Volvulus

Question 1

Define malrotation

Answer 1

Congenital abnormality of the midgut where there is a rotational and fixation disturbance occurring during embryonic development

Question 2

What is the most common malrotation deformity

Answer 2

Small intestine lies predominantly on the right hand side of the abdomen, with the caecum in the right upper quadrant

Question 3

What is the aetiology of malrotation and volvulus

Answer 3

Failure of the intestine to rotate into the correct position during foetal life and secure/fix the mesentery in the correct position.
Fibrous bands (Ladd bands) tether the caecum to the right upper quadrant → compression of the duodenum → intestinal obstruction
The poorly-tethered gut is able to swing and twist more readily → volvulus
Volvulus → compromise to the arterial blood supply of the small intestine and proximal large intestine e.g. superior mesenteric artery → infarction

Question 4

What are the risk factors for malrotation and volvulus

Answer 4

Male
BLC6 gene mutation
Young age (50-75% 1 month, 90% 1yo)

Question 5

What are the symptoms of malrotation and volvulus

Answer 5

<1yo: obstruction ± compromised blood supply (ischaemia/necrosis)

Bilious vomiting (sudden onset, green (dark green = urgent)
Abdominal pain: severe, sudden onset, may present as a notable transition to an inconsolable state
Weight loss (intermittent/partial volvulus or Ladd’s bands)
Dark blood in nappy

Question 6

What are the signs of malrotation and volvulus on examiantion

Answer 6

Obs
- Tachycardia with hypertension → hypotension (ischaemia)
- Tachypnoea (acidosis from infarction)
Abdominal exam
- Volvulus: Normal (distended abdomen is more commonly a bowel obstruction, vomiting and pain with a flat abdomen should alert to volvulus presence)
- Compromised blood supply: abdominal distension, tenderness
- Midgut volvulus: rebound tenderness and guarding (peritoneal)

Question 7

What investigations should be done for volvulus

Answer 7

Bloods: FBC (Raised WCC, polycythaemia), blood gas (metabolic acidosis + resp alkalosis), U&Es, LFTs, glucose
Other:
- Upper GI contrast study: Malrotation (right sided duodenum, which courses inferior medial to normal) or volvulus (bird-beak cut off of duodenum, corkscrew appearance)
- CT with contrast: No contrast beyond the point of volvulus
- AXR: Distended stomach and proximal duodenum with paucity of bowel gas seen distally

Question 8

What is the management for malrotation and volvulus

Answer 8

Dark green vomiting → urgent upper GI contrast study → urgent laparotomy and Ladd’s procedure
Signs of vascular compromise (obstruction with ischaemia) → urgent laparotomy and Ladd’s procedure
+. antibiotics (cefazolin)

Ladd’s = volvulus untwisted, duodenum mobilised and bowel placed in the non-rotated position with duodenojejunal flexure on the right, caecum and appendix on the left
± appendicectomy to avoid future confusion
laparoscopically (if elective or non-urgent) OR during open laparotomy (emergency or urgent)

Question 9

What are the complications of treatment for malrotation and volvulus

Answer 9

Short gut syndrome: When a large amount of small intestine must be resected to allow for survival due to a long segment of necrotic bowel, the survivors are likely to have inadequate bowel length. This will cause inability to sustain life and growth with enteric intake and require long-term parenteral nutrition.
Volvulus
Adhesive small bowel obstruction

Question 10

What are the complications of malrotation and volvulus

Answer 10

Superior mesenteric arterial blood supply compromised → infarction
Bowel ischaemia, necrosis, gangrene
Failure to thrive
Gastro-oesophageal reflux disease
Chronic obstructive symptoms

Question 11

What is the prognosis for malrotation and volvulus

Answer 11

After volvulus:
- Mortality 10%, depends on degree of intestinal necrosis
- Risk of recurrence is 10%

After Ladd’s procedure:
- Mortality determined by degree of bowel necrosis