Intestinal atresia

Presented by
Dr. PANKAJ YADAV
drpankajyadav05@gmail.com
Intestinal Atresia

 Questions
 1. incidence of intestinal atresia in down
 2. Paradoxical aciduria in pyloric stenosis
 3. VACTERAL
 4. omphalocele and related
 5. what age duodenal atresia be treated
 6. incidence of intestinal atresia

 Intestinal obstruction occurs in ≈1/1,500 live births
Two types
 Simple -Simple obstruction is associated with the
failure of progression of abnormal flow of luminal
contents.
 Strangulating-Strangulating obstruction is
associated with impaired blood flow to the intestine
in addition to obstruction of the flow of luminal
contents. it can lead to bowel infarction and
perforation.

Pathophysiology
 Accumulation of ingested food, gas, and intestinal
secretions proximal to the point of obstruction,
leading to distention of the bowel.
 As the bowel dilates, intestinal absorption decreases
and secretion of fluid and electrolytes increases. i.e.
isotonic intravascular depletion usually associated
with hypokalemia.
 Gut proximal to the obstruction initially demonstrates
an increase in contractile activity, which is followed
by a marked decrease with hypoactive bowel
sounds.

 The combination of fluid accumulation (distention)
and hypomotility is associated with nausea and
vomiting.
 Blood flow to the obstructed bowel decreases as the
bowel dilates.
 Blood flow is shifted away from the mucosa, with
loss of mucosal integrity.
 Bacteria proliferate in the stagnant bowel, with a
predominance of coliforms and anaerobes.
 Bacterial translocation across the bowel wall,
potentially resulting in endotoxemia, bacteremia, and
sepsis.

Congenital obstructive lesions of
the intestines
 Intrinsic
 atresia,
 stenosis,
 meconium ileus,
 aganglionic megacolon.
 extrinsic
 malrotation,
 constricting bands,
 intra-abdominal hernias,
 duplications.

 Atresia - complete obstruction of the bowel
lumen
 stenosis - partial block of luminal contents
 Intestinal atresia is common in the duodenum,
jejunum, and ileum and rare in the colon.
 Intestinal atresia accounts for ≈33% of all cases
of neonatal intestinal obstruction
 affects males and females with equal frequency.
 Intestinal atresia impairs the development of the
myenteric plexus below the level of atresia,

Clinical presentation
 Depends on
 cause,
 level of obstruction, and
 time between the obstructing event and the patient's
evaluation.

High intestinal obstruction
 Polyhydramnios accompanies high intestinal
obstruction.
 Aspiration of 15–20 mL or more of gastric fluid,
especially if it is bile stained, is suggestive of a
high intestinal obstruction
 Meconium stools can be passed initially if the
obstruction is in the upper part of the small
intestine or if the obstruction developed late in
intrauterine life

 The classic symptoms of obstruction include nausea
and vomiting, abdominal distention, and obstipation.
 Obstruction high in the intestinal tract involving the
duodenum or proximal jejunum results in large-
volume, frequent, bilious emesis.
 Pain is intermittent and is usually relieved by
vomiting.
 The pain is localized to the epigastrium or
periumbilical area, and there is little abdominal
distention.
 hypochloremic metabolic alkalosis

Distal small bowel obstruction
 moderate or marked abdominal distention with
emesis that is progressively feculent.
 Pain is usually diffuse over the entire abdomen.

Incomplete obstructions
 as with intestinal stenosis,
 constricting bands,
 duplications
 incomplete volvulus),
 signs may appear shortly after birth or may be
delayed an indeterminate time.

Investigations
 ABG - Hypochloremic metabolic alkalosis
 TLC - Marked leukocytosis with or without
thrombocytopenia
 Stool Routine - Hematochezia in a patient with
obstruction suggests bowel infarction.
 Serum amylase and lipase - determinations
should be performed to rule out pancreatitis.

 Bowel obstruction is usually suggested on the
basis of history (including prenatal
ultrasonography) and physical examination
 Imaging is used to confirm the diagnosis and
localize the area of obstruction.
 Plain supine and erect or decubitus radiographs
are the initial studies.

X- ray abdomen
 upright or cross-table lateral position
 distention of the bowel is noted above the
obstruction and a series of fluid levels with
superimposed gas in the distended loops
 Pneumoperitoneum –
 if there is a perforation with free air in the
subphrenic regions or over the liver in the left lateral
decubitus position

X- ray abdomen
 Calcification within the peritoneal cavity
 indicates meconium peritonitis.
 meconium ileus
 characteristic ground-glass appearance in the right
lower quadrant with trapped bubbles of air within
the obstructing meconium may be seen in patients
with meconium ileus.

X- ray abdomen
 Air is usually demonstrable radiographically in the
stomach of a normal infant immediately after
birth;
 within 1 hr, air may reach the proximal portion of
the small intestine and segments of the colon;
 air may become visible in the distal parts of the
colon as early as the 3rd hr or as late as 18 hr.

Ultrasonography
 Ultrasonography
 identifying pyloric stenosis,
 malrotation, and
 volvulus or intussusception
 CT scan
 sensitive and specific for diagnosing small bowel
obstruction, especially in children >2 yr.

 Water-soluble contrast enemas are useful in
diagnosing malrotation, meconium ileus, meconium
plug, and intussusception.
 In meconium ileus, meconium plug, and
intussusception, the enema may be diagnostic and
relieve the obstruction.
 Oral or nasogastric contrast medium is used to
identify obstructing lesions in the proximal bowel
(atresia, volvulus, malrotation).
 Water-soluble agents are used if perforation is
suspected.

MANAGEMENT
 Initial treatment –
 fluid resuscitation and stabilizing the patient.
 Nasogastric decompression
 usually provides relief of pain and vomiting
 broad-spectrum antibiotics
 are usually started in ill-appearing neonates with
bowel obstruction and those with suspected
strangulating infarction.

 Surgery
 Patients with strangulation must have immediate
surgical relief before the bowel infarcts, resulting in
gangren and intestinal perforation.
 Nonoperative conservative management
 limited to children with suspected adhesions or
inflammatory strictures that may resolve with
nasogastric decompression or anti-inflammatory
medications.
 If clinical signs of improvement are not evident within
12–24 hr, then operative intervention is usually
indicated.

Duodenal atresia
 Due to failure to recanalize the lumen after the
solid phase of intestinal development in the 4th
and 5th wk of gestation.
 The incidence of duodenal atresia is 1/10,000
births
 Accounts for 25–40% of all intestinal atresias.
 Half the patients are born prematurely.
 Down syndrome occurs in 20–30% of patients
with duodenal atresia.
 Other congenital anomalies that are associated
with duodenal atresia include malrotation (20%),
esophageal atresia (10–20%), congenital heart
disease (10–15%), and anorectal and renal
anomalies (5%).

 Types
 intact membrane obstructing the lumen,
 a short fibrous cord connecting two blind duodenal
pouches, or
 a gap between the nonconnecting ends of the
duodenum.
 An unusual cause of obstruction is a ―windsock‖ web,
which is a distensible flap of tissue associated with
anomalies of the biliary tract.
 membranous form of atresia is most common, with
obstruction occurring distal to the ampulla of Vater in
the majority of patients.
 Duodenal obstruction can also be a result of an
extrinsic compression such as an annular pancreas
or from Ladd bands in patients with malrotation.

CLINICAL MANIFESTATIONS
 The hallmark is bilious vomiting without abdominal
distention, which is usually noted on the 1st day of
life.
 Peristaltic waves may be visualized early in the
disease process.
 A history of polyhydramnios is present in half the
pregnancies and is caused by a failure of absorption
of amniotic fluid in the distal intestine.
 Jaundice is present in one third of the infants.

 The diagnosis is suggested by the presence of a
―double-bubble sign‖ on plain abdominal
radiographs.
 The appearance is caused by a distended and gas-
filled stomach and proximal duodenum.
 Contrast studies may occasionally be needed to
exclude malrotation and volvulus because intestinal
infarction may occur within 6–12 hr if the volvulus is
not relieved.
 Prenatal diagnosis of duodenal atresia is readily
made by fetal ultrasonography

TREATMENT
 Initial - Nasogastric or Orogastric decompression
and intravenous fluid replacement.
 Echocardiogram and radiology of the chest and
spine should be performed to evaluate for
associated anomalies.
 Definitive correction of the atresia is usually
postponed to evaluate and treat these life-
threatening anomalies.

 Surgery
 duodenoduodenostomy.
 The dilated proximal bowel can be tapered in an
attempt to improve peristalsis.
 A gastrostomy tube can be placed to drain the
stomach and protect the airway.
 Intravenous nutritional support or a transanastomotic
jejunal tube is needed until infants start to feed
orally.

 If obstruction is due to Ladd bands with malrotation,
an operation is necessary without delay.
 After division of the abnormal peritoneal folds or
bands, the entire large intestine is placed within the
left side of the abdomen, after 1st removing the
appendix, with the small bowel on the right—the fetal
position of nonrotation.
 Appendectomy is performed to avoid later
misdiagnosis of appendicitis.

 Malrotation can also coexist with an intrinsic
duodenal obstruction, such as a membrane or
stenosis;passing a balloon-tipped catheter into the
jejunum below the site of obstruction, inflating the
balloon, and slowly withdrawing the catheter may
identify this.
 Annular pancreas is best treated by
duodenoduodenostomy without dividing the
pancreas, leaving as short a defunctioned loop as
possible.
 Duodenal diaphragmatic obstruction is managed
by duodenoplasty

Jejunal and Ileal Atresia and
Obstruction
 Jejunoileal atresia have been attributed to
intrauterine vascular accidents leading to ischemic
necrosis of the sterile bowel and resorption of the
affected segments.
 Polyhydramnios occurs in 25% of affected patients
 Monozygotic twins are at higher risk
 Premature birth occurs in 30% of infants.
 Atresia has also been associated with low
birthweight, multiple births, and maternal cocaine
use and cigarette smoking.

 Type I
 accounts for 20% of the atresias and is an
intraluminal diaphragm that obstructs the lumen
while continuity is maintained between the proximal
and distal bowel
 Type II
 a small-diameter solid cord connects the proximal
and distal bowel, accounting for about 35% of
defects

 Type III is divided into two subtypes.
 Type IIIa
 accounts for ≈35% of all atresias
 both ends of the bowel end in blind loops accompanied
by a small mesenteric defect.
 Type IIIb
 extensive mesenteric defect
 loss of the normal blood supply to the distal bowel.
 The distal ileum coils around the ileocolic artery, from
which it derives its entire blood supply, producing an
―apple-peel‖ appearance. This anomaly is associated
with prematurity, an unusually short distal ileum, and
significant foreshortening of the bowel

 Type IV
 multiple segments of bowel atresia
 accounts for ≈5% of all bowel atresias.

Meconium ileus
 Approximately 10% of infants with cystic fibrosis develop
meconium ileus;
 80–90% of infants presenting with meconium ileus have
cystic fibrosis.
 simple meconium ileus
 the last 20–30 cm of ileum is collapsed and filled with pellets
of pale-colored stool, above which a dilated loop of varying
length appears obstructed by meconium of the consistency
of thick syrup or glue.
 complicated meconium ileus
 Accompained by Volvulus, atresia, or perforation of the
bowel
 Perforation in utero produces meconium peritonitis.
Intraperitoneal meconium can cause dense adhesions,
leading postnatally to adhesive intestinal obstruction, anddrpankajyadav05@gmail.com

CLINICAL MANIFESTATION
 Most symptomatic in the 1st day of life with
abdominal distention and bile-stained emesis or
gastric aspirate.
 60 to 75% of the infants fail to pass meconium.
 Jaundice has been found in 20–30% of the patients.
 Plain radiographs demonstrate many air-fluid levels
or peritoneal calcification associated with meconium
peritonitis.
 Contrast studies of the upper and lower bowel can
delineate the level of obstruction and differentiate
atresia from meconium ileus, meconium plug, and
Hirschsprung disease.drpankajyadav05@gmail.com

 In meconium ileus-
 typical hazy or ground-glass appearance in the right
lower quadrant. Small bubbles of gas trapped in
meconium are dispersed within this area.
 Because of their viscid contents, moderately dilated
loops of bowel do not have the air-fluid levels usually
seen radiographically on the erect projection.
 If there is meconium peritonitis, patchy calcification
may be noted, usually in the flanks.
 Pneumoperitoneum - as free air between the liver
and the diaphragm on an upright radiograph of the
abdomen; if there is a large amount of free air, the
entire abdomen may look like a football from
distention with air; the ligamentum teres is
sometimes clearly visible in the midline.

TREATMENT
 Initial -fluid and electrolyte balance
 Prophylactic antibiotics
 Ileal or jejunal atresia
 resection of the dilated proximal portion of the
bowel followed by end-to-end anastomosis.
 In uncomplicated meconium ileus,
 Gastrografin enemas will diagnose the obstruction
and wash out the inspissated material. Gastrografin
is hypertonic and care must be taken to avoid
dehydration, shock, and bowel perforation, may
have to be repeated after 8–12 hr

 50% of patients with simple meconium ileus do not
adequately respond to water-soluble enemas and
need laparotomy.
 Operative management is indicated when the
obstruction cannot be relieved by repeated attempts
at nonoperative management and for infants with
complicated meconium ileus.
 In simple meconium ileus, the plug can be relieved
by manipulation or direct enteral irrigation with N-
acetylcysteine following an enterotomy.
 In complicated cases, bowel resection, peritoneal
lavage, abdominal drainage, and stoma formation
may be necessary.
 Total parenteral nutrition will be required.

Intestinal atresia

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