Description

Volvulus represents an abnormal rotation (torsion) of the viscera that results in ischemia. Gastric, cecal, and midgut volvulus can occur. Midgut volvulus is the most common form in infants and children and is an acute complication of malrotation in which the viscera twist around the superior mesenteric artery (SMA).

Epidemiology

• Malrotation with midgut volvulus occurs in 1 in 6,000 live births.
• Because malrotation can be asymptomatic, the true incidence and prevalence are not known.
• Malrotation with volvulus is slightly more common in boys.
• Most children with midgut volvulus present in the 1st month of life.
• Malrotation can present at older ages, even in adulthood.

Risk Factors

• Children with malrotation have a narrow mesenteric vascular pedicle and are predisposed to volvulus around the SMA.
• Familial associations of malrotation can occur.
• The risk of volvulus in patients with malrotation does not decrease with age.

Etiology

• Malrotation occurs due to failure of the fetal gut to undergo normal in utero rotation and fixation resulting in a narrow mesenteric vascular pedicle.
• Volvulus occurs when the viscera twist around the narrow vascular pedicle (i.e., the SMA) resulting in intestinal ischemia.

Commonly Associated Conditions

• Nearly 100% of infants with congenital diaphragmatic hernia have some form of malrotation.
• Congenital heart disease is associated with malrotation in about 40–90% of cases, especially in the setting of heterotaxy.
• 31–45% of infants with omphalocele have malrotation.