Experimental Study Of Regeneration After Closed Liver Trauma In Rabbits By Contrast-enhanced Ultrasonography

Objective:Observe image features after closed liver trauma in rabbits by ultrasonography and contrast-enhanced ultrasonography and blood clotting tests and liver function tests and routine blood tests and pathological changes,to explore the relation between the contrast-enhanced sonography imaging and pathological changes after the closed liver trauma and verify the feasibility and accuracy of contrast-enhanced sonography in the regeneration,and then more proof for evaluation could be provided.Methods:The first part research image features after closed liver trauma in rabbits in different period by ultrasonography and contrast-enhanced ultrasonography. New Zealand big white rabbit Supine fixed on the table were intraperitoneal injectioned ketamine 0.15 ml/㎏ , Experimental self-made BIM -Ⅳtype biological hit device impact experiments The rabbit liver area , Established the experimental model of closed liver trauma ,liver trauma were created in the livers of 21 rabbits, which were divided into three groups randomly. Animals underwent hepatic trauma after performing ultrasonography and contrast-enhanced ultrasonography instantly and at 3 days,1 week after closed liver trauma procedure respectively. Observe and record image features after closed liver trauma of hepatic parts,range,boundary,liver capsular rupture,active bleeding or not,intraperitoneal hemorrhage or not, The correlation between contrast-enhanced ultrasonography and pathologic findings was contrasted.The second part research the change of blood clotting and liver function tests and routine blood tests after closed liver trauma in rabbits in different period.In the frist place basis, ultrasound examination was performe before the injury,6h,12h,24h,48h,3d, detectioning the ALT,AST,PT,APTT,TT,Fib,WBC,RBC,PLT,research the change of blood clotting and liver function tests and routine blood tests after closed liver trauma.The third part researched the correlation between contrast-enhanced ultrasonography and pathologic findings was investigated and Immunohisto-chemistry was used to detect the expressions of VEGF,ki-67. In the frist place basis, Animals underwent hepatic trauma after performing ultrasonography and contrast-enhanced ultrasonography instantly and at 3 days,1 week after closed liver trauma procedure respectively. Use volume fraction of formaldehyde solution for 4% of fixed, Paraffin embedding, slice by 5um, dyeing by HE, light-microscopy its organization form_infected, Immunohisto-chemistry was used to detect the expressions of VEGF,ki-67.Results:24 New Zealand big white rabbit Successfully established the experimental model of closed liver trauma, The hepatic injuries were classified as AAST gradeⅡ.Conventional ultrasonic: Trauma instantly group liver trauma's ultrasonographic no changed, Heavier trauma area liver trauma echo slightly increased, Post-traumatic 3d group include subcapsular and essence of liver inside the hematoma was displayed for the strength of the intrahepatic irregular ranging from the echo,Some of which are isoechoic or approximate isoechoic,damaged area boundary not clear, was not easy to recognize,CDFI shows no obvious damage area of blood flow signals,Post-traumatic 7d group trauma area since the peripheral tissues in the arterial phase to internal began to increase,trauma centers still is no enhancement, portal phase is low enhanced.Pathology changed:trypan-blue and display that trauma with normal liver tissue focal dyeing different in trauma instantly group,trauma in cell focal degeneration and interstitial area visible congestion, bleeding,Post-traumatic 3d group intrahepatic vessels structure form did not see abnormalities liver sinus no congestion, expansion, liver cells did not see degeneration and necrosis,liver did not see edema and inflammatory cells infiltrating change focal liver cells in trauma coagulative necrosis,necrosis with normal liver tissue focal visible inflammatory cell border, with lymphocytes, mainly neutrophils.Post-traumatic 7d group expression for necrosis with normal liver tissue focal junction visible, there was a little small vessels into fiber cell hyperplasia, at the same time with little inflammatory cell.Immunohistochemical detection for VEGF express positive cells for cytoplasm or cell membrane uniform claybank dyeing.trauma instantly group did not see VEGF positive cells express.Post-traumatic 3d group expression for VEGF positive cells (+) and dyeing strength weak.Post-traumatic 7d group expression for VEGF positive cells (+ +), dyeing strength is strong.Liver function changed:Post-traumatic ALT, AST, leukocyte count, and increased levels of normal control group comparison, a statistically significant difference(P<0.05).ALT 6h beginning to rise after the injury, after 12h peak, slow drop, basic recovery after the injury to trauma 3d former level.AST in post-traumatic after 6h peaked, slow drop, from post-traumatic 3d basic recovery before the trauma levels.Blood-test changed:White blood count in post-traumatic 6h rise very obvious, 12h peak, after slow drop.Red blood cell count and platelet count have a statistically significant difference reduced (P < 0.05).Red blood cell count in post-traumatic 6h dropped significantly, 24h peaked, elevated 48h before,3d can reach trauma levels.Platelet count post-traumatic appear immediately reduce, post-traumatic 6h obviously reduced, to post-traumatic 3d reaches lowest.Coagulant function changed:APTT post-traumatic 6h-12h increased significantly after peak, fell rapidly,PT post-traumatic 6h lifts quickly, 12h-24h reaches the bottom dropped. TT post-traumatic 6h to reduce,24h in the rut.Conclusion:Contrast-enhanced ultrasonography imaging diagnosis liver closed damage obvious sensitivity than conventional higher and pathological findings were medium consistency.Along with the trauma of prolonged, contrast-enhanced ultrasonography in different periods images shown are their respective characteristics.Contrast-enhanced ultrasonography imaging can an accurate reflection of the pathological changes.Contrast-enhanced ultrasonography is closed liver post-traumatic evaluation methods reliably recovered and cound be used as liver tissue repair process after a trauma observation means of inspection.