Malrotation

Malrotation of the bowel is the commonest non-syndromic anomaly associated with OA/TOF. During normal foetal development (week 6 gestation), the bowel herniates into the umbilical cord then returns back into the body, rotating as it does so. In malrotation, this goes wrong in a number of possible ways, resulting in the bowel being wrongly positioned and/or fixed incorrectly. This can cause severe twisting, causing disruption to blood flow to the bowel, volvulus and death of a large part of bowel. (52, 64–66)

Prevalence of malrotation in the presence of OA/TOF varies in different studies between 3% and 5% (71–73). This compares to a population prevalence of 1 in 500. Most present at less than 1 month old with vomiting, but can present later, including adulthood. In this instance, it can be with non-specific symptoms like diarrhoea, abdominal colic, recurrent vomiting, but also volvulus and intestinal herniation is possible. (74)

Symptoms

This can vary from vague symptoms post eating to an acute abdomen. These milder symptoms may have persisted for many years undiagnosed: (75)

• Vague abdominal pain, especially post meals
• Diarrhoea
• Abdominal colic
• Recurrent vomiting (74)

Risks

This can present as an acute surgical emergency such as:

• Intestinal ischaemia (non-localised pain disproportionate to examination findings, vomiting, anorexia and diarrhoea progressing to constipation, abdominal distension and GI bleedings, progressing to sepsis and shock) (76)
• Intestinal herniation
• Acute bowel obstruction (nausea and vomiting [including bilious vomiting], constipation and absence of flatus, distended abdomen, fever and tachycardia in later stages) (77)
• Volvulus (abdominal distension, vomiting green bile, constipation, abdominal pain, shock) (78)

Diagnosis

• Upper GI contrast series (Gold standard)
• CT scan with IV and oral contrast (unless volvulus suspected)
• Abdominal X-ray not helpful
• Full blood count may be normal unless extended period of volvulus (79)

Treatment

This is surgical – Ladd’s procedure which reduces volvulus, removal of Ladd’s bands, and widening of the mesenteric base to prevent the bowel twisting again.

Assessment of nutritional status and treatment of any deficiencies.

Long-term complications

• Short bowel syndrome, if volvulus etc have necessitated bowel resection (see section in Long-gap oestophageal atresia section).
• Volvulus following Ladd procedure – there is still a risk of volvulus even post Ladd procedure, so this should be considered even in those with malrotation repaired in childhood.
• Small bowel obstruction following Ladd procedure secondary to adhesions. Similarly, this may occur in those with malrotation diagnosed and repaired at any age.
• Malabsorption – this can be part of short bowel syndrome when bowel has been removed due to ischaemia or volvulus. This can result in iron, B12 and folate deficiency. It can also result from chronic volvulus and ischaemia in undiagnosed malrotation. (79)