Makindo Medical Notes

Related Subjects: Small Bowel Obstruction | Colonic (Large Bowel) Obstruction | Small Bowel Ischemia | Hartmann's Procedure | Sigmoid and Caecal Volvulus | Acute Colonic Pseudo-obstruction

Leading cause of acute colonic obstruction. Emergency endoscopic decompression, detorsion, and reduction (EDDR) aim to decompress the dilated colon and untwist the volvulus. EDDR is the treatment of choice in uncomplicated patients.

About

• A common cause of large bowel obstruction in older patients.

Aetiology

• Redundant loop of sigmoid colon with a narrow base of attachment to the mesosigmoid.
• Twisting of the sigmoid colon on its mesentery, called the sigmoid mesocolon.
• Derived from "volvere," meaning to twist or turn around its mesenteric axis.
• Partial or complete obstruction may result.
• Occlusion of the arteries at the base of the involved mesentery can lead to gangrene and perforation.
• The sigmoid colon is more commonly affected than the caecum.

Associations

• Age of onset: 60-70 years; Males more affected than females (M>F).
• Associated with Parkinson's disease, Multiple Sclerosis (MS).
• Chronic constipation, laxative abuse.
• Chagas disease, high-fiber diet.

Clinical Presentation

• Intermittent or absolute constipation, leading to obstruction.
• Colicky abdominal pain and distension.
• May progress to intestinal obstruction and/or peritonitis.
• Distended abdomen, fever, signs of shock if peritonitis is present.
• 40-60% of patients have a history of previous attacks.

Investigations

• Abdominal X-ray (AXR): Shows a large, dilated loop of the colon, often with gas-fluid levels.
• CT Scan: Displays large, gas-filled loops with evidence of bowel twisting.
• Barium enema: Shows a "bird’s beak" appearance, contraindicated if strangulation is suspected.

Management

• Initial Management: ABC, IV fluids, and nil by mouth (NBM). Correct electrolyte imbalances and consider nasogastric decompression if obstructed. Manage pain appropriately.
• Sigmoid Volvulus: Decompression with a flatus tube. Leave the tube in for 48 hours. If flatus tube decompression fails, attempt detorsion with rigid or flexible sigmoidoscopy, colonoscopy, and rectal tube placement. Be cautious as a large volume of feculent material may be released under pressure; ensure adequate protection.
• If peritonitis or other signs of ischaemia (raised WCC, lactate, temperature) are present, a laparotomy is necessary. Resection may be required, with a mortality rate of up to 25%, especially in cases of bowel ischaemia. Recurrence rates are high (40-50%), so follow-up procedures are needed.
• Caecal Volvulus: Requires caecal untwisting, usually through a caecostomy. If the bowel is gangrenous, a right hemicolectomy may be needed. Diagnosis is often delayed, contributing to a higher mortality rate.

References

• Sigmoid Volvulus Cases Presentation