Stoelben Erich, Harpering Holger, Haberstroh Joerg, di Filippo Antonio, Wellens Eckhard
Department of Thoracic Surgery, University Hospital Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
Eur J Cardiothorac Surg. 2003 Jan;23(1):15-20. doi: 10.1016/s1010-7940(02)00671-1.
The successful use of cryopreserved tracheal allografts in canine models suggests their use in humans. The grade of genetic difference, the mechanism of revascularisation and the method of cryopreservation are not clearly defined. The purpose of our study was to investigate the rejection of tracheal transplants in a standardised heterotopic rat model using different forms of cryopreservation.
Tracheae from Brown Norway rats were implanted into the omentum from Brown Norway rats or Lewis rats. We transplanted fresh isografts or allografts and pretreated isografts or allografts. Cryopreservation was performed in a medium containing 10% dimethyl sulphoxide at -80 degrees C for 28 days (I) or -196 degrees C for 84 days (II) or without medium at -80 degrees C for 28 days (III). The transplants were excised after 7 and 21 days, respectively.
Histological examinations revealed normal structure and function of isografts after 21 days. In the cryopreserved isograft, the epithelium had disappeared and the tracheal lumen was partially obstructed by a non-compact fibrous tissue. In the fresh allografts, the epithelium was replaced by aggressive fibrous tissue, infiltrating the membranous part of the trachea and occluding the tracheal lumen. The cartilage was vital without any sign of rejection. In the cryopreserved allografts, the tracheal lumen was obstructed by dense fibrous tissue with an inflammatory reaction. The cartilage of cryopreserved allografts (II) and (III) had lost the nuclei corresponding to non-vital tissue. Only in the cryopreserved allografts (I) did we find nodular regeneration at the edges of the cartilaginous bow.
The heterotopic transplantation model allows the study of the mechanisms leading to tracheal obstruction. Cryopreservation was found to have no clear advantage in reducing transplant immunogenicity. Cryopreservation leads to significant damage to the cartilage, the intensity of which is dependent on the mode of cryopreservation.
在犬类模型中成功使用冷冻保存的气管同种异体移植物提示了其在人类中的应用前景。然而，遗传差异程度、血管再生机制以及冷冻保存方法尚未明确界定。本研究的目的是使用不同形式的冷冻保存方法，在标准化的异位大鼠模型中研究气管移植的排斥反应。
将来自棕色挪威大鼠的气管植入棕色挪威大鼠或刘易斯大鼠的大网膜中。我们移植了新鲜的同基因移植物或同种异体移植物以及经过预处理的同基因移植物或同种异体移植物。冷冻保存分别在含有10%二甲基亚砜的培养基中于-80℃下进行28天（I组）或在-196℃下进行84天（II组），或者在无培养基的情况下于-80℃下进行28天（III组）。移植后分别在7天和21天后取出移植物。
组织学检查显示，同基因移植物在21天后结构和功能正常。在冷冻保存的同基因移植物中，上皮消失，气管腔被疏松的纤维组织部分阻塞。在新鲜同种异体移植物中，上皮被侵袭性纤维组织取代，侵入气管膜部并阻塞气管腔。软骨存活，无任何排斥迹象。在冷冻保存的同种异体移植物中，气管腔被致密的纤维组织阻塞并伴有炎症反应。冷冻保存的同种异体移植物（II组）和（III组）的软骨细胞核消失，对应于无活力组织。仅在冷冻保存的同种异体移植物（I组）中，我们在软骨弓边缘发现了结节状再生。
异位移植模型有助于研究导致气管阻塞的机制。冷冻保存并未显示出在降低移植免疫原性方面有明显优势。冷冻保存会导致软骨严重损伤，损伤程度取决于冷冻保存方式。
