贲门失弛缓症下段食管壁顺应性和残余应力分布

Compliance and residual stress distribution of lower esophagus in achalasia

目的 :研究贲门失弛缓症下段食管的应力 -生长关系。 方法 :将 2 0只猫随机分为对照组和贲门失弛缓症病变模型组 ,病变组于胃镜下在下食管括约肌 (L ES)处分 4点环行注射苄基二甲基十四烷氯化铵 (BAC) 0 .5 ml/点 ,对照组注射等量生理盐水。病变组于 4、6、8周后 ,对照组于 8周后 ,测 L ES压力 (L ESP)和食管体部收缩波幅。取食管下 1 / 3段测不同拉伸比下的压力 -容积 ,并以指数曲线拟合。将实验段食管垂直轴向剪成长度约 2 mm的环状 ,扫描读取管壁厚度、内外周径 ,再径向剪开食管环 ,扫描张开角 ,计算其残余应力。 结果 :病变组在注射 BAC后 4、6、8周 ,L ESP分别为 (31 .2± 5 .1 1 )、(30 .6± 3.6 1 )、(32 .2± 3.76 ) mm Hg(1 m m Hg=0 .1 33k Pa) ,较注射前显著增高 (P<0 .0 5、P<0 .0 1和 P<0 .0 1 ) ,而对照组较注射前无显著差异 (P>0 .0 5 ) ;两组动物食管体部收缩波幅均较注射前无显著变化。病变组 4、6周后下段食管的顺应性均较对照组显著降低 (P<0 .0 5 ) ,以注射后 4周最小。病变组下段食管内壁的残余应力较对照组均显著减小 (P<0 .0 5 ) ,但随病程的延长而逐渐接近对照组。 结论 :贲门失弛缓症食管下段的顺应性降低 。

Objective:To study the stress growth relation of lower esophagus in achalasia. Methods: Gastroscope benzyldimethyltetradecylammonium chloride (BAC) or saline were injected circumferentially into the lower esophagus sphincter(LES) of 20 healthy cats, which were divided into 4 groups (4, 6, 8 weeks group and control group, n =5). Manometries were performed before and after injection. The pressure volume(P V) data of lower 1/3 parts of esophagus at various axial extension ratios and the variations of zero compliance and compliance with pressure in each group were measured. Finally the tested esophaguses were cut into rings with about 2 mm in length. After the wall thickness, inner radius and extra radius were scanned, the rings were opened to scan the opening angles for demonstration of the zero stress state, then the residual stress distribution of the lower esophagus were calculated. Results: LESP in BAC injection group were significantly higher than those of the control group 4,6 and 8 weeks later [(31.2±5.11),(30.6±3.61) and (32.2±3.76) mmHg vs (17.0± 3.10), (17.8±2.79) and (17.8±1.33) mmHg, P <0.05, P <0.01 and P <0.01]. The lower esophagus of BAC treated cats showed lower compliance and residual stress compared to those of the control. But the difference was decreased followed by the progress of the disease. Conclusion: It is suggested that the compliance of the lower esophagus in achalasia is decreased and the abnormalities of mechanics property are significant.