RÉSUMÉ
BACKGROUND:With the development of the basic research and clinical application, as wel as stent materials, endovascular stent therapy has been widely used in cerebrovascular disease treatment. OBJECTIVE:To review the characteristics and clinical application of several kinds of stent materials. METHODS: A computer-based search of CNKI, Wanfang, and PubMed databases was performed for relevant articles published before Match 2014 using the keywords of “cerebrovascular disease, stents, biocompatibility” in Chinese and English. RESULTS AND CONCLUSION:According to release methods, cerebrovascular stents can be divided into baloon expanding stents and self-expanding stents. The original materials are mainly bare metal materials, made of memory aloy, medical stainless steel, tantalum, cobalt, nickel and titanium aloy. Because the metalic stent after implantation wil release metal ions that are easy to cause thrombosis and the restenosis rate is high, the coating stents and covered stents appear. Perioperative complications of stent implantation mainly include excessive perfusion syndrome, acute thrombosis, and vascular rupture and distal vascular embolization, vasospasm and puncture-related complications; the long-term complications are mainly restenosis after stent implantation. With the continuous improvement of stent materials and production techniques, vascular stent implantation wil be more safe and effective.
RÉSUMÉ
BACKGROUND: Biliary ischemia-reperfusion injury is one of the main reasons for the injury bile duct following liver transplantation, liver resection and hepatic artery thrombosis after chemotherapy. However, nothing has been decided yet concerning liver can tolerate long intrahepatic bile ducts ischemia under normal temperature. OBJECTIVE: To use the rabbit biliary ischemia-reperfusion injury, model, analyze the rabbit intrahepatic bile ducts ischemia security time. METHODS: Rabbits were randomly divided into sham operation, hepatic artery and common bile duct joint blocking 1.5, 2, 2.5, 3 h groups. Sham operation group only free common bile duct, hepatic artery and portal vein. Hepatic artery and common bile duct joint blocking 1.5, 2, 2.5, 3 h groups, left and right hepatic duct openings superior margin was clamped using artery clamps, and hepatic artery, common bile duct and loose connective tissue were occluded. Following 1.5, 2, 2.5 and 3 hours, artery clamps were removed to recover hepatic artery or biliary tract blood flow. After a week, animal survival was calculated and liver function was tested. RESULTS AND CONCLUSION: None animals in the sham operation and hepatic artery and common bile duct joint blocking 1.5 hour groups died;survival rate was 87.5% following 2 hours of blocking. Animal survival rate was decreased gradually with prolonged blocking time of blood flow. These indicated that the maximum safety time of blocking biliary duct blood flow was 2 hours. Pathological and histological changes were mild within 2 hours of blocking, mainly presenting cell edema and inflammatory cell infiltration, and necrotic focus was punctiform or fragmentis, reversible. While ischemia above 2 hours, bile duct epithelial necrotic shape was significant. The obvious, hepatic necrosis was multifocal, flake, irreversible damage. Histological change also confirmed that 2 hours may be maximum security limitation of rabbit tolerance intrahepatic bile duct flow blocking under normal temperature.