Malrotation & Volvulus in a child

Question 1

List some differentials for bilious vomiting in an infant.

Answer 1

• Duodenal/jejunal/ileal atresia
• Malrotation with volvulus
• NEC
• Meconium ileus

Question 2

What is the pathophysiology of malrotation?

Answer 2

Error which occurs during rotation of the small bowel in fetal life

The mesentery is not fixed at the duodennojejunal (DJ) flexure or in the ileocaecal region causing its base to be shorter than normal and predisposing to volvulus

Ladd bands which are peritoneal bands, may form and cross the duodenum anteriorly causing obstruction

Question 3

What are the two typical presentations of malrotation?

Answer 3

1. Obstruction
2. Obstruction with compromised blood supply

Obstruction usually presents with billous vomiting in the first few days of life but may also occur at a later age, abdominal pain and tenderness from peritonitis or ischaemic bowel.

Question 4

When does malrotation present?

Answer 4

Usually 3-7 days after birth, volvulus with compromised circulation may result in peritoneal signs and haemodynamic instability

Can also present at any age with volvulus

Question 5

What investigations are used to diagnose malrotation with volvulus and what do they show?

Answer 5

Upper GI contrast study - may show DJ flexure is more medially placed; this should be done for any child with billous vomiting.

USS - midline abdominal mass; may show abnormal orientation of SMA and SMV; ‘whirlpool sign’ on colour Doppler of blood flow in the superior mesenteric vein;

NB: if there are signs of vascular compromise then an urgent laparotomy is needed instead.

CT would show ‘coffee bean’ sign in sigmoid volvulus and would confirm malrotation by identifying the position of the mesenteric vessels.

Question 6

What do laboratory investigations show in malrotation with volvulus?

Answer 6

• Dehydration - fluid may migrate into bowel lumen and interstitial space and in such patients, dehydration can occur without diarrhoea and vomiting
• Hyponatraemia
• Hyperkalaemia
• Metabolic acidosis
• High urea and creatitine
• Hypochloraemia
• Lactic acidosis

Question 7

What is the definitive treatment for malrotation?

Answer 7

Ladd’s procedure

At operation with volvulus, the volvulus is untwisted, duodenum mobilised, bowel placed in non-rotated position with duodenojejunal flexure on the right and caecum and appendix on the left. Appendix is generally removed to aoid confusion at lateer presentations. Malrotation is not ‘corrected’ but the mesentery is broadened.

Question 8

What is a serious complication of malrotation with volvulus if left untreated?

Answer 8

Infarction of the entire midgut - sepsis - death

With volvulus this occurs as the superior mesenteric arterial blood supply to the small intestine + proximal large intestine is compromised and unless it is corrected it will lead to infarction of these areas.

If infarcted –> short gut syndrome - if infarcted and removed, problems surrounding parenteral nutrition will be present for life e.g. line sepsis, hepatobiliary dysfunction, growth restriction.

If untreated –> chronic intermittent volvulus - malabsorption with constipation interspersed with diarrhoea

Question 9

Should you surgically correct asymptomatic volvulus in children/adults?

Answer 9

Yes in children - prevent the serious complication of volvulus

No evidence in adults