More R B
CarboMedics, Austin, TX 78752.
Med Prog Technol. 1994;20(3-4):195-200.
Two retrieved long-term human implant Björk-Shiley valve prostheses were examined for wear. The prostheses were retrieved at necropsy from a double implant patient that had died from causes unrelated to the valves twelve years post implantation. Both prostheses were the Björk-Shiley conical tilting disc type heart valves with Haynes 25 alloy orifice and a Pyrolite Carbon disc. A size 21 mm valve had been implanted in the aortic position and a size 27 mm valve had been implanted in the mitral position. Wear had occurred on the valves in regions of mutual contact between the disc and orifice struts during valve opening and closing. Wear mark depths and types were consistent with previous observations on Pyrolite Carbon Björk-Shiley and Lillehi-Kaster prostheses. No evidence of cavitation nor strut fatigue damage was observed on either valve prosthesis. Wear that occurred on the valves was insignificant and of no consequence to valve function.
对两枚回收的长期植入人体的 Björk-Shiley 瓣膜假体进行了磨损检查。这些假体是在尸检时从一名双瓣膜植入患者身上取出的，该患者在植入瓣膜十二年后死于与瓣膜无关的原因。两枚假体均为带有 Haynes 25 合金孔口和 Pyrolite 碳盘的 Björk-Shiley 锥形倾斜盘式心脏瓣膜。一枚 21 毫米大小的瓣膜植入了主动脉位置，一枚 27 毫米大小的瓣膜植入了二尖瓣位置。在瓣膜开闭过程中，瓣膜上圆盘与孔口支柱相互接触的区域出现了磨损。磨损痕迹的深度和类型与先前对 Pyrolite 碳 Björk-Shiley 和 Lillehi-Kaster 假体的观察结果一致。在两枚瓣膜假体上均未观察到气蚀和支柱疲劳损伤的迹象。瓣膜上出现的磨损并不明显，对瓣膜功能也没有影响。
