(5) Sigmoid volvulus

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Large bowel obstruction, occurs when the sigmoid colon twists on its mesentery, the sigmoid mesocolon

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5% of large bowel obstruction in developed countries, and 10~50% in developing countries

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Risk factor:
Chronic constipation and/or laxative abuse
Fiber-rich diet
Redundant colon
Medication from chronic psychiatric conditions

A. Clinical presentation

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Abdominal pain (initially left-sided, later diffuse)

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Enormous abdominal distension

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Constipation

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Nausea & vomiting

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Whirl pattern, caused by the dilated sigmoid colon around its mesocolon & vessels

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Bird-beak appearance of the afferent and efferent colonic segments

⇒ may absent in one-fourth of CT scans

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Large gas-filled loop lacking haustra, forming closed-loop obstruction

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Whirl sign

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Bird beak sign

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X-marks-the-spot sign : complete obstruction 되면서 distal, proximal sigmoid colon이 둘 다 obstruction 되는데, 이 두 속의 transition point가 반대로 나타나서 마치 x표시 같다.

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Split wall sign : incomplete obstruction, partial obstruction시 distal, proximal colon 사이 mesenteric fat이 들어가며 마치 둘을 분리시키는 것 같다

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Steel pan sign

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U-shaped, distended sigmoid colon, a haustral collection of gas

⇒ extending from the pelvis to the right upper quadrant

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Only 60% of patients

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bird’s beak configuration

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Peritonitis 의심소견, 천공 의심소견 ⇒ 응급수술

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위 사항 없으면 내시경으로 detorsion 시도.

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Conservative treatment

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Rigid/Flexible sigmoidoscopy – decompress proximal bowel

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Recurrence: wide range (20~84%)

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Failure ⇒ urgent surgical management