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Sigmoid Volvulus

Contents

1. Background
2. Incidence
3. Aetiology
4. Pathology
5. Symptoms & Signs
6. Diagnosis & Investigation
   1. Abdominal X-Ray
   2. Water Soluble Enema
7. Management
   1. Conservative Management
      1. Flatus tube decompression
      2. Colonoscopic decompression
   2. Surgical Management

1. Background

• Most common volvulus of the GI tract

• Accounts for 5% of the causes of large bowel obstruction

2. Epidemiology

• Increased incidence in South America, Africa and parts of Asia

• More common in children where roundworm is endemic

   

3. Aetiology

• Risk factors include

  • Anatomic defect (see pathology)

  • Age (more common in the elderly)

  • Male

  • High fibre diet

  • Chronic constipation

  • Patients from nursing home or mental health institutions

  • Mobile sigmoid colon

4. Pathology

• Redundant loops of sigmoid colon on a long mesentery

• Narrow band attaching the posterior abdominal wall to the sigmoid mesentery predisposes patients to twisting of the sigmoid colon upon its axis

5. Symptoms & Signs

• Symptoms and signs are of those of large bowel obstruction
  • Abdominal pain

  • Absolute constipation

  • Abdominal distension

  • Empty rectum on DRE

• Examine closely for signs of ischaemia e.g. PR bleeding

6. Diagnosis & Investigation 

• Diagnosis is made by a combination of history, examination and imaging

• Delay in diagnosis can lead to ischaemia and perforation

• Digital Rectal Exam (DRE)

• Bloods: FBC, U&E's

6.1 Abdominal X-Ray

• Compression of the medial walls of the two sigmoid loops produces the pathognomonic "coffee bean sign"

• Loops of colon converge in the left hand side of the pelvis with loop extending to the right upper quadrant

6.2 Water Soluble Enema

• May show the "birds beak" sign where contrast stops at the point of convergence of the loops

• Confirms the diagnosis

7. Management

7.1 Conservative Management

7.1.1 Flatus tube decompression

• Indicated in the elderly and in those with no signs of ischaemia

• Place patient into left lateral decubitus position

• Under endoscopic control with rigid sigmoidoscopy a soft rubber flatus tube is passed through the obstruction

• Tube is left in place for 48 hours

7.1.2 Colonoscopic decompression

• Indicated for patients unfit for surgery and in whom flatus decompression using rigid sigmoidscopy has failed

7.2 Surgical Management

• Indications
  • Perforation

  • Ischaemia

  • Failed tube decompression

  • Repeated volvulus - prophylaxis against recurrence

• Surgical options include
  • Sigmoid colectomy and primary anastomosis

  • Hartmann's procedure - in the presence of ischaemia/perforation