组织工程小血管支架移植于异种动物的血流和管壁变化

Blood flow and vessel wall of heterogeneous animals transplanted with tissue engineered small vessel scaffolds

背景:脱细胞的异种小血管支架已被初步去除引起排斥反应的异种抗原。目的:将脱细胞的 Wistar 大鼠尾动脉支架移植于日本大耳白兔耳血管间,观察移植后血流和管壁变化。方法:15 只 Wistar 大鼠每只取 2 条长 2.50 cm 的尾动脉干共 30 条作为异种小血管,15 条直接作为供体尾动脉干,另 15条经 1%聚乙二醇辛基苯基醚脱细胞处理作供体组织工程小血管支架。受体为 15 只日本大耳白兔左右耳背面中央动脉。在外科显微镜下,兔中央动脉近侧断端采用全层套叠吻合法套入供体血管近侧腔内,远侧断端按常规端端吻合。采用勒通试验法和常规血管管腔血液、管壁染色法,连续观察血管内血流状况。结果与结论:血管移植后的即刻通畅率达 100%。异种小血管支架血液通畅最长时间为 46 h 47 min,长于异种小血管移植(14 h),两组远侧的端端吻合区首先出现血流不畅;套叠区小血管支架与中央动脉外膜间由蒂状结缔组织相连。第 10 天,小血管支架可见内膜纤维组织仍然呈梳头状整齐排列,未见细胞附着;在术后第 100 天,仍保留着血管支架的完整性。结果提示,脱细胞异种小血管支架可作为血管移植物吻合于动物宿主内,异种小血管支架移植的套叠式吻合法优于经典的端端吻合法。

BACKGROUND：The heterogenic antigen has been tentatively removed from acellular heterogeneous small vessel scaffolds due to inducing transplant rejection.OBJECTIVE：To transplant acellular tissue of Wistar rat＇s caudal artery into blood vessel of Japanese white rabbit＇s ear,and to discuss the changes of blood flow and vessel wall after the transplantation.METHODS：Fifteen Wistar rats were collected as donors,two caudal truncus arteriosus（2.50 cm long each） were harvested from each donor,then thirty caudal truncus arteriosus served as heterogeneous small vessels and were randomly assigned into two groups,15 of which as the caudal artery group,while the remaining were treated with 1% Triton X-100 as the small vessel scaffold group for tissue engineering.Fifteen Japanese white rabbits were involved as receptors,we took central arteries from left and right ears of each receptor.Under surgery microscope,the proximal broken end of Japanese white rabbit＇s central artery was totally overlapped into the proximal lumen of donor＇s vessel,while the distal broken end was sewed up by general end-to-end anastomosis.Blood flow in vessel wall was continuously observed through the staining of vascular lumen and wall.RESULTS AND CONCLUSION：The immediate patency rate of the recombinant blood vessel was 100%.The maximum time of the blood flowing of heterogenous scaffold from vessel was 46 hours and 47 minutes,which was longer than that of small blood vessel transplantation（14 hours）.The poor blood flow primarily occurred in end-to-end anastomosis from the distal broken;in the overlapping,the pedicle graft structures were connected between the small vessel scaffold and the central artery tunica.On day 10,tunica intima fibers,arranged in cylindrical conformation,were seen in the small vessel scaffold,with no cell attachment.On day 100,heterogenous scaffold form vessel still kept its shape and structure.Acellular heterogenous small vessel scaffold as a vascular graft can anastomose in animal hosts,the overlapping anastomosis is superior to the end-to-end anastomosis method.