食管支架的动物实验研究

目的：观察兔食管在置入金属支架后的病理变化并对临床应用提出建议。方法：对8只健康家兔食管内置入镍钛合金网状支架，分别于置入后2、4、6、8w造影、处死进行肉眼和光学显微镜观察。结果：内支架置入1w时可见黏膜下灶性慢性炎症伴轻度水肿；4w食管近支架上下两端处轻度狭窄，可见小息肉样赘生物为灶性慢性炎症伴炎性增生，支架口部黏膜过度增生，向腔内突起；6w时与4w时比较，以上改变有不同程度加重，其中1例支架下端一侧嵌入食管壁使其局部增生，与主动脉粘连；8w组于7w末死于支架处食物团滞留梗阻。结论：食管内支架再发狭窄的部位似乎以食管近支架上下的两端为主。为了防止再狭窄，支架两端口部的管径、形状、性状有待于进一步改进；支架段食管无蠕动，如无重力作用，食物易在其内滞留梗阻，因此，对良性食管狭窄的临床应用应谨慎。

Experimental Study of Esophageal Metallic Stent in Rabbits

Objective:To analyze the reaction in rabbit's esophagus after inserting a metallic nitinal stent and to get suggestions for the clinical application. Methods:The self expanding nitinal stent was placed in each of eight rabbits' esophagi. The rabbits were killed 2, 4, 6, and 8 weeks after implantation. Tissue around the stent was observed with naked eye and microscopy. Results:Chronic inflammation and edema were seen in submucous tissue 1 week after stenting. Slight stenosis occurred at the regions of two ends of stent and scattered vegetation like polyp were seen with naked eye in 4 weeks, and inflammatory cell infiltration, partial mucous polypoid hyperplasia were seen under microscopy. The pathological changes were more obvious in 6 weeks compared with in 4 weeks. The lower end of one stent was embedded in esophageal wall. Two rabbits of 8 weeks' group were died of obstruction because the food tarried in stents. Conclusions:The restructures after stenting were mainly seen at the regions of two ends of the stent. To prevent restructure the form and quality of two ends of the stent should be reformed. The section at the stent shows no peristalsis. Because of the high restenosis rate, stent implantation in benign esophageal stricture should be undertaken with care.