Potential fascial dome made by the upper leaf of the phreno-esophageal membrane

Mesoesophagus and other fascial structures of the abdominal and lower thoracic esophagus: a histological study using human embryos and fetuses

A term "mesoesophagus" has been often used by surgeons, but the morphology was not described well. To better understand the structures attaching the human abdominal and lower thoracic esophagus to the body wall, we examined serial or semiserial sections from 10 embryos and 9 fetuses. The esophagus was initially embedded in a large posterior mesenchymal tissue, which included the vertebral column and aorta. Below the tracheal bifurcation at the fifth week, the esophagus formed a mesentery-like structure, which we call the "mesoesophagus," that was sculpted by the enlarging lungs and pleural cavity. The pneumatoenteric recess of the pleuroperitoneal canal was observed in the lowest part of the mesoesophagus. At the seventh week, the mesoesophagus was divided into the upper long and lower short parts by the diaphragm. Near the esophageal hiatus, the pleural cavity provided 1 or 2 recesses in the upper side, while the fetal adrenal gland in the left side was attached to the lower side of the mesoesophagus. At the 10th and 18th week, the mesoesophagus remained along the lower thoracic esophagus, but the abdominal esophagus attached to the diaphragm instead of to the left adrenal. The mesoesophagus did not contain any blood vessels from the aorta and to the azygos vein. The posterior attachment of the abdominal esophagus seemed to develop to the major part of the phrenoesophageal membrane with modification from the increased mass of the left fetal adrenal. After postnatal degeneration of the fetal adrenal, the abdominal esophagus might again obtain a mesentery. Consequently, the mesoesophagus seemed to correspond to a small area containing the pulmonary ligament and aorta in adults.

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.

Does the cardinal ligament of the uterus contain a nerve that should be preserved in radical hysterectomy?

The cardinal ligament (CL) of the uterus is present as a specific part of the parametrium when the pararectal and paravesical spaces are developed surgically. According to usual nerve-sparing radical hysterectomy (the Tokyo method), the CL is divided into two parts, the vascular part for dissection and the nerve part that contains the pelvic splanchnic nerve (PSN) as a major target for nerve sparing. In contrast, we hypothesized that the CL and another structure outside of the usual area for surgical dissection, that is, the lateral rectal ligament, are mutually continuous and that the PSN runs through the lateral ligament rather than the CL. In the present study, a combination of routine dissection, fresh cadaver dissection and in situ sectional anatomy revealed that: (i) the CL did not contain the PSN; (ii) a well-defined fascial structure existed in the bottom or dorsal margin of the CL area; and (iii) the pelvic plexus was separated from vascular components of the CL. The present results provide a new perspective for nerve-sparing radical hysterectomy with extensive lateral parametrial dissection of the CL.