Sigmoid volvulus
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A sigmoidSigmoid volvulus is a cause of large bowel obstruction and occurs when the sigmoid colon tortes on the sigmoid mesocolon.
Epidemiology
Large bowel volvulus accounts for ~5% of all large bowel obstructions, with ~60% of intestinal volvulus involving the sigmoid colon 6. It is more common in the elderly 7.
Clinical presentation
Symptoms are that of a large bowel obstruction - constipation, abdominal bloating, nausea and/or vomiting. Onset may be acute or chronic.
Pathology
Aetiology
There is a wide range of causes, some are region-specific 5:
- chronic constipation and/or laxative abuse
- fibre-rich diet (especially in Africa)
- Chagas disease (especially in South America)
Associations
- chronic neurological conditions (e.g. Parkinson disease, multiple sclerosis, pseudobulbar palsy)
- chronic psychiatric conditions (e.g. chronic schizophrenia)
Radiographic features
Sigmoid volvulus is differentiated from a caecal volvulus by its ahaustral wall and the lower end pointing to pelvis.
Plain film
Abdominal radiographs will demonstrated a large, dilated loop of colon, often with a few air-fluid levels. Specific signs include:
- coffee bean sign 5
- Frimann Dahl's sign - three dense lines converge towards site of obstruction
- absent rectal gas 5
Fluoroscopy
Although now uncommonly performed, a water soluble contrast enema exquisitely demonstrates this condition, with the appearances described as the bird of prey sign.
CT
- large gas-filled loop without haustral markings, forming a closed-loop obstruction 6, 7
- whirl sign - twisting of the mesentery and mesenteric vessels
- beak sign - if rectal contrast has been administered 6
Treatment and prognosis
Rectal tube insertion is successful in successful in treating 90% of cases 5. Mortality rate is 20-25% 7.
Differential diagnosis
- large bowel obstruction from other causes
- caecal volvulus
- colonic pseudo-obstruction
-<p>A<strong> sigmoid volvulus</strong> is a cause of <a href="/articles/large-bowel-obstruction">large bowel obstruction</a> and occurs when the <a href="/articles/sigmoid-colon">sigmoid colon</a> tortes on the <a href="/articles/sigmoid-mesocolon">sigmoid mesocolon</a>.</p><h4>Epidemiology</h4><p>Large bowel volvulus accounts for ~5% of all large bowel obstructions, with ~60% of <a href="/articles/intestinal-volvulus">intestinal volvulus</a> involving the <a href="/articles/sigmoid-colon">sigmoid colon</a> <sup>6</sup>. It is more common in the elderly <sup>7</sup>.</p><h4>Clinical presentation</h4><p>Symptoms are that of a large bowel obstruction - constipation, abdominal bloating, nausea and/or vomiting. Onset may be acute or chronic. </p><h4>Pathology</h4><h5>Aetiology</h5><p>There is a wide range of causes, some are region-specific <sup>5</sup>:</p><ul>- +<p><strong>Sigmoid volvulus</strong> is a cause of <a href="/articles/large-bowel-obstruction">large bowel obstruction</a> and occurs when the <a href="/articles/sigmoid-colon">sigmoid colon</a> tortes on the <a href="/articles/sigmoid-mesocolon">sigmoid mesocolon</a>.</p><h4>Epidemiology</h4><p>Large bowel volvulus accounts for ~5% of all large bowel obstructions, with ~60% of <a href="/articles/intestinal-volvulus">intestinal volvulus</a> involving the <a href="/articles/sigmoid-colon">sigmoid colon</a> <sup>6</sup>. It is more common in the elderly <sup>7</sup>.</p><h4>Clinical presentation</h4><p>Symptoms are that of a large bowel obstruction - constipation, abdominal bloating, nausea and/or vomiting. Onset may be acute or chronic. </p><h4>Pathology</h4><h5>Aetiology</h5><p>There is a wide range of causes, some are region-specific <sup>5</sup>:</p><ul>
-</ul><h4>Radiographic features</h4><p>Sigmoid volvulus is differentiated from a <a href="/articles/caecal_volvulus">caecal volvulus</a> by its ahaustral wall and the lower end pointing to <a title="Pelvis" href="/articles/pelvis-1">pelvis</a>. </p><h5>Plain film</h5><p>Abdominal radiographs will demonstrated a large, dilated loop of colon, often with a few <a href="/articles/air-fluid-level">air-fluid levels</a>. Specific signs include:</p><ul>- +</ul><h4>Radiographic features</h4><p>Sigmoid volvulus is differentiated from a <a href="/articles/caecal-volvulus">caecal volvulus</a> by its ahaustral wall and the lower end pointing to <a href="/articles/pelvis-1">pelvis</a>. </p><h5>Plain film</h5><p>Abdominal radiographs will demonstrated a large, dilated loop of colon, often with a few <a href="/articles/air-fluid-level">air-fluid levels</a>. Specific signs include:</p><ul>
-<a href="/articles/coffee-bean_sign">coffee bean sign</a> <sup>5</sup>- +<a href="/articles/coffee-bean-sign-3">coffee bean sign</a> <sup>5</sup>
-</ul><h5>Fluoroscopy</h5><p>Although now uncommonly performed, a water soluble contrast enema exquisitely demonstrates this condition, with the appearances described as the <u>bird of prey sign.</u></p><h5>CT</h5><ul>-<li>large gas-filled loop without <a title="Haustral markings" href="/articles/haustral-markings">haustral markings</a>, forming a <a href="/articles/closed-loop-obstruction">closed-loop obstruction</a> <sup>6, 7</sup>- +</ul><h5>Fluoroscopy</h5><p>Although now uncommonly performed, a water soluble contrast enema exquisitely demonstrates this condition, with the appearances described as the bird of prey sign.</p><h5>CT</h5><ul>
- +<li>large gas-filled loop without <a href="/articles/haustral-markings">haustral markings</a>, forming a <a href="/articles/closed-loop-obstruction">closed-loop obstruction</a> <sup>6, 7</sup>
-<a title="beak sign of sigmoid volvulus" href="/articles/beak-sign-of-sigmoid-volvulus">beak sign</a> - if rectal contrast has been administered <sup>6</sup>- +<a href="/articles/beak-sign-of-sigmoid-volvulus">beak sign</a> - if rectal contrast has been administered <sup>6</sup>
-<li><a href="/articles/caecal_volvulus">caecal volvulus</a></li>- +<li><a href="/articles/caecal-volvulus">caecal volvulus</a></li>
Images Changes:
Image 11 CT (C+ portal venous phase) ( create )
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