Download - Congenital gastrointestinal anomalies
DEVELOPMENTAL ANOMALIES OF GASTROINTESTINAL TRACT
DR. DEV LAKHERA
Classification of developmental anomalies of GIT
STRUCTURAL
EMBRYOLOGICAL MALDEVELOPMENT Malrotation
Oesophageal/ pyloric/ duodenal/ anorectal atresia
Duplication cystIN UTERO (ISCHEMIC) COMPLICATIONS
FUNCTIONAL• Meconium plug syndrome
• -intestinal hypoperistalsis
BOTHMidgut volvulus
AgangliosisHypertrophic pyloric stenosis
Disorders of oesophagus
Oesophageal atresia +/- Tracheo-oesophageal fistula
Congenital oesophageal stenosis, webs and diverticula
Extrinsic compression –foregut duplication cyst
Tracheo-oesophageal fistula
Tracheo-oesophageal septum (5wks)
1 in 5000 births
M:F
VACTERL anomalies
Down’s syndrome
Types
Most common EA with distal
fistula
Chest X-ray
Dilated proximal esophageal pouch with
coiled nasogastric tube within is diagnostic
air in the stomach and the small bowel
ANTENATAL USG
: Oesophageal atresia
• polyhydramnios
• Distended proximal esophageal
pouch
• Small gastric bubble
CONTRAST STUDIES:
Should be avoided, fear of aspiration
• Nonionic isoosmolar contrast medium
• H-type fistulas are mostly at the thoracic inlet, between C7 and T2 vertebral bodies
Congenital stomach disorders
Microgastria Gastric Atresia Antral Mucosal Diaphragm Duplication Cyst Malrotation
Microgastria
Small, tubular, midline stomach
Always associated with anomalies
Failure to thrive
Antral Diaphragm
Mucosal web positioned in the antrum
If large enough, can cause gastric outlet obstruction.
Congenital Hypertrophic Pyloric Stenosis
• 1 in 500, M>>F
• Present between 2-12 wks
• Clinical diagnosis : Mass palpation /Antral peristaltic waves
Ultrasonography is the primary imaging method
On USG
• Thickened hypoechoic pyloric muscle
• Double layer of echogenic mucosa
• Length >16mm
• Thickness >3.5 mm
Transverse section shows the– “Bull’s eye” sign.
Xray and Barium
• ‘STRING SIGN’ - hypertrophied muscle mass causes elongation and narrowing of pyloric canal
• “SHOULDER SIGN” -hypertrophy of the pyloric muscle
Duodenal obstruction (Atresia ,Stenosis, Webs)
Duodenal atresia (1 in 10000)
Most common of all intestinal atresia
25% Downs syndrome
ABDOMINAL RADIOGRAPH:
TYPICAL “DOUBLE-BUBBLE SIGN”
Double bubble on antenatal USG
Duodenal web Incomplete duodenal obstruction
Duodenal web intraluminal diverticulum Windsock sign
MALROTATION
Normal intestinal rotation
Two Processes involved :
Physiological midgut Herniation and Rotation : 6 wks -12 wks
Fixation of mesentery :12 wks -20 wks
6 weeks -physiologic herniation of the midgut through the umbilical orifice (UO).
Superior mesenteric artery (SMA) acts as the axis
prearterial segment
postarterial limb
90-degree counterclockwise rotation Predominant pre-arterial elongation
By 12th week
Fixation
By 3rd to 5th month there is resorption of dorsal mesentery
The base of the normal small bowel mesentery
NONROTATION arrest of the midgut rotation after the first
90 degrees of rotation.
entire colon lies in the left side of abdomen
INCOMPLETE ROTATION AND MALFIXATION
Failure to complete the final 180-degree rotation.
Shortened mesenteric root -allows formation of elongated and mobile segments of colon.
Midgut volvulus.
Classic malrotation Cecum lies left of the midline
Fixed by Ladd bands (aberrant peritoneal bands )
REVERSED INTESTINAL ROTATION –
Transverse colon lie behind the descending duodenum and the superior mesenteric artery
cecum is can be medially placed
Midgut volvulus
Narrow mesentery
Suddenly presents with bilious vomiting
Ischemia and necrosis
Plain radiograph
corkscrew sign
tapering or beaking of the bowel in
complete obstruction
malrotated bowel configuration
Fluoroscopy: contrast study
Ultrasound
clockwise whirlpool sign
abnormal bowel
dilated duodenum proximal to obstruction
dilated fluid-filled loops of small bowel
free intra-abdominal fluid
CT scan
whirlpool sign
malrotated bowel configuration
bowel obstruction
free fluid/free gas in advanced
cases
Meckel’s Diverticulum congenital intestinal diverticulum
omphalomesenteric duct fails to be completely obliterated
Present with obstruction or ulceration
Antimesenteric border
Litters hernia
Xray – non specific
SBFT with a large Meckel diverticulum
99MTC (TECHNETIUM -99M PERTECHNETATE) SCANNING:
ectopic gastric tissue is found in a Meckel's diverticulum
Mid to distal bowel defects
High bowel obstruction – Bilious vomiting
Low bowel obstruction – Failure to pass meconium (< 48 hrs)
Small Bowel Atresia / High intestinal obstruction
Utero-vascular insults
Decreased intestinal perfusion
Ischaemia
Dilated bowel loops proximal to atresia
Triple bubble
PLAIN RADIOGRAPHY
Enema may demonstrate Microcolon
Meconium peritonitis
Bowel perforates as a result of bowel obstruction, such as atresias or meconium ileus
Meconium peritonitis and small bowel obstruction is highly suggestive of atresia.
Low bowel obstruction
Difficult to differentiate on X-ray
Contrast enema is usually required
Water soluble contrast is preferred
Meconium ileus Meconium consists of succus entericus
Cystic fibrosis > 80%
Meconium – viscid distal ileum and colon
Ultrasound appearance
Enteric Duplication Cyst
embryological abnormalities that are lined by intestinal mucosa
distal ileum (35%) > distal esophagus (20%) > stomach (9%) > duodenum > jejunum.
ULTRASONOGRAPHY: Well defined, unilocular anechoic mass
Functional immaturity of colon
Meconium plug syndrome/ small left colon syndrome
Immaturity of bowel innervation
Change in caliber in splenic flexure
Hirschsprung’s Disease
Absence of ganglion cells in bowel wall
Transition point found in the rectosigmoid (73%) > descending colon (14%) > more proximal colon (10%).
Barium enema
Narrowed aganglionic segment
irregular saw-toothed mucosal pattern
Recto-sigmoid ratio <1 abnormal
Delayed radiographs (24 hours) prolonged retention of barium (strong indicator) when enema findings – inconclusive
Confirmatory – rectal biopsy
Colonic Atresia
Distended loops of bowel similar to those seen in low small bowel obstruction.
Anorectal Anomalies
Anal atresia: Vacterl association
range from a membranous separation to complete absence of the anus.
RADIOGRAPH: Invertogram
ULTRASOUND: Delineating distance from the distal pouch to perineum
CYSTOGRAPHY: Delineates associated fistulas between terminal bowel and
urinary tract.
CT & MRI Modalities of choice Help determine presence of puborectalis muscle, external
sphincter and rectal pouch.
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fusiform manner and then with preferential
growth of its dorsal wall
Mesenteric Cyst (Lymphangioma)
congenital malformation arising due to sequestration of lymphatic vessels.
SONOGRAPHY: thin-walled unilocular or multilocular cystic lesion useful to demonstrate the thin septations which may not be well seen on CT.
CT and MRI: demonstrate variable characteristics of the cyst contents (usually water-to fat)
depending upon whether fluid is chylous, infected or haemorrhagic.
Megacystis-microcolon-intestinalHypoperistalsis Syndrome (Berdon Syndrome)
pseudoatresia. functional small bowel obstruction with a microcolon,
malrotation and a large unobstructed bladder
UPPER GI CONTRAST STUDY: hypomotility of small bowel with retrograde peristalsis.
• “DOUBLE TRACT SIGN” – this refers to fluid, trapped in the mucosal folds in the center of an elongated pyloric canal seen as two sonolucent streaks in the center
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