新生兔同种主动脉带瓣管道移植的形态学研究

Morphological study on implanted valved aortic homograft conduit of neonate rabbit

目的 :观察新生动物的同种主动脉带瓣管道 (VAHC)移植后的形态学变化。方法 :以体重 15 0～ 2 0 0 g的新西兰兔 2 4只作为 VAHC的供体 ,0 .9～ 1.2 kg的幼兔和 2 .1～ 2 .9kg的成年兔各 12只为受体 ,建立新生兔的 VAHC移植模型。术后 1个月和 6个月分别取材作大体形态测量及组织学观察。结果 :发现植入的 VAHC内膜光滑 ,无血栓 ;与植入时相比 ,各组 VAHC血管壁厚度及植入幼兔体内 6个月 VAHC长度和管径明显增加 (P<0 .0 5 ) ;与未植入的新生兔 VAHC相比 ,植入幼兔体内 6个月的 VAHC瓣叶高度、游离缘长度均增加 (P<0 .0 5 )。组织学检查显示 VAHC血管壁存在三层结构 ,内膜及中层轻度增厚 ,管壁有少量单核细胞及淋巴细胞浸润 ,植入成年兔体内 6个月的变化最为明显。结论 :新生兔的 VAHC植入幼兔体内后其血管的直径和长度、瓣叶的高度和游离缘长度可随幼兔的发育而增加 ,提示在临床上应用小的 VAHC是可行的。

AIM: To observe the post implantation morphological changes in valved aortic homograft conduit(VAHC) of neonate rabbit. METHODS: The animal model of the VAHC was established via retroperitoneal pathway. Neonatal New Zealand rabbits(weight:150~200 g, n =24) were used as donors of the VAHCs, and young (0.9~1.2 kg, n =12) and adult rabbits (2.1~2 9 kg, n =12) as recipients. The specimens harvested 1 month and 6 months after the implantation were measured and studied under microscope. RESULTS: The intima of VAHCs was smooth and no emboli were found. The thicknesses of the walls in all the VAHCs, the lengths and diameters of the VAHCs in the young recipients 6 months post implantation increased significantly than those before the operation( P <0.05). The heights and free edge lengths of cusps in the VAHCs implanted in the 6 months were higher than those of the control VAHCs ( P <0.05). Light microscopic examination of the explanted VAHCs revealed intimal and media proliferation, cellular infiltration and valvular thickening. The above changes were even more obvious in the adult recipients 6 months post implantation. CONCLUSION: The VAHCs of neonate rabbits implanted in the young rabbits can increase with the growth of recipients,which indicates that small VAHC may be applied clinically.