Tominaga R, Harasaki H, Sutton C, Emoto H, Kambic H, Hollman J
Department of Biomedical Engineering, Cleveland Clinic Foundation, Ohio.
Am Heart J. 1993 Nov;126(5):1049-58. doi: 10.1016/0002-8703(93)90654-r.
We investigated the effect of serum cholesterol level and stent design on the restenosis rate within the stent after balloon angioplasty and stent implantation using atherosclerotic rabbits. Two types of nickel/titanium stents with gaps (open stent) and without gaps (closed stent) between the wire coils were implanted into the aorta of the rabbits 10 weeks after atherosclerosis had been induced using a standard high cholesterol diet and balloon abrasion. Each rabbit had an open stent and a closed stent implanted into the infrarenal abdominal aorta. Between these two stents a control segment of the aorta was treated with angioplasty alone. The animals were divided into two groups according to the diet protocol as follows: in group I (n = 9) a high cholesterol diet was stopped after stent implantation; in group II (n = 10) a high cholesterol diet was maintained after stent implantation. Digital subtraction angiograms were obtained every 4 weeks for up to 24 weeks and the narrowest diameter of the arterial segments within each stent and in the segment between stents was measured. The diameter narrowing within the closed stent was greater in the high cholesterol group compared with the low cholesterol group: 12 weeks (2.57 +/- 0.09 mm in group I vs 2.14 +/- 0.15 mm in group II, mean +/- S.E., p < 0.05); 16 weeks (2.55 +/- 0.09 mm vs 2.14 +/- 0.12 mm, p < 0.05); 20 weeks (2.59 +/- 0.06 mm vs 1.98 +/- 0.12 mm, p < 0.01); and 24 weeks (2.45 +/- 0.11 mm vs 2.01 +/- 0.11 mm, p < 0.05). No significant differences in the narrowest diameter of the arterial segments were observed between high and low cholesterol groups in the angioplasty alone areas or within the open stents. There was a significant difference in the narrowest diameter between stents with versus those without gaps (at 12, 16, and 20 weeks poststenting in group I and at 4, 8, 12, 16, 20, and 24 weeks in group II). Thus the stent with the least metal is correlated with less stenosis and intimal hyperplasia. From these data we conclude that both stent design and serum cholesterol are important factors for restenosis after stent implantation.
我们使用动脉粥样硬化兔研究了血清胆固醇水平和支架设计对球囊血管成形术和支架植入术后支架内再狭窄率的影响。在使用标准高胆固醇饮食和球囊磨损诱导动脉粥样硬化10周后，将两种类型的镍钛合金支架植入兔主动脉，一种是线圈之间有间隙的（开放式支架），另一种是没有间隙的（封闭式支架）。每只兔在肾下腹主动脉植入一个开放式支架和一个封闭式支架。在这两个支架之间，对主动脉的一个对照节段仅进行血管成形术治疗。根据饮食方案将动物分为两组：第一组（n = 9）在支架植入后停止高胆固醇饮食；第二组（n = 10）在支架植入后维持高胆固醇饮食。每4周进行一次数字减影血管造影，持续24周，测量每个支架内及支架间节段动脉的最窄直径。与低胆固醇组相比，高胆固醇组封闭式支架内的直径狭窄更明显：12周时（第一组为2.57±0.09mm，第二组为2.14±0.15mm，平均值±标准误，p<0.05）；16周时（2.55±0.09mm对2.14±0.12mm，p<0.05）；20周时（2.59±0.06mm对1.98±0.12mm，p<0.01）；24周时（2.45±0.11mm对2.01±0.11mm，p<0.05）。在仅进行血管成形术的区域或开放式支架内，高胆固醇组和低胆固醇组动脉节段的最窄直径没有显著差异。有间隙支架和无间隙支架的最窄直径存在显著差异（第一组在支架植入后12、16和20周，第二组在4、8、12、16、20和24周）。因此，金属含量最少的支架与较少的狭窄和内膜增生相关。根据这些数据我们得出结论，支架设计和血清胆固醇都是支架植入后再狭窄的重要因素。
