Rare Diaphragmatic Hernias in Adults-Experience of a Tertiary Center in Esophageal Surgery and Narrative Review of the Literature.

A rare entity of non-hiatal type transdiaphragmatic hernias, which must be clearly differentiated from paraoesophageal hernias, are the phrenic defects that bear the generic name of congenital hernias-Bochdalek hernia and Larey-Morgagni hernia, respectively. The etiological substrate is relatively simple: the presence of preformed anatomical openings, which either do or do not enable transit from the thoracic region to the abdominal region or, most often, vice versa, from the abdomen to the thorax, of various visceral elements (spleen, liver, stomach, colon, pancreas, etc.). Apart from the congenital origin, a somewhat rarer group is described, representing about 1-7% of the total: an acquired variant of the traumatic type, frequently through a contusive type mechanism, which produces diaphragmatic strains/ruptures. Apparently, the symptomatology is heterogeneous, being dependent on the location of the hernia, the dimensions of the defect, which abdominal viscera is involved through the hernial opening, its degree of migration, and whether there are volvulation/ischemia/obstruction phenomena. Often, its clinical appearance is modest, mainly incidental discoveries, the majority being digestive manifestations. Severe digestive complications such as strangulation, volvus, and perforation are rare and are accompanied by severe shock, suddenly appearing after several non-specific digestive prodromes. Diagnosis combines imaging evaluations (plain radiology, contrast, CT) with endoscopic ones. Surgical treatment is recommended regardless of the side on which the diaphragmatic defect is located or the secondary symptoms due to potential complications. The approach options are thoracic, abdominal or combined thoracoabdominal approach, and classic or minimally invasive. Most often, selection of the type of approach should be made taking into account two elements: the size of the defect, assessed by CT, and the presence of major complications. Any hiatal defect that is larger than 5 cm (the hiatal hernia surface (HSA)) has a formal recommendation of mesh reinforcement. The recurrence rate is not negligible, and statistical data show that the period of the first postoperative year is prime for recurrence, being directly proportional to the size of the defect. As a result, in patients who were required to use mesh, the recurrence rate is somewhere between 27 and 41% (!), while for cases with primary suture, i.e., with a modest diaphragmatic defect, this is approx. 4%.