Pediatric High and Low intestinal Obstruction

1. Pediatric High and Low
intestinal Obstruction
DR MUHAMMAD TAHIR JAVED
PGR RADIOLOGY, KEMU/MHL.

2. Low intestinal obstruction
Presents with failure to pass meconium with in first 48 hours of life and multiple
dilated loops seen on abd radiograph due to several pathologies with distal
ileum or colon.
Radiological differentials are :
Meconium ileus
Ileal atresia
Hirschsprung ‘s disease
Functional immaturity of colon
Colonic atresia rarely

3. oIt is difficult to distinguish b/w small and large bowel in
neonate with multiple dilated loops. Then next
investigation is contrast enema.
oSepsis and electrolyte imbalance may cause paralytic ileus
, can be confused but clinical hx is helpful.
oWater soluble contrast is preferred over barium; has
therapeutic benefit in meconium ileus and functional
immaturity. 2nd if perforation has occurred, has less
severe consequences.

4. Aim of study is identify presence or absence of microcolon. Microcolon implies
that insufficient succus entericus has reached colon as result of high grade distal
ileal obstruction.
Such unused colon limits differentials to meconium ileus and ileal atresia.

5. 1-Meconium ileus
 is due to inspissated pellets of abnormally viscid meconium
within the distal ileum and colon.
 Almost all cases are associated with cystic fibrosis.
A mottled bubbly appearance due to meconium mixed with
air may be seen in the right iliac fossa on abdominal
radiograph
There may be greater dilatation of one bowel loop than of the
remainder, which, in this case, represents the terminal ileum
A similar appearance is seen in ileal and colonic atresia, but
the absence of fluid levels on a horizontal beam radiograph
favours meconium ileus.

6. Contrast enema will demonstrate a
microcolon and filling of a dilated terminal
ileum packed with inspissated pellets of
meconium
Non-operative treatment involves the use
of hypertonic enemas to soften the
impacted meconium and induce its
passage.

7. 2- Ileal Atresias
are the result of in utero vascular insults.
Abdominal radiographs demonstrate multiple dilated loops, sometimes with
greater dilatation of one loop but, unlike meconium ileus, multiple fluid levels
are common.
Contrast enema will show an unused microcolon.
 If contrast can be refluxed into the distal ileum it will fill a non-dilated blind-
ending segment with a persistent dilated air-filled loop seen proximally.
Meconium pellets are common but fewer in number than in meconium ileus.
 Treatment is initial ileostomy followed by resection of the atretic segment(s)
and reanastomosis.

8. Ileal atresia.
Contrast enema with microcolon and
reflux into a non-dilated distal ileal
segment with abrupt convex
termination. A few meconium plugs
are present.

9. 3-Hirschsprung’s disease
Due to arrest in the normal cranial-to- caudal neural cell migration, resulting in
absence of ganglion cells within the myenteric plexus of the bowel wall;
70% of cases involve the rectosigmoid region, 25% extend to the splenic flexure
or transverse colon (long segment) and 5% involve the entire colon.
The majority of children present with failure to pass meconium within the first
48 h of life. A smaller number present with intractable constipation
Enterocolitis occurs in 15% of patients and can be the initial presentation, with
fever and diarrhea.
Associations include trisomy 21 and neuroblastoma.

10. While performing a contrast enema for potential Hirschsprung’s disease, it is
important to obtain a lateral rectal view during early filling.
A small catheter (8—10F) is placed just inside the anus.
 The normal neonatal rectum is of greater calibre than the sigmoid colon.
Inversion of the rectosigmoid index, often in association with irregular
contractions of the aganglionic rectum and difficulty in obtaining good rectal
distension is indicative of Hirschsprung’s disease (Fig. 28.24)

11. Hirschsprung's disease.
An abrupt transition zone is seen at the
rectosigmoid junction on this lateral rectal
view from a contrast enema performed on
a 2-day-old boy with failure to pass
meconium. The rectum was difficult to
distend well and showed irregular
contractions.

12. Total colonic Hirschsprung’s disease is difficult to diagnose radiologically.
Findings are subtle but the entire colon tends to be slightly short and rather
featureless, with the hepatic and splenic flexures lying more medially than
normal.
The contrast enema may appear normal in neonatal Hirschsprung’s disease and
the definitive diagnostic investigation remains the rectal biopsy.
Treatment involves defunctioning colostomy followed by surgical repair.

13. 4-Functional immaturity of the colon
 AKA the small left colon syndrome, meconium plug syndrome and functional
colonic obstruction.
 It is believed to be due to a relative immaturity of bowel innervation and
motility in full-term infants.
There is an increased incidence in infants of diabetic mothers.

14. Contrast enema shows a dilated ascending and transverse colon with a change
in calibre at the splenic flexure and a small left, descending colon.
A large mucous plug may be present in the splenic flexure, but this is not
invariable.
 The rectosigmoid index/ratio is normal.
The condition is usually self-limiting, with the contrast enema acting as a
stimulus for subsequent passage of meconium and gradual improvement in
clinical symptoms
A degree of functional immaturity of the bowel is often observed in premature
infants. Contrast enema can occasionally be helpful as a therapeutic maneuver.

15. Functional immaturity (left colon
syndrome).
Contrast enema in a newborn term infant
showing a relatively small left colon,
transition zone at the splenic flexure and a
large coiled meconium plug which was
dislodged from the splenic flexure to the
hepatic flexure during colonic filling.

16. 5- Colonic Atresia
They are rare and have vascular aetiology.
The abdominal radiograph demonstrates low intestinal obstruction, sometimes
with a very dilated proximal colon.
Contrast enema demonstrates a blind-ending colon with a convex distal border
at the atretic site.

17. Colonic atresia.
AXR (A) showing disproportionate
dilatation of one bowel loop in a
neonate with abdominal
distension and failure to pass
meconium.
Contrast enema (B) showing a
blind-ending colon with a convex
distal border in the splenic flexure.
The dilated air-filled proximal
colonic segment can be seen

18. High intestinal obstruction
Atresia or stenoses of jejunum or proximal ileum
Duodenal atresia/stenosis
Inguinal hernia
Necrotizing enterocolitis
Duplication cysts

19. Atresia or stenoses of jejunum or
proximal ileum
•Usually presents with bilious vomiting with small number of dilated bowel loops
•Gives tipple bubble sign on abdominal radiograph
•Usually no further imaging required prior to surgery but if requested, a contrast
follow through is done to localize site of obstruction
•Results by in utero vascular insults
•Complete atresia re more common than stenoses and may be single or multiple

20. Colonic appearances depends upon GI timing of ischemic injury and level of
obstruction.
Colon caliber is mildly reduced or normal, in late high jejunal atresia as
sufficient succus entericus is produced to stimulate near normal colonic caliber.
Presence of micro colon is suspicious of Earlier , more distal ileal atresia

21. Jejunal atresia
Supine (AP) view of abdominal radiograph
demonstrates the “triple bubble sign” with
dilated stomach (bold arrow),
duodenum (arrowhead),
and proximal jejunum (curved arrow).
A NG tube is also identifed which is used for
gastric decompression.

22. 4daysmale withhxof Vomitingfeeds.Initiallypassedmeconium,butfailuretopassnormalamounts.Worseningabdominaldistension.
AXR: Marked gaseous distension
of proximal small bowel loops
with an abrupt cut-off to the left
of midline.
Nasogastric tube in situ
Scout image of fluoroscopic study:
Contrast fills distended bowel with
abrupt cut-off in the region of the
distal duodenum/proximal jejunum.
Barium enema:
Contrast per-rectum confirms a
microcolon which is seen in disuse,
e.g. where there is small bowel
atresia.

23. Necrotizing Enterocolitis
A severe inflammatory enteritis affecting preterm infants, under 2000grams.
Common Pathway appears to be via bowel ischemia, proliferation of intestinal
flora leading to bowel necrosis and perforation.
Distal ileum and ascending are mostly affected.
S/S include Abd distension, vomiting, diarrhea, blood per rectum, metabolic
acidosis and circulatory collapse.

24. In early stages , abd radiograph are often non specific, may show generalized
bowel distension.
Bowel wall thickening and pneumatosis may then develop.
Bubbly round lucencies are due to submucosal air.
Linear lucencies are due to subserosal air.
Portal venous air may be seen on radiograph or USG.
A persistent dilated loop with no interval change on serial films is suspicious for
bowel ischemia may proceed to perforation.

25. Free air can be detected on supine radiograph by
the foot ball sign , visualization of falciform
ligament or Rigler sign.
Free Intraperitoneal air in perforated necrotising
enterocolitis demonstrated by lucency over the
entire abdomen (football sign), subdiaphragmatic
air and outlining of both sides of the bowel wall
(Rigler's sign).

26. Lateral films are more sensitive in detection of small
triangles of free air between bowel loops below
anterior abdominal wall.
Necrotizing enterocolitis.
Supine AXR (A) demonstrating extensive 'bubbly'
pneumatosis in a 16-day-old premature infant born at
28 weeks gestation. No definite free air seen.
However, lateral shoot-through radiograph (B) shows a
small triangle of free air beneath the anterior
abdominal wall (arrow). A localised ileal perforation
was found at laparotomy.

27. Contrast enhanced studies are not indicated due to risk of perforation.
Post NEC strictures are commonly in the splenic flexures.

28. Duplication cysts
May occur anywhere along GI tract but 1/3 of cases involve the distal small
bowel.
Due to incomplete recanalisation at around 8 weeks gestation, they may be
spherical or tubular and are lined with gastrointestinal epithelium.
The most frequent sites of duplication are the ileum, then oesophagus,
stomach, duodenum and jejunum.
Large cysts may present with abdominal pain, obstruction and vomiting.
Abdominal radiographs may show mass effect with displacement of adjacent
bowel loops.

29. Ultrasound demonstrates a simple hypoechoic
cyst;
if the characteristic 'gut-wall signature' of an
inner echogenic mucosa and outer hypoechoic
smooth muscle layer can be identified, the
diagnosis can be made)
Duplication cyst.
Hypoechoic cyst with double 'gut wall signature'. In this case the
adjacent segment of bowel can be seen along the superior border
of the cyst, confirming its origin