普通超声及超声造影检测兔胆道缺血模型胆道异常的可行性研究

目的探讨普通超声及超声造影应用于检测兔胆道缺血模型胆道异常的可行性。方法将20只健康新西兰兔随机分为两组,对照组及肝动脉和胆总管联合阻断2h(HBO2h)组(各10只)。HBO2h组用无损伤动脉夹阻断肝动脉及胆总管下段2h后去除动脉夹制作胆道缺血模型,对照组不进行任何手术处理。术后5d两组实验兔先后采用普通超声、超声造影观察胆总管-左叶胆管情况,然后处死动物取胆总管-左叶胆管标本行苏木素-伊红(HE)染色,对胆管组织缺血损伤程度进行评分,CD34免疫组织化学染色后行微血管密度(microvascular density,MVD)定量分析。结果普通超声表现:对照组门静脉管径/胆管管径比值为3.47±0.23,所有胆管(100%)均表现为管壁连续性好、无增厚,管腔清晰;HBO2h组胆管明显扩张,门静脉管径/胆管管径比值为1.25±0.42,与正常组比较差异有统计学意义(P<0.01);所有胆管均表现为管壁毛糙、增厚。超声造影表现:对照组所有胆管壁(100%)较肝实质提早增强,动脉期胆管壁呈细线状高增强,门静脉期及延迟期呈等增强;HBO2h组中60%(6/10)表现为动脉期胆管壁呈增强水平明显降低,门静脉期及延迟期呈低增强;40%(4/10)表现为增强扫描全过程均呈无增强;与对照组相比,HBO2h组各时相胆管壁增强表现差异均有统计学意义(均为P<0.05)。病理学表现:对照组胆管黏膜上皮细胞和黏膜下腺体上皮细胞呈柱状,排列紧密、完整,无上皮细胞变性、坏死、脱落等,胆管损伤评分为0分,MVD为(6.1±2.5)个。HBO2h组胆管壁增厚,胆管黏膜上皮细胞及黏膜下腺体上皮变性、坏死、脱落,管壁炎症细胞浸润,胆管损伤评分为(2.1±0.6)分,MVD为(2.2±1.6)个,与对照组比较差异有统计学意义(均为P<0.01)。结论普通超声及超声造影能较早发现胆道缺血兔模型的胆道异常,为缺血型胆道病变动物实验研究提供了一种简便、无创、动态监测病程发展的有效手段。

Feasibility of accessing the abnormal bile duct in biliary ischemia of rabbit model by using conventional and contrast-enhanced ultrasonography

Objective To investigate the feasibility of assessing the abnormal bile duct in biliary ischemia of rabbit model by using conventional ultrasonography （ US ） and contrast-enhanced ultrasonography （CEUS）. Methods Twenty New Zealand rabbits were randomly divided into control group and operation group by blocking hepatic artery and common bile duct for 2 hours （ HBO 2 h group ） （ 10 rabbits in each group）. The hepatic artery （HA） and common bile duct （CBD） of the rabbits in the HBO 2 h group were clamped combined with smooth nonserrated vessel clips for 2 hours, while the normal group was performed none of operation. The condition of common and left lobe bile duct in rabbits was observed by US and CEUS at day 5 after operation. Then the rabbits were sacrificed for specimens of common and left lobe bile duct. The scores of ischemia injury was evaluated by hematoxylin-eosin （HE） staining. CD34 immunohistochemical stain was used for quantitative analysis of microvascular density （MVD）. Results （ 1 ） The appearance of US ： the bile duct of normal group showed a portal to biliary caliber ratio of 3.47 -＋ 0. 23, intact and non-thickened wall and clear lumen ; the HBO 2 h group showed a portal to biliary caliber ratio of 1.25 ＋_ O. 42, thickened wall and dilated lumen, there was significantly different between two groups （P 〈0.01 ）. （2） The appearance of CEUS： The duct wall of normal group presented hyper-enhancing at arterial phase and persistent iso-enhancing at portal and late phases; the HBO 2 h group presented lowly hyper-enhancing at arterial phase and hypo-enhancing at portal and late phases （60%, 6/10） or non-enhancing at three phases （40%, 4/10） compared with the normal group （ all in P 〈 0. 05）. （3） The appearance of pathology ： The epithelium of normal biliary duct was intact without degeneration, necrosis or loss. The patho-morphological score was 0 and the MVD was 6. 1 ＋ 2. 5. The HBO 2 h group showed thickened biliary wall, epithelium degeneration, necrosis and loss, and inflammatory cell infiltration. The patho-morphologica] score was 2.1 ＋ 0.6 and the MVD was 2.2 ＋- 1.6, which were significantly different compared with those in normal group （ all in P 〈 0. 01 ）. Conclusions US and CEUS can discover the abnormal bile duct in biliary ischemia of rabbit model, providing an effective way with convenience, non-invasiveness and monitoring the development of biliary ischemia dynamically for research on animal model with ischemic-type biliary lesion.