Dussaillant G R, Mintz G S, Pichard A D, Kent K M, Satler L F, Popma J J, Wong S C, Leon M B
Intravascular Ultrasound Imaging and Cardiac Catheterization Laboratories, Washington Hospital Center, Washington, D.C. 20010, USA.
J Am Coll Cardiol. 1995 Sep;26(3):720-4. doi: 10.1016/0735-1097(95)00249-4.
The purpose of this study was to use volumetric intravascular ultrasound analysis of Palmaz-Schatz stents to assess the in-stent restenotic process.
By reducing lesion elastic recoil and chronic arterial remodeling, stents improve the long-term results of coronary angioplasty. However, stents are prone to the development of neointimal hyperplasia. Angiographic studies of stent restenosis have suggested that these hyperplastic responses are the cause of in-stent restenosis; however, it is difficult to visualize the radiolucent Palmaz-Schatz stent by angiography. Intravascular ultrasound provides detailed cross-sectional imaging of the coronary arteries, especially the intense metallic reflection of endovascular stents.
Forty-four patients with 60 Palmaz-Schatz stents underwent intravascular ultrasound imaging at follow-up ([mean +/- SD] 8.8 +/- 7.2 months after implantation). Thirty-four stents were placed in saphenous vein grafts and 26 in native coronary arteries; 30 were placed in restenotic lesions. Intravascular ultrasound with automatic transducer pullback at 0.5 mm/s allowed measurement of stent, lumen and intimal hyperplasia cross-sectional areas at 1-mm axial increments within the stents. Using Simpson's rule, stent, lumen and intimal hyperplasia volumes were calculated. Patterns of in-stent restenosis were then identified.
Restenotic stents had smaller stent volumes (120 +/- 41 vs. 147 +/- 43 mm3, p = 0.016) and lumen volumes (62 +/- 28 vs. 118 +/- 42 mm3, p < 0.0001) but larger intimal hyperplasia volumes (58 +/- 36 vs. 29 +/- 18 mm3, p < 0.001) than nonrestenotic stents. A focal restenosis pattern was more common (20 [77%] of 26) than a diffuse restenosis pattern (6 [23%] of 26). Stents with focal restenosis and stents with diffuse restenosis had equally small stent volumes (120 +/- 44 vs. 120 +/- 31 mm3, respectively, p = NS); however, stents with diffuse restenosis had larger intimal hyperplasia volumes (84 +/- 30 vs. 50 +/- 34 mm3, p < 0.05). Focal restenosis was most commonly located at the central articulation (45%); the location of focal restenosis was related to the focal accumulation of neointimal tissue.
Stent volume and magnitude and distribution of intimal hyperplasia are important in the development of in-stent restenosis. Stent volume was smaller and intimal hyperplasia volume greater in restenotic stents. Stent restenosis is more commonly focal in nature and located at the central articulation.
本研究旨在利用对帕尔马兹-施查茨支架的容积血管内超声分析来评估支架内再狭窄过程。
通过减少病变弹性回缩和慢性动脉重塑，支架改善了冠状动脉血管成形术的长期效果。然而，支架易于发生内膜增生。支架再狭窄的血管造影研究表明，这些增生反应是支架内再狭窄的原因；然而，血管造影难以显示透X线的帕尔马兹-施查茨支架。血管内超声提供了冠状动脉的详细横截面成像，尤其是血管内支架强烈的金属反射。
44例植入60个帕尔马兹-施查茨支架的患者在随访时接受了血管内超声成像（植入后[平均±标准差]8.8±7.2个月）。34个支架置于大隐静脉移植物中，26个置于自身冠状动脉中；30个置于再狭窄病变处。以0.5mm/s的速度自动回撤换能器的血管内超声允许在支架内以1mm的轴向增量测量支架、管腔和内膜增生的横截面面积。使用辛普森法则计算支架、管腔和内膜增生的容积。然后确定支架内再狭窄的模式。
与无再狭窄的支架相比，再狭窄支架的支架容积（120±41 vs. 147±43mm³，p = 0.016）和管腔容积（62±28 vs. 118±42mm³，p < 0.0001）较小，但内膜增生容积（58±36 vs. 29±18mm³，p < 0.001）较大。局灶性再狭窄模式比弥漫性再狭窄模式更常见（26个中有20个[77%]）（26个中有6个[23%]）。局灶性再狭窄的支架和弥漫性再狭窄的支架具有同样小的支架容积（分别为120±44 vs. 120±31mm³，p = 无显著性差异）；然而，弥漫性再狭窄的支架具有更大的内膜增生容积（84±30 vs. 50±34mm³，p < 0.05）。局灶性再狭窄最常见于中央连接处（45%）；局灶性再狭窄的位置与内膜组织的局灶性积聚有关。
支架容积以及内膜增生的程度和分布在支架内再狭窄的发生中很重要。再狭窄支架的支架容积较小，内膜增生容积较大。支架再狭窄在本质上更常见于局灶性，且位于中央连接处。
