executed immediately after death and animal anatomy,remove tissues for light microscopic examination.6.Statistics:SPSS statistical software for data analysis.Results1.Eye appearance:20 appearance eyes were observed no abnormal injury before shot, after injury,seven pig survived(14 eyes),among which 6 corneals are opacified.4 mild vitreous opacity and the others did not unusual.2.Two-dimensional ultrasound:The shapes of the eyes after injury are normal,and levels clearly.A little strong echo were finding in 4 eyes.Only two of which can be seen posterior vitreous detachment,one only partially associated with retinal detachment,no abnormal echo signal.3.Color Doppler flow imaging of central retinal artery before and after the injury: Within 24 hours after injury,central retinal artery PSV,EDV cut,RI increased,more wounded has changed significantly(P＜0.05);24 hours after injury,central retinal artery PSV animal survival.EDV slow recovery,RI has been gradually declining.4.Fundus photography:No bleeding,leakage were observed before and after wound.5.Fundus fluorescein angiography:ear-retinal circulation time(E-RCY) 7.0±0.6 seconds before injuries,1 hour 9.6±1.0 seconds after injury,which extend 1-4 seconds, there is significant difference between pre-injury and post-injury(P＜0.05);Before the injuries,retinal circulation tirne(RCT) 2.3±0.5 seconds,one hour after 2.6±0.5 seconds, which extended 0-1 seconds,no significant change in pre-injury is found(P＞0.05).Retinal completely developed time 12.6±0.8 seconds before injuries,1 hour 25.6±2.4 seconds after injury,which extend 9-16 seconds,there is significant difference between pre-injury and post-injury(P＜0.01)6.Pathology(1) Eye:iris,ciliary body,choroidal vessels dilated,blood cells deposit,the retinal nerve fiber layer edema,sensory nerve layer to layer between some limitations exudate exudative retinal detachment.(2) Lung:congestive,bleeding,and alveolar wall telangiectasia,bleeding,edema alveolar epithelial cells,fracture spacing,Focal acute puhnonary interstitial inflammatory cells example,a great deal of blood cells within the alveolar some partial lung bullae formation.(3) Heart:cardiomyocytes focal degeneration,telangiectasia,congestive,interstitial edema,swelling fiber,occasionally broken,Endocardial varying degrees bleeding.(4) Brain:brain cells swelling,perivascular space expanded focal neurons showed degenerative changes,focal hemorrhage.(5) Vascular:swelling of the aortic arch,vascular endothelial cells,some were not falling like a row of smooth muscle cells,osteoporosis,and the superior vena cava stretch endometrial pulmonary disorder.(6) Liver:lobular expansion bleeding of vein,subcapsular hemorrhage,bleeding within the liver,liver cells minor swelling.(7) Spleen:telangiectasia bleeding.Renal interstitial bleeding,renal tubular epithelial cells swollen balloon cavity smaller.Conclusions1.Remote gunshot wounds of chest leading to the organ injury does exist.2.High-frequency two-dimensional ultrasound and color Doppler flow imaging technique gunshot wound to the chest early eye changes to provide an accurate reference based on raising the level of clinical treatment.3.Funds fluorescein angiography gunshot wound in the chest,eye cycle has obviously slowed down,resulting in ischemia,hypoxia,lastly leaing to impaired visual function.