What is Volvulus?
Volvulus is a twisting of the intestine or colon around its mesentery, resulting in intestinal obstruction and/or ischemia. 1
Anatomical Definition and Pathophysiology
- Volvulus occurs when a segment of bowel rotates around its mesenteric axis, leading to mechanical obstruction and potential vascular compromise 1, 2
- The twisting motion can compromise both the intestinal lumen (causing obstruction) and the mesenteric blood vessels (causing ischemia), making this a surgical emergency 3
Common Sites of Occurrence
- Sigmoid colon is the most frequently affected site, followed by the cecum, small intestine, and stomach 1
- Colonic volvulus accounts for 10-15% of all large bowel obstructions in the United States 3
- Sigmoid volvulus is the third leading cause of colon obstruction in adults 4
Key Anatomical Predispositions
For Sigmoid Volvulus:
- A redundant, elongated sigmoid colon (dolicho-sigmoid) on a narrow mesenteric base is the primary anatomical predisposition 5, 4
- The combination of a high, wide meso-sigmoid with a narrow root allows the bowel to twist around itself 5
- Chronic constipation and frequent laxative use contribute to the development of this elongated anatomy 5
For Cecal Volvulus:
- Occurs when the cecum is abnormally mobile due to incomplete peritoneal fixation 6
- Typically affects younger patients (age ≤60) compared to sigmoid volvulus 5
Clinical Significance and Complications
- Morbidity and mortality from colonic volvulus are high, making prompt diagnosis and treatment essential 3
- Major complications include hemorrhagic infarction, perforation, septic shock, and death 4
- Overall mortality ranges from 14-45%, with emergency surgery carrying 12-20% mortality versus 5.9% for elective resection 7, 4
- Without definitive treatment, sigmoid volvulus has a recurrence rate of 45-71% 7, 6
Critical Distinction: Small Bowel vs. Colonic Volvulus
- Midgut (small bowel) volvulus requires immediate emergency surgery and should not be confused with sigmoid volvulus, which can often be managed initially with endoscopic decompression 6
- Small bowel volvulus represents only 1% of all small bowel obstructions, with 0.82% associated with congenital malrotation 8