Summary
Volvulus is defined as the twisting of a loop of bowel on its mesentery and is one of the most common causes of intestinal obstruction. The sigmoid colon, and less frequently, the cecum, are the common sites of volvulus in adults. Volvulus in a neonate or infant almost always presents as a midgut volvulus secondary to intestinal malrotation. Patients typically show features of bowel obstruction (abdominal pain, distension, bilious vomiting) or of bowel ischemia and gangrene (tachycardia, hypotension, hematochezia, peritonitis) in severe cases. The whirl sign and a grossly dilated loop of bowel on an abdominal CT scan establish the diagnosis of volvulus in adults. Upper GI series is the investigation of choice in infants with suspected midgut volvulus, which is seen as a cork-screw duodenum. Sigmoid volvulus without peritonitis is initially managed with endoscopic detorsion, followed by a semi-elective surgery (sigmoid colectomy). Sigmoid volvulus with peritonitis, and all cases of cecal volvulus, require emergency surgery. Endoscopic detorsion should not be attempted in a patient with cecal volvulus because of the high risk of perforation. The Ladd procedure (laparotomy and detorsion of the volvulus) is indicated in all patients with intestinal malrotation since it is impossible to predict if volvulus of the midgut will occur in an asymptomatic patient or not.
Epidemiology
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Incidence
- Volvulus: 3rd most common cause (∼ 10–15%) of intestinal obstruction in the United States
- Intestinal malrotation: symptomatic malrotation (midgut volvulus) in 1:6000 live births in the United States
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Age [1][2]
- Sigmoid volvulus: ∼ 70 years
- Cecal volvulus: 40–60 years
- Intestinal malrotation and midgut volvulus: neonates and infants
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Sex [1][2]
- Sigmoid volvulus: ♂ > ♀
- Cecal volvulus: ♀ >♂
SigmOid volvulus is more common in Older individuals while Midgut volvulus and Malrotation are more common in Minors.
Epidemiological data refers to the US, unless otherwise specified.
Pathophysiology
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Torsion of bowel on its axis [3]
- Closed-loop mechanical bowel obstruction → accumulation of gas and feces within the loop → increased intraluminal pressure → impaired capillary perfusion of bowel → bowel strangulation, ischemia, and gangrene
- Torsion of the mesenteric vascular pedicle → occlusion/thrombosis of mesenteric vessels → bowel strangulation, ischemia, and gangrene
- Location: may affect all parts of the bowel [4]
- Sigmoid volvulus (most common, 80%)
- Cecal volvulus (15%)
- Transverse colon volvulus (3%)
- Splenic flexure volvulus (2%)
Risk factors
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Long mesentery [5]
- Acquired (sigmoid volvulus): chronic constipation , high-fiber diet resulting in bulky stools → chronic overloading of the sigmoid colon → lengthening of the sigmoid colon and its mesentery → increased risk of torsion
- Congenital (cecal volvulus): abnormally mobile cecum → predisposition of the cecum to rotate on its axis (axial torsion) or fold upwards (cecal bascule)
- Intestinal malrotation: abnormal rotation of the bowel with abnormal fixation of mesentery to the posterior abdominal wall
- Megacolon (Hirschsprung disease, Chaga disease)
- Intestinal bands/adhesions
- Decreased pelvic space: pregnancy or pelvic mass
- Previous history of volvulus
Sigmoid volvulus
Clinical features
- Previous episodes of abdominal pain, which decreased after explosive passage of stool/gas
- Slowly (most common) or rapidly progressive symptoms of bowel obstruction
- If bowel ischemia occurs → tachycardia, hypotension, peritonitis (rebound tenderness), hematochezia or blood on DRE may be present
- If bowel perforation occurs → obliteration of liver dullness on percussion
Differential diagnoses
- Acute megacolon
- Toxic megacolon
- Other causes of mechanical bowel obstruction (e.g., colon cancer, strictures, cecal volvulus)
Treatment [6][7]
- Initial resuscitation: IV fluids; acid-base and electrolyte imbalance correction; NPO; placement of a nasogastric tube
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Evaluation
- No signs of peritonitis ; : rigid/flexible sigmoidoscopic detorsion of the volvulus → inspection of the mucosa for signs of ischemia [8]
- Signs of peritonitis/unsuccessful endoscopic detorsion → broad-spectrum IV antibiotics and emergency surgery [8]
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Surgery
- Sigmoid colectomy and primary anastomosis : indicated in hemodynamically stable patients with viable bowel [7]
- Hartmann procedure: indicated in hemodynamically unstable patients or those with ischemic/gangrenous bowel
References:[3][6][7][8][9][10][11]
Cecal volvulus
Types [12]
- Axial torsion of the cecum (90% of cases): the cecum rotates on its mesenteric axis → bowel obstruction with vascular compromise
- Cecal bascule (10%): the cecum folds upwards onto the ascending colon → bowel obstruction often without vascular compromise
Clinical features
- Acute presentation: features of small bowel obstruction
- Insidious onset: recurrent episodes of right lower abdominal pain
Differential diagnoses
- Sigmoid volvulus
- Small bowel obstruction (e.g., adhesions, tumors, intussusception)
Treatment [10]
- Initial resuscitation (See “Treatment” of sigmoid volvulus above.)
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Surgery
- Hemodynamically stable patients: ileocecal resection or right colectomy with ileocolic anastomosis
- Hemodynamically unstable patients
Intestinal malrotation and midgut volvulus
Definition
- Intestinal malrotation: arrest in the normal rotation of the gut in utero, resulting in an abnormal orientation of the bowel and mesentery within the abdominal cavity
- Normal intestinal rotation: the midgut starts to elongate in utero (4th week) → herniation of the midgut out of the umbilicus (6th week) → 90° counter-clockwise rotation of the midgut → re-entry of the midgut into the abdominal cavity(10th week) → 180° rotation inside the abdominal cavity (a total of 270°) → fixation of the duodenojejunal flexure and cecum to the posterior abdominal wall
Common types of intestinal malrotation [6][14][15] | |
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Nonrotation | Incomplete rotation |
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- Midgut volvulus: torsion of a malrotated midgut causing mechanical bowel obstruction, mostly in neonates and infants
Clinical presentation
- Malrotation: mostly asymptomatic
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Midgut volvulus
- Bilious vomiting with abdominal distension in a neonate/infant
- Signs of bowel ischemia: hematochezia, hematemesis, hypotension, and tachycardia
- Features of duodenal obstruction: bilious vomiting without abdominal distension
- Variable presentation in older children/adults: recurrent episodes of abdominal pain and vomiting; failure to gain weight; malabsorption [15][16]
- Abdominal examination is unreliable in neonates/infants because abdominal tenderness/rebound tenderness is difficult to assess in this population.
- Features of associated congenital anomalies
- Commonly associated anomalies: congenital diaphragmatic hernia (∼ 100%) ; congenital heart defects (up to 90%); omphalocele (up to 45%)
- Less commonly associated anomalies: gastroschisis; Meckel diverticulum; esophageal atresia; biliary atresia
Differential diagnoses [17][18]
- In neonates/infants with recurrent vomiting: duodenal atresia and stenosis; , hypertrophic pyloric stenosis
- In neonates with features of bowel ischemia/gangrene: necrotizing enterocolitis (NEC)
- In older children with abdominal pain and vomiting: intussusception
- In older children/adults with nonspecific symptoms: GERD; chronic mesenteric ischemia; food allergy
Treatment
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Midgut volvulus with/without peritonitis
- Initial resuscitation: NPO; nasogastric tube insertion; IV fluids; correction of electrolyte imbalance; broad-spectrum IV antibiotics
- Emergency surgery (Ladd procedure) [14]
- Incidentally detected/asymptomatic intestinal malrotation: elective surgery (Ladd procedure) [19]
References:[14][15][18][19][20]
Diagnostics
Volvulus
- Work-up follows the same protocol as that for bowel obstruction.
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Abdominal x-ray (erect and supine)
- Sigmoid volvulus: coffee bean sign (bent inner tube sign/inverted U sign)
- Cecal volvulus: kidney bean sign
- Cecal bascule: dilated cecum in the center of the abdominal cavity; an air-distended appendix may also be seen
- Bowel perforation: air under diaphragm [21]
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CT scan
- Whirl sign: pathognomonic for volvulus [22]
- Specific features of sigmoid/cecal volvulus are similar to those seen in x-rays
- Demonstrates bowel ischemia , or perforation , if present
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Barium enema: : bird's beak sign (tapering of the dye column at the site of the twist)
- In cecal bascule, the end of the barium column is rounded, rather than tapered (teardrop sign).
- Cecal volvulus: normal-sized colon with bird's beak sign at the cecum; dye does not enter the small bowel
- Sigmoid volvulus: normal-sized rectum with bird's beak sign at the sigmoid; dye does not enter the sigmoid colon
Intestinal malrotation and midgut volvulus
- Laboratory studies: complete blood count; electrolyte levels; arterial blood gas analysis [23][24]
Imaging in intestinal malrotation and midgut volvulus | ||
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Midgut volvulus | ||
Upper GI series (gold standard in hemodynamically stable patients) [15][25] |
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Barium enema (lower GI series) |
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Abdominal ultrasound [26] |
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CECT scan (oral and IV contrast)
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Abdominal x-ray |
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References:[15][21][22][23][24][25][26][27][28]
Differential diagnoses
See “Differential diagnosis of lower gastrointestinal bleeding in children.”
The differential diagnoses listed here are not exhaustive.