Cheng Yanping, Gasior Pawel, Xia Jing-Gang, Ramzipoor Kamal, Lee Chang, Estrada Edward A, Dokko Daniell, McGregor Jenn C, Conditt Gerard B, McAndrew Thomas, Kaluza Greg L, Granada Juan F
From the CRF-Skirball Center for Innovation, Orangeburg, NY (Y.C., P.G., J.-G.X., J.C.M., G.B.C., G.L.K., J.F.G.); Amaranth Medical, Inc, Mountain View, CA (K.R., C.L., E.A.E., D.D.); 3rd Department of Cardiology, Medical University of Silesia, Katowice, Poland (P.G.); and Cardiovascular Research Foundation, New York, NY (T.M.).
Circ Cardiovasc Interv. 2017 Jul;10(7). doi: 10.1161/CIRCINTERVENTIONS.117.005116.
Mechanical strength of bioresorbable scaffolds (BRS) is highly dependent on strut dimensions and polymer features. To date, the successful development of thin-walled BRS has been challenging. We compared the biomechanical behavior and vascular healing profile of a novel thin-walled (115 µm) sirolimus-eluting ultrahigh molecular weight amorphous poly-l-lactic acid-based BRS (APTITUDE, Amaranth Medical [AMA]) to Absorb (bioresorbable vascular scaffold [BVS]) using different experimental models.
In vitro biomechanical testing showed no fractures in the AMA-BRS when overexpanded 1.3 mm above nominal dilatation values (≈48%) and lower number of fractures on accelerated cycle testing over time (at 21 K cycles=20.0 [19.5-20.5] in BVS versus 4.0 [3.0-4.3] in AMA-BRS). In the healing response study, 35 AMA-BRS and 23 BVS were implanted in 58 coronary arteries of 23 swine and followed-up to 180 days. Scaffold strut healing was evaluated in vivo using weekly optical coherence tomography analysis. At 14 days, the AMA-BRS demonstrated a higher percentage of embedded struts (71.0% [47.6, 89.1] compared with BVS 40.3% [20.5, 63.2]; =0.01). At 21 days, uncovered struts were still present in the BVS group (3.8% [2.1, 10.2]). Histopathology revealed lower area stenosis (AMA-BRS, 21.0±6.1% versus BVS 31.0±4.5%; =0.002) in the AMA-BRS at 28 days. Neointimal thickness and inflammatory scores were comparable between both devices at 180 days.
A new generation thinned wall BRS displayed a more favorable biomechanical behavior and strut healing profile compared with BVS in normal porcine coronary arteries. This novel BRS concept has the potential to improve the clinical outcomes of current generation BRS.
生物可吸收支架（BRS）的机械强度高度依赖于支架小梁尺寸和聚合物特性。迄今为止，成功研发薄壁BRS一直具有挑战性。我们使用不同的实验模型，比较了一种新型薄壁（115 µm）西罗莫司洗脱超高分子量非晶态聚左旋乳酸基BRS（APTITUDE，苋属医疗公司[AMA]）与Absorb（生物可吸收血管支架[BVS]）的生物力学行为和血管愈合情况。
体外生物力学测试表明，AMA-BRS在超过标称扩张值1.3 mm（≈48%）过度扩张时未出现断裂，且在加速循环测试中随时间推移骨折数量较少（在21000次循环时，BVS为20.0[19.5 - 20.5]次，而AMA-BRS为4.0[3.0 - 4.3]次）。在愈合反应研究中，将35个AMA-BRS和23个BVS植入23头猪的心58条冠状动脉中，并随访180天。使用每周光学相干断层扫描分析在体内评估支架小梁愈合情况。在14天时，AMA-BRS显示出更高比例的埋入支架小梁（71.0%[47.6, 89.1]），而BVS为40.3%[20.5, 63.2]；P = 0.01）。在21天时，BVS组仍存在未覆盖的支架小梁（3.8%[2.1, 10.2]）。组织病理学显示，在28天时，AMA-BRS的面积狭窄较低（AMA-BRS为21.0±6.1%，而BVS为31.0±4.5%；P = 0.002）。在180天时，两种装置的新生内膜厚度和炎症评分相当。
与正常猪冠状动脉中的BVS相比，新一代薄壁BRS表现出更有利的生物力学行为和支架小梁愈合情况。这种新型BRS概念有可能改善当前一代BRS的临床结果。
