新生动物同种主动脉带瓣管道移植的组织形态学观察

Histological and morphological study on implanted valved aortic homograft conduit of neonate rabbit

目的 :观察新生动物同种主动脉带瓣管道 (VAHC)移植后的组织形态学变化。方法 :新生兔为供体 ,其VAHC抗生素灭菌后经腹膜外植入幼兔及成年兔的腹主动脉 ,术后 1个月和 6个月取材作组织形态学观察。结果 :移植的VAHC搏动良好 ,内膜光滑 ,无血栓。瓣膜无皱缩 ,交界无粘连。光镜下血管壁内膜和中层有不同程度的增厚 ,可见炎性细胞浸润。电镜下的超微结构均有所改变 ,以植入成年兔体内 6个月的VAHC最为明显 ,主要表现为血管壁平滑肌细胞增生 ,胞内细胞器少 ,内质网明显扩张 ,甚至呈空泡样改变 ,可见淋巴细胞和单核细胞浸润及钙化斑。瓣膜胶原纤维排列散乱 ,部分成纤维细胞内质网扩张 ,胞浆内有脂褐素沉积。结论 :本实验表明 ,新生动物的VAHC移植后的组织形态呈较明显的慢性排异反应征象。

Objective:To observe the histological and morphological changes of implanted valved aortic homograft conduits(VAHC) of neonate rabbits.Method:Neonatal New Zealand rabbits were used as donors of the VAHC and young and adult rabbits as recipients.The VAHCs implanted to the infrarenal abdominal aortae of recipients by the retroperitoneal approach after sterilization by antibiotics were retrieved in 1 and 6 months after the operation.Result:The macroscopy showed an optimal pulsation and smooth intima in the aortic wall,no leaflet retraction and commissural fusion in the valve.Light microscopic examination of explanted VAHCs revealed intimal and media proliferation,cellular infiltration and valvular thickening.Obvious changes were observed by transmitting electron microscopy,especially in the sections extracted in 6 months after the inplantation.Ultrastructural investigatons revealed the hyperlasia,a decrease of organelle,dilated endoplasmic reticula and even vacuole of smooth muscle cell,monocyte and lymphocyte infiltration in the aortic wall,divergent collagenous fibers,dilated endoplasmic reticula of fibroblast in the valve.Conclusion:The histological changes of implanted VAHCs manifest obvious chronic immunological rejection and indicate it may be necessary to match donor\|recipient histocompatility and use immunosuppression at the time of small VAHC implantation. [