放射性纳米材料食管支架的动物组织学实验观察

Animal experiment on ^(188)Re-radioactive nanometre particle esophageal stent

目的研究放射性纳米材料食管支架的作用机制和临床应用前景。方法使用镍钛合金复层膜Z型食管支架,负载纳米材料交联的188Re放射性核素分别放置于约克品系猪的食管腔内,并固定支架。结果8只实验猪及2只对照猪安放的支架均成功进入预定位置,支架扩张良好,食管未发生穿孔、出血等并发症。食管支架放置3h后实验猪开始正常进食,未出现呛咳现象。实验猪在置入放射活度128MBq支架7d后病理学检查发现食管黏膜、黏膜下层炎性细胞浸润、充血水肿,21d后部分标本可见黏膜血管壁增厚,少量纤维组织增生。置入放射活度259MBq支架7d后病理学发现黏膜、黏膜下层广泛炎性细胞浸润、肌层水肿及片状坏死,21d后出现修复性组织纤维增生。对照组则未发现食管机械性病理损伤,定期对猪粪便的检测也未发现放射性核素的泄漏,且无支架移位。结论放射性纳米材料食管支架既能扩张进食通道,又可通过支架负载的放射性核素对靶组织持续低剂量放射治疗。放射活度128MBq支架对食管肌肉组织放射损伤较少,晚期反应有待进一步研究。

Objective To investigate the mechanism and clinical reliability of applying 188 Re radioactive nanometre particle esophageal stent. Methods An elastic meshed esophageal stent made of double membranous nickel titanium alloy and loaded with 188 Re radioactive nanometre particles was used . The stent was introduced into the esophagus of eight experimental pigs and fixed in place.Two pigs served as controls.With the pig aneasthetized, the stent with good expandability was placed in the proper position.Radioactive ?MBq was applied to the 8 experiment pigs while the two control pigs received only the stent without the radioactive material.Three hours after the insertion of the stent,the pigs were allowed to feed,without any choking observed. Results Seven days after the treatment of pathologic experiment pigs showed infla?mmatory celluar infilfration,congestion and edema in the mucosa and submucous layer.After 21 days,some parts of the esophageal mucosa showed thickening of the vascular layer of the blood vessels and scanty fibrous hyperplasia.Seven days after application of larger dose of 259?MBq stent,pathology examination carried out in the experiment pigs showed extensive infla?mmatory cellular infilfration,edema and congestion in the muscles and submucosa, and patch like necrosis.Twenty one days after application,repairing fibrous hyperplasia appeared.In the control pigs,not even any traumatic damage was observed.Periodic checking of the stool did not show any leakage of radioactivity and there was no displacement of the stents as confirmed by X ray exam.Conclusions The stent is effective to maintain an unobstructed passage of food . The loaded radioactive particles can be concentrated in the target area and adjusted by a body surface magnetic modulation and inhibit the intraluminal epithelial growth of esophageal mucosa without any severe radiation reaction or damage. It is quite promising to resolve the obstruction of advanced esophageal cancer with radioactive self expandable metallic stent.