电刺激股薄肌成形术原位肛门重建的犬实验研究

Dynamic graciloplasty for canine in situ anal reconstruction

目的 评价电刺激股薄肌成形术原位肛门重建的犬实验模型临床应用前景。方法 采用杂种犬 17条 ,分对照组和实验组两组 ,第 1期单行股薄肌原位游离 ,实验组术后行电刺激连续 6周 ;2组第 2期均行腹会阴联合切除肛门 +股薄肌原位肛门括约肌重建 ,术后 2周测量基础新肛压、功能性新肛压和移位股薄肌肌肉耐疲劳性曲线 ,取肌肉样本进行显微结构观察。结果 实验组的I型纤维所占比例明显高于对照组 (P <0 0 0 1) ;两组间基础肛压、基础新肛压的差异无显著性意义 (P >0 0 5 ) ,而功能性新肛压的差异有显著性意义 (P <0 0 1) ;实验组的移位股薄肌肌肉耐疲劳性曲线更平缓 ,平台期更长。结论 经过长期电刺激后 ,股薄肌纤维构成发生适应性改变 ,抗疲劳性改善 ,可替代括约肌的功能。

Objective To evaluate dynamic graciloplasty (DGP) for canine in situ anal reconstruction. Methods Seventeen dogs were randomly divided into experimental group and control group. In control group, on the stage 1, the gracilis muscle were dissected in situ, manometry performed intraoperatively; In experimental group, the gracilis muscle were dissected in situ and stimulated chronically starting 7 days postoperatively. On stage 2, abdominoperineal resection of anus and graciloplasty for anal reconstruction were performed in two groups. After 2 weeks recovery, manometry and muscular fatigue-resistant curve (MFRC) were observed while myostimulator is switched off and on. The muscle of neosphincter was biopsied. Results After chronic low frequency electrical stimulation (CLFS), the percentage of type Ⅰ fibers in the stimulation group was higher than the control group (P<0.001). There was no difference in basal pressure and basal neosphincter pressure between the 2 groups (P>0.05), but functioning neosphincter pressure is different significantly (P<0.01), and the shape of MFRC in the stimulation group was smoother with a longer platform. Conclusion DGP is technically feasible, with CLFS, the gracilis muscle underwent adaptive mechanism to improve the fatigue resistance, making it more suitable for the alternative function of neosphincter.