食管支架在兔食管中的实验研究

Experimental study of esophageal metallic stent in rabbits

目的 观察金属支架在兔食管中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于镍钛合金网状支架 ,分别于置入后 2、4、6、8周造影观察 ;处死实验动物 ,观察食管组织学变化。结果 内支架置入 2周时 ,可见黏膜下灶性慢性炎症伴轻度水肿 ;4周 ,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 ;6周时上述改变有不同程度加重 ,其中 1只动物支架下端一侧嵌入食管壁使其局部增生 ,与主动脉粘连 ;8周组于 7周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支架的上下两端食管为主。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 ;食管内支架再发狭窄率较高 ,因此 ,对良性食管狭窄的临床应用应谨慎。

Objective To analyze the reaction in rabbit's esophagus after inserting metallic nitinal stent and obtaining suggestion for the clinical application.Methods The selfexpanding nitinal stent was placed in each of eight rabbits's esophagus. The rabbits were killed at 2,4,6,8 weeks after implantation. Tissue around the stent was investigated with naked eye and microscopy. Results Chronic inflammation and edema were seen in the submucous tissue 2 week after stenting. Slight stenosis occurred at the regions of two ends of the stent and scattered vegetations like polyp were seen with naked eye at 4 weeks, with inflammatory cell infiltration, partial mucous polypoid hyperplasia under microscopy. The pathological changes were more obvious at 6 weeks comparing with the 4 weeks. The lower end of one stent was embedded in esophageal wall. Two rabbits of 8 weeks' group died of obstruction with food tarried inside the stents.Conclusions The restenosis after stenting were mainly seen at the region of terminals of stent. Thus reformation of stent should be taken place urgently especially at the terminals for the prevention of restenosis.