Intestinal malrotation is a failure of the GI tract to undergo normal rotation around mesenteric vessels during embryogenesis.
- Asymptomatic malrotation is present in ~ 1 in 500 births.
- Symptomatic malrotation (midgut volvulus) occurs in 1:6000 neonates.
- 30% will present by 1st month, and 58% by 1 year of life.
- Boys = Girls
- Up to 62% will have another congenital anomaly:
- Congenital diaphragmatic hernia (most common)
- Congenital heart disease
- Intestinal/esophageal/biliary atresia
- Anorectal malformations
- Meckel’s diverticulum
- Failure of normal 270° counterclockwise rotation of the GI tract during the 4th–8th week of embryological development around the superior mesenteric axis.
- Resulting in abnormal intestinal attachments and anatomic positions
- A spectrum of rotational abnormalities can result.
Malrotation represents a spectrum of rotational abnormalities. The 2 most common abnormalities are complete nonrotation and incomplete rotation.
- Small bowel is on the right and colon is on the left.
- If the mesentery has a narrow base, clockwise twisting may result in midgut volvulus.
- When the mesenteric base is wide, there is not a high risk for volvulus.
- Cecum is in the mid-upper abdomen.
- Cecum fixated to the right lateral abdominal wall with Ladd’s bands (peritoneal attachments).
- Ladd’s bands cross the duodenum and may cause extrinsic compression.
- This configuration can also result in midgut volvulus as well as internal hernias.
- Twisting of the mesentery of malrotated small intestine
- Small bowel obstruction and ischemia will result.
- An acute presentation in infants most commonly results in a surgical emergency, but chronic/subacute cases can also occur in older individuals.
Malrotation (without volvulus)
- Mostly asymptomatic
- Duodenal obstruction (from Ladd’s bands):
- Forceful bilious vomiting
- Sometimes non-bilious, if obstructed proximally to the ampulla of Vater
- Infants and young children:
- Bilious vomiting
- Abdominal distension/tenderness: variable
- Late signs (indicating bowel ischemia):
- Hematochezia or rectal bleed
- Pale skin with diaphoresis
- Older children/adults:
- Insidious onset
- Intermittent abdominal pain and vomiting (bilious or nonbilious)
- Failure to gain weight due to malabsorption
- Chronic diarrhea
- Can also present with intermittent abdominal pain/vomiting
- Intermittent constipation
- Diagnosis is often missed/delayed
- Acute onset of bilious vomiting in infants
- Older children:
- Failure to thrive/failure to gain weight
- Chronic abdominal pain/vomiting/diarrhea
- Acute onset of abdominal pain and vomiting
- Abdominal tenderness (may be difficult to elicit in infants)
- Abdominal distention (variable)
- Signs of infant distress:
- Drawing up of knees to the abdomen
- Signs of dehydration
- Dry mucous membranes
- Sunken fontanelles
- Late signs indicating ischemia/perforation:
- Peritonitis/rigid abdomen
- Anemia (in chronic cases)
- Contraction alkalosis, electrolyte abnormalities from vomiting
- Acidosis, elevated lactate: signs of bowel ischemia
Should only be performed in stable patients. Patients with hemodynamic instability/sepsis/peritonitis should proceed to emergent surgery.
- Should be performed to rule out perforation in infants
- May show double-bubble sign (duodenal obstruction)
Upper GI series (UGI):
- Gold standard in hemodynamically stable patients
- The duodenojejunal segment (ligament of Treitz) is to the right of the midline.
- Duodenum has a “corkscrew” appearance (indicates volvulus).
- Dilated duodenum in cases of extrinsic compression or volvulus.
- Twisting of the superior mesenteric vein and the mesentery around the superior mesenteric artery is known as the “whirlpool” sign.
- Abnormal superior mesenteric artery/vein relationship
- Abnormal position of 3rd portion of the duodenum
- Dilated duodenum
- Normal ultrasound does not rule out malrotation.
- Fluid resuscitation/electrolyte correction
- Nils per os (nothing by mouth)
- Intravenous antibiotics to cover bowel flora
- Nasogastric tube insertion for gastric decompression
- Performed for all cases of midgut volvulus.
- Procedure consists of:
- Counterclockwise reduction of midgut volvulus
- Division of Ladd’s bands
- Broadening of the mesentery (open folded mesentery like a book and divide congenital adhesions)
- Positioning the colon on left side and the entire small bowel on the right side to prevent any future recurrence of volvulus
- Resection of any necrotic bowel if present, possibly with stoma creation
Elective/prophylactic Ladd’s procedure:
- Should be performed in incidentally detected/asymptomatic intestinal malrotation
- Can be performed laparoscopically in the absence of volvulus
- Overall mortality after surgery: 3%–9%
- Mortality is near 0% for otherwise healthy children with no ischemia, but the mortality rate can increases if:
- Intestinal necrosis
- Associated congenital anomalies
- Risk of recurrent volvulus: 2%–8%
- If a large segment of the small intestine needs to be resected because of necrosis, short-gut syndrome may result.
- Duodenal atresia and stenosis: a congenital condition where there is an absence of normal duodenal lumen. This condition can present with recurrent vomiting, feeding intolerance, and failure to thrive. Abdominal X-ray shows a characteristic double bubble sign and a gasless distal bowel. Management relies on surgical correction.
- Hypertrophic pyloric stenosis: a hypertrophy of the pyloric sphincter muscle in infants. This condition presents after the 1st 3 weeks of life with projectile nonbilious vomiting. Diagnosis is made with ultrasound, and treatment is surgical pyloromyotomy.
- Intussusception: a condition in which 1 part of the intestine telescopes into another, usually resulting in bowel obstruction. Patients present with colicky abdominal pain, vomiting, and sometimes bloody (or currant-jelly) stools. Diagnosis in children is frequently established with ultrasound. Treatment in children typically involves non-operative reduction with an enema, with surgery being reserved for complicated cases.
- Bensard D.D. (2018). Intestinal Malrotation. Medscape. Retrieved February 17, 2021, from https://emedicine.medscape.com/article/930313-overview
- Brandt M.L. (2019). Intestinal malrotation in children. UpToDate. Retrieved February 17, 2021, from https://www.uptodate.com/contents/intestinal-malrotation-in-children
- Filston H.C., Kirks D.R. (1981). Malrotation – the ubiquitous anomaly. J Pediatr Surg. 16(4 Suppl 1), 614.
- Townsend C.M. Jr., Beauchamp R.D., Evers B.M., Mattox K. L. (2004). Sabiston Textbook of Surgery. 17th ed. (2109–2110).