Development of a new method of tracheal transplantation for clinical application

在本研究中，我们探讨了在含有海藻糖的保存液(TC液)中延长犬气管冷冻时间的可能性，探讨了长期冷冻后无免疫抑制的犬同种异体气管移植的可能性，确定了气管移植物的最大可能长度，并尝试了一种新的手术方法，以实现移植气管的可靠血运重建。结果表明，气管在TC液中冷冻保存1个月是可能的，无免疫抑制剂的同种异体气管移植在TC液中保存9个月后仍然是可能的，即使有大网膜固定术也不可能使用辐照的同种异体气管进行10环同种异体气管移植，这种新的方法称为“裂解气管移植”，是一种简单而可靠的延长气管切除的方法。随后，我们探讨了无免疫抑制剂的犬同种异体十环气管移植在TC液冷冻保存9个月后与裂开气管移植相结合的可行性。然而，这些动物死于气管狭窄，可能是由于移植物的存活能力受损。综上所述，我们将在不久的将来使临床同种异体气管移植成为可能，届时通过冷冻保存方法降低同种异体气管移植物的同种异体活性和维持移植物的存活都是可行的。

In this study, we investigated the possibility of prolonged cryoprescrvation of canine tracheas in a preservation solution containing trehalose (TC solution), examined the possibility of immnosuppressant-free canine tracheal allotransplantation after long-term cryopreservation, determined the maximum possible length of tracheal grafts, and tried a new operative proccdure to accomplish reliable revascularization of transplanted tracheal grafts. We demonstrated that consistent cryopreservation of the trachea for 1 month is possible in TC solution, immunosuppressant-free canine tracheal allotransplantation is consistently possible after 9 months of cryopreservation of the graft in TC solution, the impossibility of performing ten-ring tracheal allotransplantation using irradiated grafts even with omentopexy, and that the new proccdure called "split tracheal transplantation" is an easy and reliable way to extend tracheal resection. Thereafter, we examined the feasibility of the combination of immunosuppressant-free canine ten-ring tracheal allotransplantation after 9 months of cryopreservation with TC solution and the split tracheal transplantation. However, the animals died from tracheal stenosis presumably due to impaired viability of the grafts. In conclusion, we will make clinical tracheal allotransplantation possible in the near future, when both of reduction of allogenicity and maintenance of viability of tracheal grafts become fesible by means of cryopreservation.