Volvulus

Description

• Axial twist of a portion of the GI tract around its mesentery causing partial or complete obstruction of the bowel
• Often associated with other GI abnormalities
• In pediatric setting, infants typically involved:
  • Abnormal embryonic development
• Can be precipitated by pathologic distention of the colon
• Blood supply may be compromised by venous congestion and eventual arterial inflow obstruction, leading to gangrene of the bowel and potential infarction

Etiology

• Third most common cause of colonic obstruction (10–15%) following tumor and diverticular disease
• Epidemiology:
  • 0–1 yr old: 30%
  • 1–18 yr old: 20%
  • Over 18 yr old: 50%
• Often associated with other GI abnormalities
• Cecum (52%):
  • More common in young adults, <50 yr old
  • Due to improper congenital fusion of the mesentery with the posterior parietal peritoneum, causing the cecum to be freely mobile in varying degrees
  • Associated with increased gas production (malabsorption and pseudo-obstruction)
  • Can be seen in pregnancy and after colonoscopy
• Sigmoid (43%):
  • More common in:
    • Elderly
    • Institutionalized
    • Chronic bowel motility disorders (Parkinson)
    • Psychiatric diseases (schizophrenia)
  • Due to redundant sigmoid colon with narrow mesenteric attachment
  • Associated with chronic constipation and concomitant laxative use
• Transverse colon and splenic flexure (5%)
• Gastric volvulus (rare) associated with diaphragmatic defects

• Midgut volvulus:
  • Due to congenital malrotation in which the midgut fails to rotate properly in utero as it enters the abdomen
  • Entire midgut from the descending duodenum to the transverse colon rotates around its mesenteric stalk, including the superior mesenteric artery
  • Common in neonates (80% <1 mo old, often in first week; 6–20% >1 yr old)
  • Males > females, 2:1
  • Sudden onset of bilious emesis (97%) with abdominal pain
  • May have previous episodes of feeding problems/bilious emesis
  • In children >1 yr old, associated with failure to thrive, alleged intolerance to feedings, chronic intermittent vomiting, bloody diarrhea
  • Constipation
  • Mild distention, since obstruction higher in GI tract
  • May not appear toxic based on degree of ischemia