Biodegradation of polyether polyurethane inner insulation in bipolar pacemaker leads.
Biodegradation of polyether polyurethane inner insulation in bipolar pacemaker leads.
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双极起搏器导联中聚醚聚氨酯内绝缘材料的生物降解。
DOI：
10.1002/1097-4636(2001)58:3
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Hiltner,A
中科院分区：
文献类型：
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作者：
Wiggins,MJ;Wilkoff,B;Anderson,JM;Hiltner,A
本研究分析了几个双极同轴起搏器引线，这些引线由外部硅橡胶绝缘层和内部聚醚聚氨酯（PEU）绝缘层组成，这些引线由于电功能障碍的临床证据而被移出。使用光学显微镜（OM）和扫描电子显微镜（SEM）来确定故障原因。使用衰减全反射傅里叶变换红外显微镜 (ATR-FTIR) 分析 PEU 绝缘材料的化学降解情况。在所有引线中，硅橡胶外绝缘体均未出现物理损坏的迹象。内部 PEU 绝缘体的物理损坏是电气功能障碍的根源。 PEU 上的裂纹损害了引线中内导体线圈和外导体线圈之间的绝缘。通过扫描电镜观察发现，这些裂纹起源于内绝缘层的外表面，并向内扩展。 ATR-FTIR 分析表明，PEU 通过醚软链段的氧化而发生化学降解。此外，研究表明，PEU 外表面的化学降解更为严重。据推测，过氧化氢渗透过外部硅树脂绝缘层并分解成羟基自由基，导致 PEU 发生化学降解。外导体线圈中的金属催化过氧化氢的分解。 PEU 的化学降解也可能是由过氧化氢腐蚀外导体线圈中的金属所产生的金属离子催化的。物理损伤可能发生在导线区域，这些区域受到炎症细胞产生的较高过氧化氢浓度以及由于体内运动（包括但不限于心脏运动）造成的高程度和高应变率的影响。化学降解和物理损坏可能对绝缘失效产生协同影响，因为随着化学降解的进行，聚合物表面变得易碎并且更容易受到物理损坏。随着物理损坏的继续，裂纹蔓延到未受影响的块体中，使其暴露于氧化剂中。 © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 302–307, 2001
Several bipolar coaxial pacemaker leads, composed of an outer silicone rubber insulation and an inner polyether polyurethane (PEU) insulation, which were explanted due to clinical evidence of electrical dysfunction, were analyzed in this study. Optical microscopy (OM) and scanning electron microscopy (SEM) were used to determine the cause of failure. Attenuated total reflectance‐Fourier transform infrared microscopy (ATR‐FTIR) was used to analyze the PEU insulation for chemical degradation. In all leads, the silicone rubber outer insulation showed no signs of physical damage. Physical damage to the inner PEU insulation was the source of electrical dysfunction. Cracks through the PEU compromised the insulation between the inner and outer conductor coils in the lead. It was observed with SEM that these cracks originated on the outer surface of the inner insulation and progressed inward. ATR‐FTIR analysis showed that the PEU had chemically degraded via oxidation of the ether soft segment. Furthermore, it was revealed that chemical degradation was more advanced on the outer surface of the PEU. It was hypothesized that hydrogen peroxide permeated through the outer silicone insulation and decomposed into hydroxyl radicals that caused the chemical degradation of PEU. The metal in the outer conductor coil catalyzed the decomposition of the hydrogen peroxide. Chemical degradation of the PEU could also have been catalyzed by metal ions created from the corrosion of the metal in the outer conductor coil by hydrogen peroxide. Physical damage probably occurred in regions of the leads that were subjected to a higher hydrogen peroxide concentration from inflammatory cells and high degrees and rates of strain due to intercorporeal movement, including, but not limited to, cardiac movement. Chemical degradation and physical damage probably had a synergistic affect on failure of the insulation, in that as chemical degradation proceeded, the polymer surface became brittle and more susceptible to physical damage. As physical damage proceeded, cracks propagated into the unaffected bulk, exposing it to oxidants. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 302–307, 2001