去抗原牛松质骨中利用动静脉袢诱导轴向血管化的实验研究

INDUCTION OF AXIAL VASCULARIZATION IN PROCESSED BOVINE CANCELLOUS BONE SCAFFOLD USING ARTERIOVENOUS LOOP

目的探讨在去抗原牛松质骨中利用动静脉袢诱导轴向血管化的方法及血管化效果。方法取新鲜牛股骨采用常规方法制备去抗原牛松质骨支架,并将其加工成带环状侧槽的圆柱形。健康3～4月龄雄性SD大鼠30只,体重300～350g,随机分为实验组和对照组(n=15)。实验组于大鼠右侧股部行股静脉分离,并将其移植至对侧股动静脉残端间构建动静脉袢,将制备的去抗原牛松质骨支架插入至动静脉袢中,并将动静脉袢置于其环状凹槽内;对照组仅将股部血管结扎切断,无需吻合,同时植入去抗原牛松质骨支架。术后2、4、8周取材行大体观察、墨汁灌注组织学观察并检测微血管体积密度。结果术后各时间点实验组标本颜色鲜红,勒血实验显示血管双向通畅;对照组标本颜色暗红,触之略感柔韧。墨汁灌注组织学观察显示,实验组去抗原牛松质骨支架有明显血管化,以第8周显著,血管趋于成熟并呈网状,可见起源于动静脉袢的新生血管芽。对照组无血管化发生。术后2、4、8周实验组微血管体积密度分别为(3.59±1.84)、(16.61±10.23)、(39.04±13.46)μm3/μm3,对照组分别为(2.43±0.97)、(6.79±2.92)、(25.31±10.98)μm3/μm3。术后4、8周比较差异均有统计学意义(P<0.05),术后2周差异无统计学意义(P>0.05)。结论动静脉袢诱导去抗原牛松质骨血管化模型作为一种新的预血管化策略,可能为制备功能性人工骨提供参考。

Objective To explore the method of inducing axial vascularization in a processed bovine cancellous bone scaffold by using an arteriovenous loop, and to evaluate its effect ofvascularization. Methods Custom-made processed bovine cancellous bone discs were processed into cylinder with circular grooves. Thirty male SD rats weighing 300-350g （3-4 months old） were randomly divided into 2 groups （n=15 per group）： experimental group in which the femoral veins in the groin of rats were separated and transplanted to the contralateral femoral artery and vein stump, the processed bovine cancellous bone scaffold was inserted into the arteriovenous loop, which was placed into the annular groove. Control group, in which the blood vessels in the groin of rats were cut, no anastomosis was conducted, and the processed bovine cancellous bone scaffold was planted. At 2, 4 and 8 weeks after operation, gross observation, ink infusion histology observation and microvessel bulk density detection were conducted. Results At each postoperative time point, the samples in the experimental group were fresh red, the circulation of blood vessels were smooth bidirectionally, while the samples in the control group were dark red soft, and flexible. Ink infusion histology observation showed the processed bovine cancellous bone scaffold in the experimental group had obvious vascularization, the blood vessels tended to be mature and integrated into network, and neovascular sprouts originated from arteriovenous loop were evident, especially at 8 weeks after operation; while there was no vascularization in the control group. At 2, 4 and 8 weeks after operation, the bulk density of the microvessels in the experimental group was （3.59±1.84）, （16.61±10.23） and （39.04±13.46）μm^3/μm^3, respectively, and it was （2.43±0.97）, （6.79±2.92） and （25.31±10.98）μm^3/μm^3, respectively, in the control group. Significant differences was noted between two groups at 4 and 8 weeks after operation （P 〈0.05）, and no significant difference was evident at 2 weeks after operation （P 〉0.05）. Conclusion Inducing vascularization in a processed bovine cancellous bone using an arteriovenous loop is a new strategy of prevascularization and may provide valuable clues for the preparation of functional artificial bone.