Sliding and
Paraesophageal Hernia
An acquired hiatal hernia is defined by the proximal movement of a
portion of the stomach into the chest through the diaphragmatic hiatus. Within
that general definition there are two subsets: a sliding hernia and a
paraesophageal hernia. A sliding hiatal hernia occurs as a result of a direct
proximal movement of the stomach through the hiatus with the gastroesophageal
junction. It is thought to form as a result of laxity of the phrenoesophageal
ligament that normally closes the diaphragmatic space around the
gastroesophageal junction and anchors the junction in place. It is the most
common type of hiatal hernia and is most associated with gastroesophageal
reflux. The reason for this is multifactorial and includes (1) loss of the
crural diaphragm contribution to lower esophageal sphincter tone, (2) stasis of
refluxed content within the hernial sac, and (3) disruption of the acute angle
of His, which has a valvelike function in preventing reflux. With larger
crural defects and, hence, diameters of the hernia, these defects are more
pronounced and the degree of reflux is greater. As a result, larger hiatal
hernias tend to be more associated with complications of gastroesophageal
reflux, such as erosive esophagitis, esophageal strictures, and Barrett
esophagus. It is also more difficult to control the reflux through lifestyle
and pharmacologic interventions; surgical correction such as fundoplication is
needed in some patients.
In contrast, in a paraesophageal
hernia, the gastroesophageal junction remains fixed in place without proximal
migration of the proximal portion of the stomach. Although the herniation is
through the phrenoesophageal membrane and hiatal opening, the junction stays in
place through its attachment to the periaortic fascia and median arcuate
ligament. The herniation may begin with the gastric fundus but in time
progresses to include a large portion of the stomach, if not the entire
stomach. When a large portion is involved, the stomach may flip up through the
hiatus by two configurations. The first is in a mesenteroaxial direction, that
is, on a dividing line between the proximal and distal stomach. When the entire
stomach herniates through the diaphragm into an upsidedown position at both
the proximal and distal margins of the stomach, this is termed an organoaxial
hernia. A paraesophageal hernia is not deleterious necessarily because of
gastroesophageal reflux but because of the threat of incarceration and
strangulation of the stomach in the diaphragmatic hiatus due to vascular
compromise of the angulated gastric vasculature. Patients may
present at first with symptoms of postprandial chest or epigastric pain from
partial obstruction and early satiety due to reduction of the size of the
gastric pouch. Presentation with incarceration can be catastrophic excruciating
chest pain and shock associated with frank gastric infarction and death if not
addressed immediately. Surgical correction securing the stomach below the
diaphragm and closing of the hiatus is needed for symptomatic patients or a
young patient with a large hernia.
With large diaphragmatic defects,
organs adjacent to the stomach such as the colon and spleen may also herniate
into the chest. Finally, although these types of hiatal hernias are strictly
defined, a combination of both a sliding and a paraesophageal hernia is common.
These patients may present with both reflux symptoms and symptoms of pouch
obstruction. As a result, surgical correction for these patients (if not for
most patients with a large hernia of any type) requires both reduction of
the hernia and fundoplication.
