Miyakita H, O'Briain D S, Puri P
Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin, Ireland.
Eur Urol. 1998 Sep;34(3):233-6. doi: 10.1159/000019720.
Polytetrafluoroethylene (PTFE) paste has been used for over 30 years to treat urinary incontinence and for 14 years to treat vesicoureteral reflux with little reported morbidity. Some investigators have been concerned by the use of PTFE as the implanted substance, because migration of PTFE particles from the site of injection in the periurethral and periureteral regions to the lungs and brain has been reported in animal studies. We injected PTFE paste intravascularly in dogs in order to investigate its effect on brain parenchyma.
A total of 12 mongrel dogs, weighing 11.5-17.5 kg, were divided into four groups. Group 1 (n = 3): injection of 0.5 ml of PTFE paste suspended in 50 ml of saline into a peripheral vein once a week for 4 weeks. Group 2 (n = 3): injection of 50 ml of saline into a peripheral vein once a week for 4 weeks as controls. Group 3 (n = 3): one injection of 0.1 ml of PTFE paste suspended in 20 ml of saline into the right carotid artery. Group 4 (n = 3): one injection of 20 ml of saline into the right carotid artery as controls. After an interval of 6 months, all animals were sacrificed and the lungs and brain removed. Brain from 1 animal in each group was dissolved in sodium hypochlorite solution, the resulting organ suspension was centrifuged, and the smear preparations of the precipitate examined by polarized light microscopy, scanning electron microscopy, and X-ray microanalysis. Brains from 2 animals in each group were fixed in formalin solutions, 6-micrometer sections were cut and stained with haematoxylin and eosin, Cajal stain for Purkinje fibre, and Luxol fast blue stain for myelin, and glial fibrillary acidic protein immunohistochemistry was carried for astrocytes using monoclonal mouse anti-GFAP (glial fibrillary acidic protein) at a dilution of 1:50 with an avidin-biotin-peroxidase complex method.
PTFE particles were seen in the cerebral vessels in only those animals who had PTFE injected into the right carotid artery. The haematoxylin and eosin staining showed PTFE particles in vessels with focal foreign-body reaction, but no infarction. Luxol fast blue staining showed no demyelination around vessels containing the particles and the parenchyma. Cajal staining demonstrated no abnormality of nerve fibres, and there was no astrocytosis using GFAP immunohistochemical staining.
Our findings indicate that following intravenous injection, there was no evidence of migration of PTFE to the brain. Small quantities of PTFE injected into the carotid arteries were associated with local foreign-body reaction, but no brain parenchymal tissue damage was found.
聚四氟乙烯（PTFE）糊剂已用于治疗尿失禁30多年，用于治疗膀胱输尿管反流14年，据报道其发病率很低。一些研究人员对使用PTFE作为植入物质表示担忧，因为在动物研究中已报道PTFE颗粒会从尿道周围和输尿管周围区域的注射部位迁移至肺和脑。我们通过向犬血管内注射PTFE糊剂，以研究其对脑实质的影响。
将12只体重为11.5 - 17.5 kg的杂种犬分为四组。第1组（n = 3）：每周一次将0.5 ml悬浮于50 ml生理盐水中的PTFE糊剂注入外周静脉，共注射4周。第2组（n = 3）：作为对照，每周一次将50 ml生理盐水注入外周静脉，共注射4周。第3组（n = 3）：将0.1 ml悬浮于20 ml生理盐水中的PTFE糊剂一次性注入右颈动脉。第4组（n = 3）：作为对照，将20 ml生理盐水一次性注入右颈动脉。间隔6个月后，处死所有动物，取出肺和脑。每组取1只动物的脑，将其溶解于次氯酸钠溶液中，所得器官悬液离心，沉淀物涂片经偏振光显微镜、扫描电子显微镜和X射线微分析检查。每组取2只动物的脑，用福尔马林溶液固定，切成6微米厚的切片，进行苏木精-伊红染色、用于浦肯野纤维的 Cajal 染色和用于髓磷脂的 Luxol 固蓝染色，并用稀释度为1:50的单克隆小鼠抗胶质纤维酸性蛋白（GFAP）通过抗生物素蛋白-生物素-过氧化物酶复合物法对星形胶质细胞进行胶质纤维酸性蛋白免疫组织化学染色。
仅在那些将PTFE注入右颈动脉的动物的脑血管中发现了PTFE颗粒。苏木精-伊红染色显示血管内有PTFE颗粒，并伴有局灶性异物反应，但无梗死。Luxol固蓝染色显示含有颗粒的血管周围和实质内无脱髓鞘现象。Cajal染色显示神经纤维无异常，GFAP免疫组织化学染色未发现星形细胞增生。
我们的研究结果表明静脉注射后，没有证据表明PTFE迁移至脑。注入颈动脉的少量PTFE与局部异物反应有关，但未发现脑实质组织损伤。
