Experimental Study On Contrast-enhanced Ultrasound To Evaluate Testicular Microvascular Injury

ObjectiveThe CEUS and quantitative analysis technology are applied to assess testicularmicrovascular ischemia-reperfusion injury, to explore a noninvasive, feasibleapproach to evaluate the testicular microvascular injury.MethodsCreated phospholipid microbubbles (MB) and detect its acoustic characteristicsrelated.Healthy adult male white rabbits were randomly divided into control group(sham group/group S), microvascular ischemic injury group (group I, includinggroup I1, I2, I3), microvascular reperfusion group (group R, including group R1,R2,R3,R4）, Atotal of eight groups, each of6. Randomly selected one testis, with ultrasoundmonitoring, the spermatic cords2cm above the testicle were ligated until testicularblood flow completely disappeared, to establish testicular completely ischemia model.Among them, Group I1, I2, I3were ischemic2h,4h,6h to establish mild, moderateand severe testicular microvascular ischemic injury model, and then reperfusion2h;Group R1, R2, R3, R4were re-established1h,2h,4h,6h respectively after ischemiareperfusion4h, to establish varying degrees of testicular microvascular reperfusioninjury model. the S group was threaded but not ligated. Testes MB CEUS wereundertook preoperative and postoperative respectively. Ultrasound contrastangiographic parameters of each group were analyzed with quantitative analysistechniques, including PI、TP、Slope、MTT、DT/2and Area. Laboratory test the levelsof plasma, which were obtained by cardiac puncturevon guided by color Dopplerultrasound, Willebrand factor (vWF), nitric oxide (NO), endothelin-1(ET-1) afterCEUS. Get the ipsilateral testicular to stain H.E. and immunohistochemicalstaining(MMP-9) after the operation and observe the pathological changes of eachgroup. Statistical analysis was performed by SPSS13.0software. all data are expressed in x±s. two sets of data were compared by two independent samples T test.Differences in test level is set to P <0.05(bilateral).ResultsLipid microbubbles is milky white turbid liquid. the average particle was size of2~4μm, evenly distributed round microbubbles by light microscope. After stored atroom temperature for24h, liquid became clear, and microbubbles became larger whilethe number was decreased.Preoperative, each parameter of testicular ultrasound contrast was no significantdifference between the experimental group and the control group(p>0.05). Afterreaching different levels of ischemia-reperfusion, the group I1’s contrast parameter PI,Slope, Area increased significantly, while TP, MTT was prolonged, which is asignificant difference compared with the group S (p <0.05). Contrast time-intensitycurve was significantly higher peak and retrusion. In group I2angiography parametersPI, Slope, Area increased further, DT/2was significantly prolonged,but TPsignificantly reduced, which is a significant difference compared with the group S,group I1(p <0.05). Contrast curve significantly increased, forward and decreasedslowly. Contrast curves was approximate a straight line in group I3. The peak of groupR angiographic time-intensity curve increased and move forward,compared with thecontrol group. With the prolongation of reperfusion, PI, Slope, Area firstly increasedand then decreased, TP firstly decreased and then increased, while MTT, DT/2showna rising trend.Preoperative, the levels of plasma vWF, NO, ET-1were not statistically differentbetween the groups (p>0.05). Each experimental group plasma vWF, NO, ET-1levelswere significantly higher than those in S group (p <0.05). Group I was with thehighest content of group I2(p <0.01). The level was firstly increased and thendecreased with the severity of ischemia. With the reperfusion time increasing, groupR’s vWF, NO, ET-1levels shown a rising trend.Testicular pathological findings: testicular interstitial vascular of Group S wereno expansion, no obvious hemorrhage and thrombosis. With the severity of ischemiain group I, testicular capillaries expansion, erythrocyte sedimentation, leakage, infiltration of inflammatory cells gradually increased. At the same time, MMP-9expression in vascular basement membrane gradually increased. Among them, thecapillaries of group I3were severely damaged with a large number of microthrombosis. Along with the reperfusion time prolonged, testicular microvascularerythrocyte sedimentation, leakage, inflammatory cell adhesion, swim, infiltrationincreased.The expression of MMP-9increased gradually.Conclusions①The method of different levels testicular ischemia-reperfusion can beconvenient, effective to establish the testis microvascular injury model.②The CEUS and quantitative analysis techniques can effectively evaluatetesticular microvascular injury.