细粒棘球蚴囊内容物致肺栓塞的实验观察

An experimental study on pulmonary embolism caused by echinococcus granulosus cyst

目的建立囊型包虫病肺梗塞的动物模型。方法取羊肝脏包虫囊内容物、分离出囊砂及澄清囊液,囊沙与囊液配成5％的混悬液。取21只家兔,随机分为三组:每组 n=7,Ⅰ组(生理盐水),Ⅱ组(澄清囊液),Ⅲ组(囊沙混悬液)。每只家兔均经股动静脉置入导管,依照上述分组按2 ml/kg 分别经静脉导管缓注生理盐水、澄清囊液、囊砂混悬液。于注射后5,10,30,60 min 取动脉血动态监测 MAP、血气指标。测定完成后经静脉缓注^(99m)Tc-MMA 2 ml,10 min 后扫描成像,观察结束后处死动物,取肺脏行光镜、电镜检查。结果Ⅲ组在注射后 MAP、血气均出现明显的降低,并低于Ⅰ组(P<0.05),而Ⅱ组虽有降低(P<0.05),但与Ⅲ组相比较下降程度小;ECT 显示Ⅲ组动物肺组织呈放射性缺损,Ⅱ组放射性减弱;病理:Ⅲ组可见头节广泛栓塞于肺小、微小动脉,呈“ARDS 样”改变,Ⅱ组表现为肺淤血、水肿及炎性细胞浸润。结论Ⅲ组动物基本能够模拟出囊型包虫病肺梗塞的临床表现,其中囊液中有形成分在肺梗塞中起主要作用。

Objective To establish an animal model of pulmonary embolism caused by Echino- coccus granulosus (E.g) cyst.Methods Fresh clear cyst fluid and sand-containing cyst fluid were i- solated from E.g cyst in the sheep liver.A 5% suspension was made with these two kinds of fluid. Twenty-one rabbits were randomized into the following 3 groups:Group Ⅰ-saline group (n=7); group Ⅱ-clear cyst fluid group (n=7) and group Ⅲ-sand-containing cyst fluid group (n=7).Opera- tions were performed in each animal to place a femoral artery catheter and a femoral vein catheter for infusion as well as specimen and data collection.Saline,clear cyst fluid or sand-containing cyst fluid was respectively given to rabbits in the 3 groups at a dose of 3 ml/kg body weight through the femoral vein catheter.MAP and blood gas were observed from artery blood at the 5th,10th,30th and 60th minute after the infusion.Then 2 ml ^(99m)Tc-MMA was slowly injected through the vein and scanning image was obtained 10 minutes later.After the observation,all the animals were killed and their lungs harvested for histological examination by light and electron microscopy.Results Remarkable decline of MAP and PaO_2 were found in group Ⅲ as compared with group Ⅰ (P<0.05).The same change was seen in group Ⅱ (P<0.05),but the level of decline was lower.ECT examination showed radio- activity defection of lungs in group Ⅲ and radioactivity weakening of the lungs in group Ⅱ.Pathologi- cal examination revealed that in group Ⅲ there were“ARDS-like”changes including E.g protoscolex embolism in small and minimal pulmonary arteries.Furthermore,blood clot,edema and inflammation cells invasion of the pulmonary tissue were found in group Ⅱ.Conclusions Animals in group Ⅲ can basically simulate the clinical situation of pulmonary embolism caused by E.g cyst content.The sand contained in cyst fluid plays an important role in this kind of pulmonary embolism.