| Object: Through the establishment of animal models with venousthrombus, ultrasound was used to detect the early venous thrombus, and thepathological analysis was combined to make a preliminary assessment on thechanges of early vein thrombus in order to guide to grasp the adequate clinicaltreatment opportunity and reduce the complications.Materials and methods:1. Establishment of rabbit models with veinthrombus: One side of the rabbit’s jugular vein was ligatured and injected withthrombin to make thrombus.18rabbits were randomly divided into6groupsthat were1,3,5,7,14and21-days group respectively with each group of threerabbits.2. Ultrasound examinations: Preoperative and postoperative diametersof bilateral jugular vein, preoperative blood flows and postoperativethrombogenesis were tested, the images were saved and the data were recorded.At an interval of1,3,5,7,14and21days after thrombus modeling,observation was carried out, respectively.3. Pathological examinations:Ultrasound was used to examine each group according to the schedule timeperiod. After thrombogenesis, thrombus were taken out according to thecorresponding grouping time and made into pathological sections throughparaffin embedding, thus its pathological manifestations were observed underlight microscopy.Results:1. Thrombus models in all of the18rabbits’ jugular veins weresuccessfully established.2. Results of ultrasound examinations:(1)Measurement results of the diameters: Preoperative measurement results of thediameters had statistically significance with all the groups (P <0.05) except the 21-day group (P>0.05); When compared with the1-day group, the differencewith the other groups all had statistical significance (P <0.05) except the3-daygroup (P>0.05); When compared with the3-day group, the statisticallysignificant differences had been found in7,14and21-day groups (P <0.05)but not in the5-day group (P>0.05); When compared with the5-day group,the difference with that of the7,14and21-day groups all had statisticalsignificance (P <0.05); When compared with the7-day group, the differencewith the14-day group had no statistical significance (P>0.05) but there hadstatistical significance through the comparison with the21-day group (P <0.05);And the differences between the14-and21-day groups were not statisticallysignificant (P>0.05).(2) Echo intensities of venous thrombus in the1,3and5-day groups were not significantly different. Echoes in part of the cases wereslightly increased after7days and significantly increased after21days.3.Results of pathological examinations: The venous lumen was full filled withthrombus; For the first1~3days, no obvious adhesions between thrombus andtube wall were seen, after the5th day only small amount of adhesions appeared,and then the obvious adhesions appeared at the7th day, serious adhesionsoccurred at the14th day and further serious adhesion at the21th day;Organization phenomenon could be seen at the3th day and obviousorganization on the7th day; on the14th day granulation tissue had gone deepinto the inside of the thrombus, and on the21th day the thrombus had all beenreplaced by granulation tissue.Conclusion:1. The method establishing the vein thrombus models byligaturing rabbit jugular vein and injecting thrombin was convenient andreliable with stable thrombus.2. The diameter enlarged after1day venousthrombosis in rabbit jugular vein;1~21day venous diameter retraction changedperiodically rather than linearly, so the changes could be used to speculate theage of thrombus.3. On the21th day after venous thrombosis in rabbit jugular vein, the diameter was retracted closely to the original diameter, the thrombustended to be stable and the risk to fall off was lower.4. Rabbit jugular veinthrombus formation within3days after the valve did not see obvious damage,within three days if removing blood clots for thrombolysis is significant forprotecting valve, five days after the valve damage obviously, makes little senseto protect the valve to treatment. |
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