5. Paediatrics (GI) Flashcards
Oesophageal atreasia/TE fistula (7)
Can occur in mutiple subtypes, classically shown on frontal CXR with NG tube stopped in upper neck.
Fluoro: Lateral with blind ending sac or communication with tracheal tree.
5 main subtypes, 3 of which are worth knowing:
- N-type fistula - 85% (blind ended oesophagus with distal oesophagus connected to trachea)
- Oesophageal atresia with NO fistula - 10% (No air in stomach)
- H-type atresia - 1% (Excessive air in stomach.
Part of VACTERL associations.
Presence of right arch (4%) must be described prior to surgery as it changes the approach.
VACTERL (8)
Certain associations are seen more commonly when together.
VACTERL association diagnosed when 3 or more anomalies affect a patient.
Heart and kidneys are most commonly affected organs.
V - Vertebral anomalies (37%)
A - Anal (imperforate anus) (63%)
C - Cardiac (77%)
TE - Tracheo-oesophageal fistula or Esophageal atresia (40%)
R - Renal (72%)
L - Limb (radial ray) (58%)
Oesophageal foreign bodies (3)
Can cause compression, perf or even fistula of trachea.
On frontal CXR, a coin seen in coronal plane is more likely in oesophagus, whereas one rotated 90 degrees is more likely in trachea (must turn longways against elastic posterior membrane)
Swallowed magnets (3)
One magnet is OK.
Multiple is a problem, they can attract to each other across intestinal walls, causing obstruction, necrosis, perf.
Needs surgical input.
MRI is contraindicated.
Disc batteries (3)
Look like coins, except they have 2 rings.
Modern batteries rarely leak, so many will now watch it transit with sereal X-rays.
If it gets stuck, needs retrieval. Risk of leaking increases after a week or so.
Pennies (3)
Older (copper) ones are safe, newer ones are mostly zinc, which can cause gastric ulcerations when comvbined with stomach acid.
Can also cause zinc toxicosis if absorbed in great enough quantities (can cause pancreatic dysfunction/pancreatitis).
Question will likely indicate if the coin is particularly old, or show characteristic radiolucent holes in the coin from erosion.
Pulmonary sling (7)
Only anatomic variant that goes between the oesophagus and trachea.
Associated with tracheal stensosis.
Associated with other cardiopulmonary and systemic anomalies
- Hypoplastic right lung.
- TE fistula
- Imperforate anus
- Complete tracheal rings
Posterior indentation on trachea, anterior on oesophagus
Double aortic arch (2)
Commonest Symptomatic vascular ring anomaly.
Anterior indentation on trachea, posterior on oesophagus.
Left arch with aberrant right subclavian artery (3)
Commonest aortic arch anomaly, not necessarily symptomatic.
“Dysphagia Lusoria” - trouble swallowing in the setting of this variant anomaly.
“Diverticulum of Kommerell” - pouch like aneurysmal dilatation of the proximal portion of an aberrant right subclavian
Bowel obstruction in neonate (4)
Can be either high or low.
Neonate plus any of the following suggest obstruction
- Vomiting
- Abdo pain
- Hasn’t passed stool yet
Causes for “high” neonatal obstruction (5)
Midgut volvulus
Duodenal atresia
Duodenal web
Annular pancreas
Jejunal atresia
Causes of low obstruction (5)
Hirschprung disease
Meconium plug syndrome
Ileal atresia
Meconium ileus
Anal atresia/colonic atresia
Bubbles on AXR in paeds (8)
Normal - Gastric bubble in LUQ with smaller gas bubbles all over abdomen (bowel)
Single bubble - Single gastric bubble in LUQ
Double bubble - LUQ gastrc bubble plus smaller bubble midline and slightly inferior
Triple bubble - as above with third bubble below and left.
Single bubble with distal gas
Double bubble with distal gas
Diffusely dilated
Diffusely mildly dilated.
Single bubble - causes
Gastric (antral or pyloric) atresia
Double bubble causes (7)
Duodenal atresia (highly specific).
Some will say that UGI is not necessary because of how specific this is.
Degree of distension will be more pronounced than with midgut volvulus (which is more acute).
Due to secondary failure to canalize during development (often an isolated atresia)
30% have downs, 40% have polyhydramnios and are premature.
The “Single atresia” cannulation error
Double bubble can be shown on 3rd trimester US, plain film or MRI
Triple bubble - cause (3)
Jejunal atresia.
Search for additional atresias, e.g. colonic.
Jejunal atresia is often secondary to vascular insult during development.
Single bubble with distal gas - cause (3)
Can mean nothing (air swallowing).
If clinical HX is bilious vomiting, can be midgut volvulus (surgical emergency).
Needs emergent upper GI.
Double bubble with distal gas (3)
Distal gas excludes duodenal atresia.
DDx here is duodenal web, duodenal stenosis or midgut volvulus.
Needs Upper GI.
Multiple diffusely dilated loops DDx (3)
Suggests low obstruction (ileum or colon).
Needs contrast enema. If normal, follow with upper GI to exclude atypical look for midgut volvulus.
Mildly dilated scattered loops DDx (3)
Sick belly
Can be seen with proximal or distal obstruction.
Needs upper GI and contrast enema.
Malrotation (6)
Normally, developmental rotation of the gut places the ligament of Treitz to the left of the spine (level of duodenal bulb).
If this malfunctions, duodenum ends up to the right of the midline.
This causes increased risk of mid gut volvulus, and internal hernias.
Appearance of malrotation and clinical Hx of bilious vomiting is sus for midgut volvulus.
Associated with heterotaxy syndromes and Omphaloceles.
Shown classically as SMA to the right of SMV (on US or CT).
False positive on UGI - Distal bowel obstruction, displacing the duodenum due to ligamentous laxity.
Corkscrew duodenum
Diagnostic of midgut volvulus (surgucal emergency)
Infant with vomiting DDx (2)
Non-bilious: Hypertrophic pyloric stenosis - Next step is US
Bilious: Mid gut volvulus, Next step is Upper GI
Ladd’s bands (3)
In older children or adults, obstruction in a malrotation presents as intermittent episodes of spontaneous duodenal obstruction.
Cause is not midgut volvulus, rather it’s kinking from Ladd’s bands.
These are fibrous stalks of peritoneal tissue that fixes caecum to the abdominal wall, which can obstruct the duodenum.
Ladd’s procedure (5)
To prevent midgut volvulus.
Ladd’s bands are divided and the appendix removed.
Small bowel ends up on the right, large bowel ends up on the left.
These are fixed in place by adhesions, just by opening the abdomen.
Still possible to develop volvulus post Ladd’s, but rare
Complete duodenal obstruction (4)
Strongly associated with midgut volvulus.
Look for distal air to exclude duodenal atresia.
Dilated duodenum (double bubble) will also suggest duodenal atresia.
Partial duodenal obstruction: If vomiting, might be from extrinsic narrowing (Ladd band, annular pancreas) or intrinsic (duodenal web, duodenal stenosis). Can’t tell from fluoro.
Hypertrophic pyloric stenosis (8)
Thickening of gastric pyloric musculature, resulting in progressive obstruction.
“Non bilious vomiting”
Does NOT occur at birth of after 3 months (occurs 2-12 weeks).
Criteria is 4mm single wall thickness, 14mm length.
Primary differential is pylorospasm (will relax during exam).
Commonest pitfall during exam is gastric overdistension, can lead to displacement of antrum and pylorus, leading to false negative.
False positive can occur due to off axis measurements.
“Paradoxical aciduria” is another buzzword
Gastric volvulus (8)
Can be organoaxial or mesenteroaxial.
Organoaxial
- Greater curvature flips over the lesser curvature, rotation along the long axis.
- Seen in old ladies with paraoesophageal hernias.
Mesenteroaxial
- Twisting over the mesentery (rotation along short axis)
- Antrum flips near the OG junction.
- Can cause ischaemia and needs fixed.
- Can cause obstruction
- More common in kids.
Duodenal web (5)
“almost duodenal atresia”
Occurs due to failure to canalize, but instead of total failure, bowel is only partly canalised, leaving behind a potentially obstructive web.
Web is distal to ampulla of Vater, so can get bile stained emesis.
Associated with malrotation and Downs
“Wind sock” deformity is seen in older kids, where web like diaphragm has been stretched.
