细菌纤维素补片修复重建兔颈段气管部分缺损的实验研究

EXPERIMENTAL STUDY ON RECONSTRUCTION OF PARTIAL DEFECTS OF CERVICAL TRACHEA WITH BACTERIAL CELLULOSE PATCH IN RABBITS

目的探讨细菌纤维素补片修复重建兔气管缺损的可行性,为研制细菌纤维素人工气管奠定基础。方法取成年大耳白兔30只,体质量2.5-3.5 kg,制备大小为1.0 cm×0.6 cm（2-3个气管环）的颈段气管前壁、侧壁全层缺损模型。依据修复材料不同,将其随机分为实验组及对照组（n=15）,分别以直径约为1.2 cm的细菌纤维素补片（6层重叠）以及自体颈部浅筋膜修复重建。术后观察动物一般情况,于4、8、12周取材行大体观察并测量气管狭窄程度,组织学观察并计数新生毛细血管,扫描电镜观察重建管腔处情况。结果术后实验组及对照组各3只动物死于感染、气管狭窄或气道分泌物潴留所致窒息,其余动物均存活至实验完成。大体观察示,两组移植补片逐渐与周围组织粘连,并被结缔组织包裹,见类似滋养血管的小血管;各时间点实验组气管狭窄程度与对照组比较,差异无统计学意义（P〉0.05）。组织学观察示,随时间延长实验组移植补片及吻合口附近可见连续黏膜上皮细胞生长,且细胞形态逐渐成熟;而对照组黏膜上皮细胞排列松散。各时间点实验组新生毛细血管数均多于对照组（P〈0.05）。扫描电镜观察示,实验组随时间延长,吻合口处出现连续上皮细胞,并向补片中段爬行;而对照组上皮细胞较实验组少,且不连续。结论细菌纤维素补片修复重建兔气管缺损可行,新黏膜形成早且完整,有望作为人造气管材料。

Objective To investigate the feasibility of bacterial cellulose patch to repair and reconstruct rabbit tracheal defect, so as to lay the foundation for the development of bacterial cellulose artificial trachea. Methods Thirty adult rabbits（weighing, 2.5-3.5 kg） were selected to establish full-thickness defect of the cervical trachea（1.0 cm×0.6 cm in size） which involved the anterior and side walls and 2-3 rings. Defect was repaired with sheet bacterial cellulose（1.2 cm in diameter and 6 layers） in experimental group（n=15）, and with autologous cervical fascia in control group（n=15）. The general condition of the animals was observed after operation; after 4, 8, and 12 weeks, the samples were obtained for measuring the tracheal stenosis degree, counting new microvessels, and observing lumen reconstruction situation by scanning electron microscope. Results Three rabbits died of infection, tracheal stenosis, or asphyxia caused by airway secretions retention in 2 groups respectively, and the other rabbits survived to the end of experiment. Gross observation showed that reconstruction materials gradually adhered to adjacent tissue and were enwrapped by connective tissue, small blood vessels like nutrient vessel were seen in 2 groups; no significant difference was found in the tracheal lumen stenosis degree between 2 groups（P〉0.05）. Histological observation showed that the continuous growth of mucosal epithelial cells was observed near patch and anastomosis site with time, and cell morphology gradually turned mature in experimental group; while mucosal epithelial cells arranged loosely in control group. At each time point, new capillaries of experimental group were significantly more than those of control group（P〈0.05）. Scanning electron microscope observation showed the continuous epithelioid cells were observed at anastomosis site with time, and gradually grew into the middle of the patch in experimental group; while less and discontinuous epithelioid cells were observed in control group. Conclusion Bacterial cellulose patch is feasible to reconstruct cervical tracheal defect in rabbits, and the new mucosa is formed early and completely, so it is expected to be used as artificial trachea material.