| Part IThe Establishment of a Model for Dogs’ Pancreatic InjuryObjectiveA model for dogs’ pancreatic injury was established by injuring dogs’ pancreasdifferently with the ultrasound-mediated puncture in vitro, and then the modeling success rateand the dogs’ pancreatic injury were observed by operation and ultrasonic respectively, so asto lay a foundation for the subsequent experiment.Methods80local crossbreed dogs in Jinan were divided into four groups, and each groupconsisted of20dogs. After grouping, group I was punctured in vitro with theultrasound-mediation, the puncturing depth was less than1/2thickness of the pancreas, andeach dog was promptly punctured for3~5times; group II was punctured in vitro with theultrasound-mediation, the puncturing depth was1/2thickness of the pancreas, and each dogwas promptly punctured for3~5times; group III was punctured in vitro with theultrasound-mediation, the puncturing depth was greater than1/2thickness of the pancreas butshould be less than the entire thickness, and each dog was promptly punctured for3~5times;Group IV was punctured in vitro with the ultrasound-mediation, and the puncturing depth wasgreater than the entire thickness of the pancreas. After the puncture was completed, the resultsof the pancreas injuries were ultrasonically observed; the accuracy of the puncture modelingwas observed by operation. After all the above steps were finished, an experimental dog ineach group was put to death for obtaining the pathological mechanism, and then the case’sresult of the pancreas in the injured area was observed.ResultsThe number of the successfully modeled cases was17,16,19, and19respectively inGroup I, Group II, Group III, and Group IV. To the successfully modeled cases, the diagnosticrate of the conventional ultrasound was35.29%in Group I (i.e. injuries I-II in AAST Standard for the Grading of Pancreatic Trauma),56.25%in Group II (injury III in AASTStandard for the Grading of Pancreatic Trauma), and63.15%in Group III (injury Ⅳ in AASTStandard for the Grading of Pancreatic Trauma), and100%in Group IV (injure V in AASTStandard for the Grading of Pancreatic Trauma). From the case studies, the injured pancreaswas visible; the acinus structure in the pancreatic injured area was dissolved and destructed;the essential inflammatory cell infiltration was significant.ConclusionIn part I, the experimental modeling method featured easy-to-use, good controllability,and excellent correlation with the actual clinical conditions. Therefore, it is applicable to therelated researches of pancreas injury. Part IIExperimental Research on Contrast-enhanced Ultrasound in theEvaluation of Dogs’ Pancreas InjuryObjectiveIn part II, pancreatic injury was observed with contrast-enhanced ultrasound and alsograded using AAST Standard for the Grading of Pancreatic Trauma, so as to provide adiagnosis and treatment basis for the clinical practice.MethodsAfter the successful modeling in part I, each group was regularly examined withultrasound, and also the examination images were recorded. Subsequently, the ultrasonicimaging mode was launched by intravenously injecting ultrasound contrast agent forimplementing contrast-enhanced ultrasound examination. The diagnostic rate of ultrasonicimaging in AAST Standard for the Grading of Pancreatic Trauma was observed for eachgroup, and also the pancreatic injury images as well as the characteristics obtained fromcontrast-enhanced ultrasound were recorded. Finally, the diagnostics rates of the conventionalultrasound and the contrast-enhanced ultrasound to different grades of pancreatic injury werecompared.ResultsThe pancreatic injury model of the dogs in Group I was corresponding to the model ofinjury I-II in AAST Standard for the Grading of Pancreatic Trauma, and the diagnostic rate ofultrasonic imaging was52.94%; the contrast-enhanced ultrasound images showed the injuredareas were located in the superficial part of pancreas and enhanced unevenly, and lookedirregular in forms, fuzzy in boundaries, and unclearly divided with the surrounding pancreatictissues. The pancreatic injury model of the dogs in Group II was corresponding to the modelof injury III in AAST Standard, and the diagnostic rate of ultrasonic imaging was75%; thecontrast-enhanced ultrasound images showed the injured areas were enhanced lowly, thethickness was up to1/2thickness of the pancreas, and the boundary with the surroundingpancreatic tissues was clear, but an obvious echo fracture zone was not detected in the areas.Thepancreatic injury model of the dogs in Group III was corresponding to the model ofinjury IV in AAST Standard, and the diagnostic rate of ultrasonic imaging was78.94%; thecontrast-enhanced ultrasound images showed the injured areas were enhanced lowly, but thescope did not exceed the entire pancreas, the boundary of the lowly-enhanced areas was clear, and the boundary of the lightly-injured areas was enhanced lowly. The pancreatic injurymodel of the dogs in Group IV was corresponding to the model of injury V in AAST Standard,and the diagnostic rate of ultrasonic imaging was100%; the contrast-enhanced ultrasoundimages showed the injured areas was lowly enhanced or non-enhanced, and spreadthroughout the entire pancreas, but also their boundary was fuzzy. Thus, the pancreatic injurydisplay rate (78.87%VS64.79%) was improved by the contrast-enhanced ultrasoundcompared with the conventional ultrasound.ConclusionCompared with the conventional ultrasound, the contrast-enhanced ultrasound couldimprove the display rate, and also was more sensitive to pancreatic injuries I, II, III,&IVaccording to AAST grading of pancreatic trauma. Thus, it is of more distinctive significanceto clinical reference. Part IIIExperiment on Exploring the Relationship between the Degree ofDog’s Pancreatic Injury and the Degree of Dog’s Pancreatic DuctInjury in Contrast-enhanced UltrasoundObjectiveIn part III, the relationship between the degree of pancreatic duct injury and thecontrast-enhanced ultrasound image of pancreatic injury was explored by combining relevantbiochemical test with contrast-enhanced ultrasound examination, so as to provide empiricalguidance for some specific situations.MethodsGroups I, II,&III’s cases diagnosed in part II to be positive in contrast-enhancedultrasound were laparotomized and then placed in the pancreatic injury position’s drainagetube for closing the abdominal cavity. The amylase concentration in the drainage liquid after4days was recorded. According to the pancreatic fistular diagnosis standard specified in ISGPF,the degrees of the pancreas and pancreatic duct injuries represented by the drainage liquidconcentration of each group were analyzed.ResultsBiochemical results showed4cases suffered pancreatic duct injury and1case sufferedpancreatic fistular among Group I’s cases with a positive angiography result; Group II’s allpositive cases suffered pancreatic duct injuries, and9cases suffered pancreatic fistular; GroupII’s all positive cases suffered pancreatic duct injuries, and15cases suffered pancreaticfistular. In contrast-enhanced ultrasound, the pancreatic duct injury rate of the casesdiagnosed with injuries I-II according to AAST Standard was low, while all the casesdiagnosed with injuries Ⅲ-Ⅳ according to AAST Standard suffered pancreatic duct injury,and the incidence of pancreatic fistular was high.ConclusionFrom the test in part III, it was known that pancreatic duct was injured differently andalso the pancreatic fistular rate was very high (more significant in injury Ⅳ) among the casesdiagnosed with injuries Ⅲ-Ⅳ according to AAST Standard for the Grading of PancreaticTrauma in contrast-enhanced ultrasound, while only a few cases diagnosed with injuries I-IIsuffered pancreatic duct injury, and the pancreatic fistular rate was very low. |
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