Sumikura Hirohito, Nakayama Yasuhide, Ohnuma Kentaro, Takewa Yoshiaki, Tatsumi Eisuke
Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
Artif Organs. 2014 Apr;38(4):282-9. doi: 10.1111/aor.12173. Epub 2013 Nov 14.
We have used in-body tissue architecture technology to develop an autologous valved conduit with intact sinuses of Valsalva (biovalve). In this study, we fabricated three different forms of biovalves and evaluated their function in vitro using a mock circulation model to determine the optimal biovalve form for aortic valve replacement. A cylindrical mold for biovalve organization was placed in a dorsal subcutaneous pouch of a goat, and the implant that was encapsulated with connective tissue was extracted 2 months later. The cylindrical mold was removed to obtain the biovalve (16 mm inside diameter) that consisted of pure connective tissue. The biovalve was connected to a pulsatile mock circulation system in the aortic valve position. The function of the three biovalves (biovalve A: normal leaflets with the sinuses of Valsalva; biovalve B: extended leaflets with the sinuses of Valsalva; biovalve C: extended leaflets without the sinuses of Valsalva) was examined under pulsatile flow conditions using saline. In addition, the mock circuit was operated continuously for 40 days to evaluate the durability of biovalve C. The regurgitation rate (expressed as a percent of the mean aortic flow rate during diastole) was 46% for biovalve A but only 3% for biovalves B and C. The durability test demonstrated that even after biovalve C pulsated more than four million times (heart rate, 70 bpm; mean flow rate, 5.0 L/min; mean aortic pressure, 92 mm Hg), stable continuous operation was possible without excessive reduction of the flow rate or bursting. The developed biovalve demonstrated good function and durability in this initial in vitro study.
我们利用体内组织结构技术开发了一种带有完整主动脉窦的自体带瓣管道（生物瓣膜）。在本研究中，我们制作了三种不同形式的生物瓣膜，并使用模拟循环模型在体外评估它们的功能，以确定用于主动脉瓣置换的最佳生物瓣膜形式。将用于生物瓣膜构建的圆柱形模具置于山羊背部皮下袋中，2个月后取出包裹有结缔组织的植入物。移除圆柱形模具以获得由纯结缔组织构成的生物瓣膜（内径16毫米）。将该生物瓣膜连接到主动脉瓣位置的搏动性模拟循环系统。在搏动血流条件下使用盐水检查三种生物瓣膜（生物瓣膜A：带有主动脉窦的正常瓣叶；生物瓣膜B：带有主动脉窦的延长瓣叶；生物瓣膜C：没有主动脉窦的延长瓣叶）的功能。此外，使模拟回路连续运行40天以评估生物瓣膜C的耐久性。生物瓣膜A的反流率（以舒张期平均主动脉流速的百分比表示）为46%，而生物瓣膜B和C仅为3%。耐久性测试表明，即使生物瓣膜C搏动超过400万次（心率70次/分钟；平均流速5.0升/分钟；平均主动脉压92毫米汞柱）后，仍可实现稳定的连续运行，且流速不会过度降低或破裂。在这项初步的体外研究中，所开发的生物瓣膜显示出良好的功能和耐久性。
