Objective: To study the feasibility and advantages of preparing an animal model of defecation reconstruction after spinal cord injury in rats by mechanical polishing method.
Methods: Forty adult female Sprague Dawley rats (weighing, 250-300 g) were randomly divided into 2 groups (n=20). The lamina was opened by mechanical polishing method to expose the cauda equina in experimental group, then bilateral L5 and S1 nerve roots end-to-end anastomosis was done under 10 times microscope, and finally cauda equina between the L5 and L6 (except S1) was cut. The lamina was opened by traditional bites method in control group, and the other treatment methods were in agreement with the experimental group. The operative time, intra-operative blood loss, and situation of rats at postoperative 3 days were recorded.
Results: The operative time of experimental group[(93.05±7.60) minutes] was significantly shorter than that in control group[(131.30±11.68) minutes] (t=12.279, P=0.000); intra-operative blood loss in experimental group[(4.33±0.46) mL] was significantly lower than that in control group[(7.36±0.58) mL] (t=18.293, P=0.000). At 3 days after operation, 18 rats (90%) survived in experimental group, and 12 rats (60%) survived in control group; difference was significant in the survival rate between 2 groups (χ2=4.800, P=0.028).
Conclusions: To establish an animal model of defecation reconstruction after spinal cord injury in rats by mechanical polishing method is feasible, and it has shorter operative time, less blood loss, and lower postoperative mortality than the traditional bites method. But there is a certain learning curve and requirement to master microsurgical techniques.
目的: 通过与传统钳咬法比较，探讨器械打磨法制备大鼠脊髓损伤后排便功能模型的可行性及优势。.
方法: 取成年雌性SD大鼠40只，体质量250~300 g，随机分为2组，每组20只。实验组采用器械打磨法打开椎板，暴露马尾神经，10倍显微镜下将双侧L5与S1前后神经根分别作端端吻合，最后在L5与L6之间离断马尾神经（S1除外）。对照组采用传统钳咬法打开椎板，其余处理方法与实验组一致。记录并比较两组手术时间、术中出血量以及术后3 d大鼠情况。.
结果: 实验组手术时间为（93.05±7.60）min，较对照组（131.30±11.68）min明显缩短；术中出血量为（4.33±0.46）mL，明显低于对照组的（7.36±0.58）mL；以上两指标比较差异均有统计学意义（t=12.279，P=0.000；t=18.293，P=0.000）。术后3 d，实验组18只大鼠存活，存活率为90%；对照组12只大鼠存活，存活率为60%；两组术后3 d大鼠存活率比较，差异有统计学意义（χ2=4.800，P=0.028）。.
结论: 器械打磨法制备大鼠脊髓损伤后重建排便功能模型可行，与传统钳咬法比较具有手术时间短、术中出血少及术后大鼠死亡率低等优点；但该方法有一定学习曲线且对术者显微外科技术要求较高。.
Keywords: Animal model; Bites method; Defecation reconstruction; Mechanical polishing method; Rat; Spinal cord injury.