What is sigmoid volvulus and how to manage it?

From the Guidelines

Sigmoid volvulus is a life-threatening condition that requires prompt recognition and management, with the first-line treatment being endoscopic decompression using a flexible sigmoidoscope, as recommended by the WSES consensus guidelines 1.

Definition and Pathophysiology

Sigmoid volvulus is a condition where the sigmoid colon twists around its mesenteric axis, causing bowel obstruction and potential ischemia. This occurs due to a redundant sigmoid colon with a narrow mesenteric attachment, most commonly affecting elderly, institutionalized patients and those with chronic constipation or neuropsychiatric conditions.

Management

Management begins with prompt recognition and initial stabilization with IV fluids, NPO status, and nasogastric tube placement.

• The first-line treatment is endoscopic decompression using a flexible sigmoidoscope to untwist the colon and place a rectal tube, which has a success rate of 70-90% 1.
• This procedure should be performed within 24 hours of presentation.
• If successful, the rectal tube should remain for 1-3 days.
• Definitive treatment requires sigmoid colectomy, ideally performed electively 2-3 days after successful decompression, as recurrence rates without surgery exceed 60% 1.
• Emergency surgery is necessary if endoscopic decompression fails, signs of peritonitis exist, or bowel ischemia is suspected.
• Surgical options include sigmoid resection with primary anastomosis or Hartmann's procedure depending on patient condition and bowel viability.

Importance of Early Intervention

Early intervention is crucial as mortality rates increase significantly with bowel ischemia or perforation.

• The decision to perform an isolated sigmoid colectomy versus a high anterior resection should be individualized, with consideration of the vascular supply of the remnant colon 1.
• The role of laparoscopic surgery for emergency colorectal operations is still unclear, but it may be a suitable alternative to laparotomy in select cases by surgeons who are competent with this technique 1.

Recurrence and Mortality

After colonoscopic detorsion followed by conservative management, the recurrence rate of sigmoid volvulus varies from 45 to 71% 1.

• The mortality after conservative treatment in the literature varies between 9% and 36% 1.
• Sigmoid colectomy is the intervention that is most effective at preventing recurrent volvulus, with low morbidity and mortality in the range of 0–12% 1.

From the Research

Definition and Causes of Sigmoid Volvulus

• Sigmoid volvulus is an uncommon cause of bowel obstruction that occurs when the sigmoid colon wraps around itself and its mesentery 2.
• The etiology of sigmoid volvulus is multifactorial and controversial, with symptoms including abdominal pain, distention, and constipation 2.

Diagnosis of Sigmoid Volvulus

• The diagnosis of sigmoid volvulus is established by clinical, radiological, endoscopic, and sometimes operative findings 2.
• Plain abdominal X-ray radiographs show a dilated sigmoid colon and multiple small or large intestinal air-fluid levels, while abdominal CT and MRI demonstrate a whirled sigmoid mesentery 2.
• Flexible endoscopy shows a spiral sphincter-like twist of the mucosa 2.

Management of Sigmoid Volvulus

• The primary treatment choice for sigmoid volvulus is flexible endoscopic detorsion, followed by elective surgery 2, 3.
• Emergency surgery is required for patients who present with peritonitis, bowel gangrene, or perforation, or for patients whose non-operative treatment is unsuccessful 2, 4.
• Resection with primary anastomosis is the most commonly recommended procedure for emergency surgery 2, 4.
• Early sigmoid colectomy is associated with low morbidity and is safe in the elderly, with reduced readmissions and a low complication rate 5.

Treatment Outcomes

• The overall mortality for sigmoid volvulus is 10% to 50%, while the overall morbidity is 6% to 24% 2.
• In selected patients, anastomosis without proximal diversion in patients with sigmoid volvulus results in similar outcomes to colectomy with end colostomy 6.
• The most important determinant of patient outcome is bowel viability 4.