Introduction
Gut malrotation refers to an abnormal rotation and fixation of the midgut during embryological development. Normally, the midgut rotates 270° counterclockwise around the superior mesenteric artery (SMA). Failure of this process can result in life-threatening complications such as midgut volvulus.
Embryology Behind Malrotation
In normal development, the midgut rotates 270° counterclockwise around the SMA. In malrotation, this rotation is incomplete or abnormal. The consequences include:
- Narrow mesenteric base (prone to volvulus)
- Ladd’s bands compressing the duodenum
- Cecum abnormally placed (not in the right lower quadrant)
Clinical Presentation
Most neonates present in the first month of life, typically with:
- Bilious vomiting – the most important symptom
- Abdominal distension (may be minimal early on)
- Blood-stained stools
- Poor feeding and lethargy
- Signs of sepsis or shock in advanced stages
Red Flag: Any bilious vomiting in a neonate must raise strong suspicion of malrotation with volvulus.
Diagnosis
- Plain Abdominal X-ray: May show non-specific findings like a gasless abdomen or double bubble.
- Upper GI Contrast Study (Gold Standard):
- Shows abnormal position of the duodenojejunal junction
- May reveal the classic “corkscrew” appearance if volvulus is present
- Ultrasound:
- May show “whirlpool sign” – a twisted SMV around the SMA
Complications of Untreated Malrotation
If volvulus occurs and is not corrected in time, it can lead to:
- Midgut ischemia and necrosis
- Bowel perforation
- Short bowel syndrome (after resection)
- Septic shock and death
Management
Initial Stabilization Includes:
- IV fluids
- Nasogastric decompression
- Broad-spectrum antibiotics
Definitive Treatment – Ladd’s Procedure:
- Surgical detorsion of volvulus (if present)
- Division of Ladd’s bands
- Placement of small bowel on the right and colon on the left (non-rotated position)
- Appendectomy to prevent future diagnostic confusion
Prognosis
Early diagnosis and timely surgery lead to excellent outcomes. Delay increases risk of bowel loss and poor survival.
Key Points for Pediatricians
- Always consider malrotation with volvulus in a neonate with bilious vomiting
- Rapid diagnosis and surgical intervention are critical
- A simple upper GI contrast study can be life-saving
