Malrotation & Volvulus Flashcards
Define malrotation and volvulus.
Failure of normal embryological rotation of the small intestine around the superior mesenteric artery (SMA) during embryological development, predisposing to intestinal obstruction, volvulus and ischaemia.
Explain the aetiology/risk factors for malrotation and volvulus.
Normal rotation takes place around the SMA as the axis in three stages: stage I (herniation), stage II (return to the abdomen with 270 degree counter-clockwise rotation), stage III (fixation).
- Between the 4th to 8th weeks of development expansion of the GI tract causes the primary intestinal loop to buckle into the area of the yolk stalk.
- As the primary intestinal loop buckles it twists 90 degrees counterclockwise.
- The primary loop returns to the abdomen during the 8th to 10th week of gestation with an additional 180 degrees counterclockwise rotation.
- The proximal portion of the bowel is fixed to the retroperitoneum early in gestation, at the ligament of Treitz, whereas fixation of the colon is gradual and usually completed near term.
What is non-rotation?
Midgut only rotates 180 degree.
What is incomplete rotation (malrotation).
Duodenal loop lacks 90 degree and the caecocolic loop 180 degree of the normal 270 degree rotation.
What are malrotation and volvulus associated with?
- Gastroschisis
- Congenital diaphragmatic hernia
- Duodenal atresia
- Jejunoileal atresia
- Hirschsprung disease
- Gastrooesophgeal reflux
- Intussusception
Summarise the epidemiology of malrotation and volvulus.
1/500.
Common adult postmortem finding.
M: F.2 : 1 (neonatal), 1 : 1 >1 year.
What are the symptoms of acute mid-gut volvulus?
Usually presents <1 year old with sudden onset of bilious (bright green) vomiting, abdominal distension and severe pain.
What are the symptoms of chronic mid-gut volvulus?
Recurrent abdominal pain and malabsorption syndrome.
Between volvulus episodes, may appear normal.
What are the symptoms of acute duodenal obstruction?
Usually presents in infancy with forceful vomiting, abdominal distension and gastric waves.
2 to compression or kinking of the duodenum by Ladd bands.
What are the symptoms of chronic duodenal obstruction?
Usually presents in infancy–preschool with bilious vomiting.
Patients may also have failure to thrive and intermittent abdominal pain.
What are general symptoms of malrotation and volvulus?
Signs of bowel obstruction
Bilious vomiting in the neonate is an indication of malrotation until proven otherwise and is usually due to acute volvulus.
Chronic volvulus will involve recurrent abdominal pain and malabsorption, as well as diarrhea, constipation, and gastroesophageal reflux.
Acute duodenal obstruction occurs mainly in infants and involves the compression of the duodenum by Ladd bands. Patients demonstrate forceful vomiting.
Chronic duodenal obstruction may appear in older children (preschool-age). Other less common presentations can include failure to thrive, solid food intolerance, malabsorption, chronic diarrhea
What are differential diagnoses for malrotation and volvulus?
- Trauma
- Foreign body ingestion
- Poisoning
- Appendicitis
- Incarcerated inguinal hernia
- PUD
- Constipation
- Gastroenteritis
- UTI
- PID
- Ectopic pregnancy
What are signs of acute obstruction?
Tachycardia
Abdominal distension
Tinkling bowel sounds
What are the signs of infarction or necrosis?
Shock (“HR, pallor, increased CRT, decreased responsiveness), pyrexia and signs of acute peritonitis.
What are some appropriate investigations for malrotation and volvulus?
Bloods: FBC, U&E, Blood gas
Imaging: AXR (dilated loops of bowel or gasless abdominal field
UGI contrast: Should be performed on all infants with bright green bilious vomiting. Cork-screw appearance with volvulus or a duodenal-jejunal flexure to the right of the midline with malrotations (normal DJ - left of midline & level of pylorus).
