Study On The Relationship Between The Inflammation Of Deep Vein Thrombosis And The Perivascular Perfusion Of Contrast-enhanced Ultrasound In Rabbits

Objective: To establish a rabbit model of acute deep vein thrombosis(DVT),measure the levels of inflammatory factors in the peripheral serum and the tissues around the thrombus,study the correlation between the quantitative parameters of Contrast-enhanced ultrasound(CEUS)and the level of inflammatory factors.According to this correlation,we can quickly and accurately diagnose thrombosis,evaluate the inflammatory response of thrombus,and help the clinical early diagnosis of acute DVT and timely formulate the treatment plan.Methods: 64 New Zealand white rabbits,8 rabbits in the sham operation group(S group)and56 rabbits in the DVT model group.According to the time points of sampling: 2h,6h,12 h,24h,72 h,7d,2w,the thrombus model group was randomly divided into 7 subgroups(8 in each group).Acute DVT model was established by stenosis method,and thrombus length was measured by ultrasound.Enzyme linked immunosorbent assay(ELISA)was used to measure the concentrations of IL-6 and TNF-α in peripheral serum and perivascular tissues of all experimental rabbits.QLAB software was used to analyze the time to peak(TTP)and peak intensity(PI)of contrast media in perivascular tissue.Finally,analyzing the correlation between CEUS quantitative parameters and inflammatory factor concentration.Results:1.Animal survival and modeling: 61 rabbits out of 64 rabbits survived,with a survival rate of about 95%.There were 56 rabbits in the model group,and 53 rabbits were successfully moulded,with a success rate of about 95%.2.The maximum thrombus length measured by ultrasound: the thrombus length was the shortest in 2h group,the longest in 7d group(all P<0.05),and the thrombus length was slightly shortened from 7 days to 2 weeks.3.The concentrations of IL-6 and TNF-α in serum and perivascular tissues:The concentration of IL-6 and TNF-α in serum: The concentrations of IL-6 and TNF-α in12 h group were the highest,the concentrations of TNF-α in 6h group and 24 h group were higher than those in other groups(all P < 0.05).There was no difference in the concentrations of IL-6 and TNF-α in other groups(all P>0.05);The concentration of IL-6 and TNF-α in perivascular tissue: The concentrations of IL-6 and TNF-α in 2h group were the highest,the concentrations of IL-6 and TNF-α in S group were the lowest(all P<0.05).There was no difference in the concentrations of IL-6 and TNF-αin other groups(all P>0.05).4.Analysis of CEUS quantitative parameters in perivascular tissue:TTP comparison of each group: The TTP in S group was the largest,and that in 2h group was the smallest(all P<0.05).From 2 hours to 2 weeks,TTP increased gradually;PI comparison of each group: The PI in S group was the lowest,and that in 2h group was the highest(all P<0.05).From 2 hours to 2 weeks,PI decreased gradually.5.Correlation between CEUS quantitative parameters and inflammatory factor concentration in perivascular tissue:TTP was negatively correlated with the concentrations of IL-6 and TNF-α in serum and perivascular tissues,PI was positively correlated with the concentrations of IL-6 and TNF-α in serum and perivascular tissues(all P<0.05).Conclusion : Stenosis method which is used to make animal model of DVT has the advantages of high efficiency and high success rate,which can be used in DVT research for different experimental purposes.Two dimensional ultrasound is the first choice in the diagnosis of acute DVT,thrombus length and echo intensity can help to judge DVT stage.IL-6 and TNF-α are highly expressed in the early stage of acute DVT,which can promote thrombosis,and the level of inflammatory factors in local tissues is more timely and accurate to evaluate the degree of inflammatory response of thrombus.CEUS can be directly used to evaluate the local inflammatory response of DVT,which plays an important role in the early diagnosis and clinical treatment of DVT,so as to reduce the occurrence of serious complications.