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The diaphragm is a flat sheet of muscle tissue that separates
your chest from your abdomen. Normally, all of your stomach organ
is below the diaphragm. To reach your stomach, your esophagus, or
"food pipe," travels down through the center of your chest and through
an opening in the diaphragm. This opening is called the hiatus.
Often as one ages, the hiatus enlarges. This allows the top portion
of the stomach to slip upward into the chest cavity. That portion
of the stomach which rises above the diaphragm is the hiatal hernia.
The name is derived from the fact that the stomach pushes, or herniates,
through the hiatus - hence the name "hiatal hernia." This condition
is quite common, but usually there are no symptoms. Activities or
conditions that increase pressure within the abdomen may worsen the
condition. These include persistent or heavy coughing, vomiting, straining
while having a bowel movement, extreme exercises to tighten the "abs,"
sudden physical straining, and pregnancy.
The food goes down OK, but now the powerful stomach acid splashes
up and damages the delicate lining of the lower esophagus. This condition
is common and given the name, Gastroesophageal Reflux Disease, or
GERD. See Heart
burning
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Sliding hernia Type I or sliding hiatal hernia
accounts for more than 95 percent of cases. This type of hernia is
characterized by widening of the muscular hiatal tunnel and circumferential
laxity of the phrenoesophageal membrane, allowing a portion of the
gastric cardia to herniate upward. The phrenoesophageal membrane remains
intact and the hernia is contained within the posterior mediastinum
In marginal instances, type I hiatal hernia is simply an exaggeration
of the normal phrenic ampulla, making its identification dependent
on measurement technique. However, when a sliding hiatal hernia enlarges
further, so that more than 3 cm of gastric pouch is herniated upward,
its presence is obvious regardless of technique because gastric folds
are evident traversing the diaphragm both during swallow-induced shortening
and at rest. The progression from normal anatomy to obvious type I
hernia is well illustrated in an analysis of the endoscopic appearance
of the cardia, as viewed from beneath with the endoscope directed
toward the hiatus
The etiology of most sliding hiatal hernias is speculative, but there
are instances in which trauma, congenital malformation, and iatrogenic
factors can be clearly implicated. The incidence of type I hiatal
hernia is also unclear. Estimates of prevalence vary enormously, from
10 to 80 percent .
In all probability, most small hiatal hernias are asymptomatic and,
even with larger type I hernias, the main clinical implication is
the propensity to develop gastroesophageal reflux disease (GERD).
The likelihood of symptomatic gastroesophageal reflux increases with
the size of the hiatal hernia. It is rare for complications other
than reflux to occur as a result of a type I hiatal hernia; furthermore,
even these complications are usually related to reflux. |
SYMPTOMS Hiatal hernia is not a diagnosis that
is pursued in and of itself. It is usually discovered as a finding
on upper gastrointestinal studies or endoscopy. Many patients with
a type II hernia are either asymptomatic or have only vague, intermittent
symptoms. The most common symptoms are epigastric or substernal pain,
postprandial fullness, substernal fullness, nausea, and retching.
An upright radiograph of the thorax may be diagnostic, revealing a
retrocardiac air-fluid level within a paraesophageal hernia or intrathoracic
stomach. Barium contrast studies are almost always diagnostic.
Most complications of a type II hernia are reflective of the mechanical
problem caused by the hernia. Type II, III, and IV: Paraesophageal
hernias
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| Association of type I hiatus hernia with gastroesophageal
reflux Endoscopic and radiographic studies suggest that 50
to 94 percent of patients with GERD have a type I hiatal hernia compared
to 13 to 59 percent of normals. However, the importance of a type
I hiatal hernia is obscured by the misconception that this is an all
or none phenomenon. It is more useful to view type I hiatal hernia
as a continuum of progressive disruption of the gastroesophageal junction
. Type I hiatus hernia impacts on reflux both by affecting the competence
of the gastroesophageal junction in preventing reflux and in compromising
the process of esophageal acid clearance once reflux has occurred.
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