Experimental study of three kinds of intravenous stents with different materials and different types / 中华放射学杂志

ABSTRACT

Objective To select a kind of stent with better property and spread its clinical application. Methods Three kinds of stents including “Z” type stainless steel stent(SSS), mesh Ni Ti alloy stent(AS), and gild stent(GS) were placed into dogs′ vena cava. Angiography was performed 2 weeks, 4 weeks, 8 weeks, 6 months, and 9 months after stent placements (according to the grouping time), then the animals were sacrificed to get the veins with stents for histopathology examinations (including macro pathology, microscope and scanning electron microscope). Data of displacement rate, expand rate, patency rate of stents, patency rate of tributary veins, endothelial thickness, and course of endothelialization were acquired to indicate stent application property. Measurement data were analyzed by analysis of variance and q test. Enumeration data were analyzed by ? 2 test. Ranked data were analyzed by Ridit analysis. Results The displacement rates of SSS, AS, and GS were 13 3%, 13 3%, and 7 7%, respectively(? 2=0 281, P =0 869); The incomplete expanding rates of SSS, AS, and GS were 6 7%, 46 7%, and 0.0% respectively. There was statistical difference(? 2=12 194, P 0 05); The patency rates of SSS, AS, and GS were 93 3%, 66 7%, and 84 6%, respectively. There was no statistical difference among the rates(? 2 =3 649, P =0 161). Endothelialization reached about 100% 4 weeks after the stents placements. Desquamating of GS plating layer was found 4 weeks after stent placement, surface erosion of SSS wire and AS wire was not found in 9 months. Conclusion Z type stainless steel stent has better anticoagulative capability, anticorrosive capability, and biocompatibility, and it is now an ideal intravenous stent.