Pettersson G B, Bombeck C T, Nyhus L M
Ann Surg. 1981 Feb;193(2):214-20. doi: 10.1097/00000658-198102000-00016.
Sliding hiatal hernia has long term been implicated as a cause of lower esophageal sphincter (LES) incompetence and gastroesophageal reflux. The physics of LES function in hiatal hernia were investigated in in vitro and in vivo experiments. In vitro models of sliding hernias were constructed from excised canine gastroesophageal specimens. A "sphincter" was simulated with a rubber band around the gastroesophageal junction. It was found that placement of a ligature "hernia ring" on the stomach increased the opening pressure of the model sphincter. Addition of a tissue "hernia sac" sutured to the esophagus above the sphincter further increased the opening pressure, the protective effect being related to the pressure transmitted from the stomach to the hernia sac. There was no fluid leakage from the hernia sac between the hernia ring and the stomach. In anesthetized dogs (in vivo model) gastric and esophageal pressures were measured during gastric infusion while the LES gas way to reflux. A ligature tied loosely around the stomach to simulate a "hernia ring" and a sliding hernia without a hernia sac increased both the opening and the closing pressures of the LES by 36 +/- 18% and 35 +/- 20% (mean +/- SD), respectively. The opening pressure was increased by a decrease in gastric wall tension at the gastroesophageal junction, which was caused by the decreased radius of the herniated portion of the stomach. Pressure transmitted from the stomach to the hernia sac added to the LES pressure, and thereby further increased the opening pressure of the sphincter. The results explain how gastroesophageal reflux may be prevented in patients with hiatal hernia. It was recognized that the hernia sac may protect the sphincter, provided that it inserts into the esophagus above the LES.
滑动性食管裂孔疝长期以来一直被认为是食管下括约肌（LES）功能不全和胃食管反流的一个原因。通过体外和体内实验研究了食管裂孔疝中LES功能的物理学机制。滑动疝的体外模型由切除的犬胃食管标本构建而成。在胃食管交界处用橡皮筋模拟一个“括约肌”。研究发现，在胃上放置一个结扎“疝环”会增加模型括约肌的开放压力。在括约肌上方的食管上缝合一个组织“疝囊”会进一步增加开放压力，这种保护作用与从胃传递到疝囊的压力有关。在疝环和胃之间的疝囊没有液体泄漏。在麻醉犬（体内模型）中，在胃内灌注期间测量胃和食管压力，同时观察LES防止反流的作用。在胃周围松散地系一个结扎以模拟一个“疝环”，一个没有疝囊的滑动疝分别使LES的开放压力和关闭压力增加了36±18%和35±20%（平均值±标准差）。开放压力的增加是由于胃食管交界处胃壁张力的降低，这是由胃疝出部分半径的减小引起的。从胃传递到疝囊的压力加到LES压力上，从而进一步增加了括约肌的开放压力。这些结果解释了食管裂孔疝患者如何预防胃食管反流。人们认识到，只要疝囊插入LES上方的食管，它就可能保护括约肌。
