Fischlein T, Schütz A, Uhlig A, Frey R, Krupa W, Babic R, Thiery J, Reichart B
Department of Cardiac Surgery, University of Munich, Germany.
Eur J Cardiothorac Surg. 1994;8(8):425-30. doi: 10.1016/1010-7940(94)90084-1.
Since it has been suggested that the leaflet tissue viability influences durability after homologous valve replacement, we compared different harvest and preservation techniques in order to examine the quality and smoothness of homograft conservation. We analyzed human aortic and pulmonary valve leaflets obtained from 'heart-beating donors' (HBD) during heart transplantation and from 'non-heart-beating donors' (NHBD) during coroner's autopsies. Valves were either cryopreserved in liquid nitrogen or stored at 4 degrees C in nutrient medium similar to the procedure reported in our protocols of the homograft bank system. All grafts from NHBD had been antibiotically sterilized for 3 days beforehand. Morphological observations were made using light and electron microscopy and, in order to characterize the endothelial cell viability, a non-radioactive cell proliferation assay was used. The PGI2 secretion of the remaining endothelium was defined as the 6-keto-prostaglandin F1 alpha metabolite by an enzyme immunoassay. Observations in the scanning electron microscope revealed that, after cryopreservation, homografts show an almost confluent endothelium when processed within 24 h after harvest from HBD, but lack endothelial cells when obtained from NHBD. Cryopreserved grafts from NHBD exhibited an altered tissue structure with edema and vacuolization within the spongiosa of the leaflets as well as irreversible cell damage when examined under the light and transmission electron microscope. That the metabolic activity of HBD homografts was maintained was confirmed by proven PGI2 secretion (6150 +/- 1200 pg/3 ml M199 after cryopreservation), whereas specimens from NHBD showed a reduced (1950 +/- 730 pg/3 ml M199) and, after cryopreservation, almost no release (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
由于有人提出瓣叶组织活力会影响同种瓣膜置换术后的耐久性，我们比较了不同的获取和保存技术，以检验同种移植物保存的质量和顺滑度。我们分析了在心脏移植期间从“心跳供体”（HBD）以及在法医尸检期间从“非心跳供体”（NHBD）获取的人主动脉瓣和肺动脉瓣叶。瓣膜要么在液氮中冷冻保存，要么在类似于我们同种移植物库系统方案中所报告的程序那样的营养培养基中于4℃保存。所有来自NHBD的移植物事先都用抗生素消毒了3天。使用光学显微镜和电子显微镜进行形态学观察，并且为了表征内皮细胞活力，采用了非放射性细胞增殖测定法。通过酶免疫测定法将剩余内皮的PGI2分泌定义为6-酮-前列腺素F1α代谢物。扫描电子显微镜观察显示，冷冻保存后，从HBD获取的移植物在收获后24小时内处理时显示内皮几乎融合，但从NHBD获取时则缺乏内皮细胞。从NHBD获取的冷冻保存移植物在光学显微镜和透射电子显微镜下检查时表现出组织结构改变，瓣叶海绵层内有水肿和空泡形成以及不可逆的细胞损伤。冷冻保存后HBD同种移植物的代谢活性得以维持，这通过已证实的PGI2分泌得到了证实（冷冻保存后为6150±1200 pg/3 ml M199），而NHBD的标本则分泌减少（1950±730 pg/3 ml M199），并且冷冻保存后几乎不分泌（P<0.0001）。（摘要截短至250字）
