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.

THANK YOU

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

THANK YOU