胆管内照射支架应用的实验研究

目的探讨实验犬胆管内照射支架置入的可行性和安全性。方法选择比格犬36只,分成实验组27只和对照组9只。实验组按放置粒子剂量分为A、B和C亚组,每组9只。A组每颗粒子剂量为11.1 MBq,放置2颗;B组为22.2 MBq,放置2颗;C组为33.3 MBq,放置2颗。采用经皮胆囊穿刺胆总管支架置入法,手术前后定期复查血液生化指标,并于术后2、4、6个月,各组分别取实验犬各3只,摄肝区平片、CT扫描及ECT粒子显像等影像方法观察内照射支架。实验犬处死后取支架及周围组织标本,分别行肉眼、光镜及电镜观察。结果 36只实验犬胆总管内照射支架均释放到位,释放过程顺利,未出现放射粒子脱落现象。术后复查血象和免疫指标未见明显变化。ECT复查未发现放射源泄漏。解剖实验犬未发现胆管穿孔、出血等并发症。6个月时实验组粒子附近胆管壁增厚最明显,与对照组比较差异有统计学意义(P<0.05),实验组的各亚组之间差异无统计学意义(P>0.05)。实验组和对照组胆总管内径在观察期内均表现为随时间延长管腔逐渐变窄,6个月时各实验组管腔内径与对照组比较差异无统计学意义(P>0.05)。6个月内实验组支架周围的肝脏、胰腺、门静脉及十二指肠与对照组肉眼、光镜所见基本一致。电镜下仅表现为胆管壁肌层增生、成纤维细胞增生等。结论实验犬胆总管内照射支架置入术可行、安全,其对犬胆管及其周围的正常脏器组织造成损伤轻微。

The implantation of irradiation stent in biliary duct: an experimental study in animals

Objective To investigate the feasibility and safety of the placement of irradiation stent in biliary duct in beagles.Methods A total of 36 experimental beagles were randomly divided into study group(n = 27) and control group(n = 9).The beagles in the study group were equally subdivided into three subgroups(group A,B and C) with nine beagles in each subgroup.Two 0.3 mci(11.1 MBq) particles were used in the beagles of group A,while two 0.6 mci(22.2 MBq) particles and two 0.9 mci(33.3 MBq) particles were employed in the beagles of group B and group C,respectively.All the irradiation stents were placed into the common bile duct through percutaneous transhepatic biliary puncture.The biochemical indexes of blood were regularly checked before and after the surgery.The plain radiography of hepatic region,CT scan and ECT imaging were performed in 3 beagles of each subgroup and control group at 2,4 and 6 months after the treatment in order to observe the condition of the inserted biliary stent.All the experimental beagles were sacrificed.The stents with the surrounding tissues were collected and sent for macroscopic,optical and electronic microscopic examinations.Results The irradiation stents were successfully placed into the common bile duct in all 36 beagles,no dropping of 125I seeds occurred.No marked changes of haemogram and immune index were observed after the procedure.No radioactive source leaking was detected by ECT.Autopsy found no severe complications such as bile duct perforation,bleeding,etc.At six months,in the beagles of the study group the biliary duct wall near to 125I seeds became distinctly thickened.The difference in the wall thickness between the study group and the control group was statistically significant(P < 0.05),but no significant difference in the wall thickness existed among three subgroups(P > 0.05).During the observation period of six months,the inside diameter of the common bile duct became gradually narrowed in both study group and control group,and no significant difference in the inside diameter of the common bile duct existed among the subgroups and the control group(P > 0.05).The macroscopic and optical findings of the liver,pancreas,portal vein and duodenum in the vicinity of the stent were basically the same in both the study group and the control group.Electronic microscopic examination revealed muscular layer hyperplasia and fibroblast hyperplasia of the bile duct wall.Conclusion The implantation of irradiation stent in biliary duct in experimental dogs is technically feasible and safe,although the procedure may probably cause some minor damage to the biliary duct and surrounding organs.