Anatomical investigation of the esophageal and aortic hiatuses: physiologic, clinical and surgical considerations.

Precise knowledge about the anatomical constitution of the diaphragmatic pillars is essential to understand the physiologic, clinical and surgical roles of the esophageal and aortic hiatuses. Because anatomical descriptions found in the literature are dubious, we have decided to investigate this subject. Anatomical dissections and histologic sections of the right and left diaphragmatic pillars (diaphragma crura) from 43 human bodies were analyzed, comprising both non-fixed and fixed specimens. We have described a classification of the diaphragmatic pillars and their muscular branches, forming two basic arrangements (patterns I and II) around the esophageal and aortic hiatuses. Such anatomical and functional relationships between the esophagus and its diaphragmatic hiatus help explain why, during normal inspiration, a hiatal enlargement is observed first but is followed, thereafter, during deep inspiration, by a hiatal narrowing exerted by the contraction of the diaphragmatic pillars. Our results also show that the aortic hiatus does not seem to constitute a rigid ventral tendinous arc around the aorta that could impose any considerable degree of vascular compression, as suggested by other investigators. The present study provides anatomical data useful for a better understanding of gastroesophageal reflux physiology, antireflux surgery and abdominal angina.