大鼠异体皮瓣移植后不用免疫抑制剂情况下移植物坏死的主要原因

目的 探讨大鼠异体皮瓣移植后不用免疫抑制剂情况下移植物坏死的主要原因.方法 实验分为3组,每组受者均为8只,以股动、静脉为蒂进行下腹部皮瓣移植.A组:以BrownNorway(BN)大鼠为供者,Lewis(LEW)大鼠为受者,移植术后2周内使用免疫抑制剂西罗莫司4mg·kg-1·d-1腹腔注射;B组:以BN大鼠为供者,LEW大鼠为受者,移植后不使用任何药物;C组:为LEW大鼠自体移植对照组,术后不使用任何药物.术后观察各组移植物的大体变化,并取移植物进行病理学检查,比较各组的病理学变化.结果 A组自术后17 d起,陆续出现皮瓣红斑,表皮脱落,真皮及皮下组织则最后坏死;B组受者排斥反应进展迅速,表皮不出现脱落现象,皮瓣直接完全发黑、坏死.C组移植物长期存活,未见排斥反应征象.A、B两组从出现排斥反应迹象到组织完全坏死的时间分别为(16.7±3.0)d和(5.4±1.1)d.病理检查显示:A组表皮组织首先被排斥,真皮和皮下组织由于大量淋巴细胞浸润而坏死.B组则为移植皮瓣真皮下血管网内皮细胞坏死,血管栓塞,皮肤内细胞缺血而坏死.结论 微血管栓塞是大鼠异体皮瓣移植后不应用免疫抑制剂情况下移植物坏死的主要原因.

Capillary embolism is the main cause of grafts necrosis in a vascularized skin flap allotransplantation model in rats

Objective To understand acute rejection differences between untreated recipients and rapmycin-treated recipients in a rat free flap allotransplantation model. Methods Brown groin free flaps were transplanted to Lewis recipients. In the treated group, recipients were treated with rapamycin at the dose of 4 mg/kg every day from day 0 to day 14 after transplantation. In the untreated group, recipients didn't receive any treatment. Allografts were evaluated clinically and histologically. Results Allografts in the treated group showed epidermolysis as sign of rejection.Rejection sign of untreated grafts was ischemic necrosis of whole skin. In histological evaluation, the treated grafts showed "band-like" lymphocytes infiltration in the upper dermis when rejection occurred, while the untreated grafts showed thrombosis in the subdermal vessels. Conclusion The differences between the two groups implied that embolization may be responsible for the rejection of free flap allotransplantation in rat model.