Malrotation

Basics

Description

  • Incomplete rotation and fixation of intestine during embryogenesis during transition from extracolonic position during week 10 of gestation
  • Risk factor:
    • Heterotaxia syndromes
  • Associated conditions:
    • Gastrointestinal anomalies:
      • Duodenal stenosis, atresia, web
      • Meckel diverticulum
      • Intussusception
      • Gastroesophageal reflux
      • Omphalocele or gastroschisis
      • Congenital diaphragmatic hernia
      • Abdominal wall defect
      • Hirschsprung disease
    • Metabolic acidosis
    • Congenital cardiac anomalies present in 27% of patients with malrotation. Increases morbidity to 61%.

Etiology

  • Duodenojejunal junction remains right of midline
  • Cecum remains in the upper left abdomen with abnormal mesenteric attachments
  • Volvulus is a complication of malrotation when small bowel rotates around superior mesenteric artery and vein resulting in vascular compromise to midgut
  • Abnormal anatomy predisposes to obstruction and other conditions
  • Usually found in combination with other congenital anomalies (70%): Cardiac, esophageal, urinary, anal
  • Congenital cardiac anomalies are present in 27% of patients with malrotation
  • Epidemiology:
    • 1 in 500 live births
    • High mortality in infants: Up to 24%
    • Necrotic bowel at surgery increases mortality by 25×
    • Incidence:
      • In neonates, male-to-female ratio 2:1
      • 75% diagnosed newborn period
      • 90% diagnosed by age 1 yr of life
      • 10% may present after age 1 and can present during adulthood

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