真皮替代物移植后的血管化过程及组织学变化的实验研究

目的了解不同种类真皮替代物移植后的血管化过程及组织学变化。方法将21只SD大鼠根据其皮下埋植不同的真皮替代物分为猪脱细胞真皮基质(sADM)组、人脱细胞真皮基质(hADM)组及人工真皮(Integra)组。于埋植后2、3、4、7、10、14、21、30、60、90、120、150、180d行移植物大体观察,采用免疫组织化学法观察移植物的血管化过程及组织学变化。结果大体观察术后各组大鼠创口周围皮肤无明显红肿及炎性反应,切口愈合良好,移植物与创面接触紧密。90d后各组移植物不易从体表触及。180d时,部分移植物面积缩小、厚度变薄甚至难以辨认。组织学观察移植术后2d起可见成纤维细胞、中性粒细胞、淋巴细胞等侵入移植物内,3d时与受床组织连接处可见长入的新生毛细血管芽。30—60d,移植物内形成丰富的血管网。150d后近似正常真皮结构。180d后部分移植物有不同程度吸收退化。结论3种真皮替代物移植后均能很快建立与受床组织的血液循环,并长时间存留于创面,但有一定程度的吸收退化。

The histological changes and the revascularization process in the grafted dermal substitutes

Objective To observe the revascularization process and histological changes in the dermal substitutes after grafting. Methods Twenty-one SD rats were enrolled in the study and were randomly divided into swine acellular dermal matrix ( sADM ), human acellular dermal matrix ( hADM ),and artificial dermal equivalent (Integra) groups according to different dermal substitutes grafted underneath the skin of SD rats. The gross appearance of the grafts was observed, and the tissue biopsies were harvested at 2, 3, 4, 7, 10, 14, 21, 30, 60, 90, 120, 150, 180 post grafting day (PGD) for the observation of the revascularization process and their histological changes. Results Gross observation: The incision in each group healed well without local swelling and inflammatory response after grafting. The grafts had a compact contact with the wounds.The texture of the grafted dermis in each group was soft and could not be felt from the surface of the body on 90 PGD.The presence of the grafts could be discerned on 180 PGD in all the groups,but some of them became smaller in size and thinner, even hard to identify in a few.Fibroblasts, neutrophiles and lymphocytes migrated into the grafts from 2PGD on. New capillary sprouts from the receiving beds could be observed after 3PGD.Affluent capillary nets formed in the grafts during 30 to 60 PGD. The structure of the grafts became nearly unidentifiable from the native dermis after 150 PGDs.Absorption and degradation to various degrees occurred in some of the grafts after 180 PGD. Conclusion The revascularization of the three dermal substitutes could begin shortly after grafting.The sponge-like structure of the substitutes was advantageous for the migration of the host fibroblast into the substitute and for the secretion of the new extra-cellular matrix.The dermal substitutes could last in the wound for a long time with partial absorption and degeneration.