Page 160 - Medicine and Surgery

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156 Chapter 4: Gastrointestinal system

Complications Aetiology
Hernias are irreducible when the contents cannot be Factors include hiatus hernia, pregnancy, obesity, ex-

manipulated back into the abdomen. Irreducibility cessive alcohol ingestion, cigarette smoking, coffee, red
(incarceration) is more likely if the neck of the sac wine, anticholinergic drug, oesophageal dysmotility and
is narrow (e.g. femoral and paraumbilical hernias) or systemic sclerosis.
if the contents become distended. Obstruction of the
intestinemayoccurcausingabdominalpain,vomiting Pathophysiology
and distension. The lower oesophageal sphincter is formed of the distal
Strangulation denotes compromise of the blood sup-
few centimeters of the oesophageal smooth muscle. Nor-
ply of the contents and significantly increases mor- mally after the passage of a food bolus the muscle rapidly
bidity and mortality. The low-pressure venous system contracts preventing reflux. Sphincter tone can increase
obstructs first, the resultant back pressure results in in response to a rise in intra-abdominal or intra-gastric
arterial insufficiency, ischaemia and ultimately infarc- pressure.
tion. Reflux results from low resting tone of the lower oe-
sophageal sphincter and failure of increase in tone to
rises in pressure further down the GI tract.
Investigations
The normal squamous epithelium of the oesophagus
These are rarely necessary to make the diagnosis, al-
issensitivetotheeffectsofacidandthusacuteinflamma-
though imaging such as ultrasound is sometimes used.
tion may be caused, called reflux oesophagitis. Contin-
uing inflammation may manifest as ulceration, scaring,
Management fibrosis and stricture formation.
Surgical treatment is usually advised electively to reduce Continuing inflammation may result in glandular ep-
the risk of complications. However, longstanding, large ithelial metaplasia (a change from the normal squamous
herniaswhicharerelativelyasymptomaticmaybetreated epitheliumtoglandularepithelium)termedBarrett’soe-
conservatively, as they have a low risk of incarceration sophagus, which predisposes to neoplasia.
and strangulation. Treatment can be by open or laparo-
scopic repair. Direct hernias are reduced and the defect Clinical features
closed by suture or synthetic mesh. Indirect hernias are Patients complain of symptoms of dyspepsia (see ear-
repaired by surgical removal of the herniation sac from lier in this chapter) particularly heartburn, a retroster-
the spermatic cord. If the internal ring is enlarged it is nal burning pain aggravated by bending or lying down.
reduced surgically. For other hernias, the principle is to Effortless regurgitation of food and acid (waterbrash)
excise the sac and obliterate the opening either by sutur- into the mouth may occur.
ing or mesh.
Investigations
Patients should be investigated as for dyspepsia in-
Prognosis
cluding upper GI endoscopy where appropriate (see
The recurrence rate of direct inguinal hernias is approx-
page 147).
imately 10%, but less with mesh techniques.
Barium swallow may show a hiatus hernia, true reflux
of barium must be demonstrated to be diagnostic. A
negative test however does not exclude reflux.
Disorders of the oesophagus 24-hour intraluminal pH monitoring is a gold stan-
dard test for acid reflux.
Gastrooesophageal reflux disease
Management
Definition Patients are managed as for dyspepsia, i.e. patients un-
Reflux of acidic gastric contents into the oesophagus via der the age of 55 years without ‘alarm symptoms and
the lower oesophageal sphincter. signs’ (see page 143) are treated without endoscopy.