The invagination of a part of the intestine into
itself. It is the most common abdominal
emergency in early childhood
Is the most common cause of
intestinal obstruction in infants
between 6 and 36 mo of age. 60 % of
children are younger than one year
old, and 80 % are younger than two.
Intussusception is less common
before 3mo and after 6yr of age.
Most episodes occur in otherwise
healthy and well-nourished children.
male:female ratio of 3:2.
Occurs most often near the ileocecal
junction (ileocolic intussusception).
Ileo-ileo-colic, jejuno-jejunal, jejuno-ileal,
or colo-colic. The intussusceptum, a
proximal segment of bowel, telescopes
into the intussuscipiens, a distal
segment, dragging the associated
mesentery with it. This leads to the
development of venous and lymphatic
congestion with resulting intestinal
edema, which lead to ischemia,
perforation, and peritonitis.
Approximately 75 % of cases are
idiopathic because there is no clear
disease trigger or pathological lead
point most common in children
between 3mo and 5yr of age.
Influence of viral factors
illustrated by the following observations:
Has a seasonal variation, with peaks coinciding
with seasonal viral gastroenteritis.
Associated with some forms of rotavirus vaccine.
30 % experience viral illness (URTI, otitis media,
flu-like symptoms) before the onset of
A strong association with adenovirus infection .
Viral infections, including enteric adenovirus, can
stimulate lymphatic tissue in the intestinal tract,
resulting in hypertrophy of Peyer patches in the
lymphoid-rich terminal ileum, which may act as a
lead point for ileocolic intussusception .
treatment with glucocorticoids has been
suggested to prevent recurrence.
Other enteric infections
Bacterial enteritis (Salmonella, E.
Coli, Shigella, or Campylobacter).
Most cases of intussusception
occurred within the first month after
the bacterial enteritis.
A lead point is a lesion or variation in
the intestine that is trapped by
peristalsis and dragged into a distal
segment of the intestine, causing
A Meckel diverticulum, polyp,
tumor, hematoma, or vascular
malformation can act as a lead
point for intussusception.
25 % of cases( a pathological lead point),
which may be focal or diffuse. Such triggers
greater in children younger than 3MO or older
Meckel diverticulum, polyps, small
bowel lymphoma, duplication cysts,
vascular malformations, inverted
appendiceal stumps, parasites (eg,
Ascaris lumbricoides), Henoch-Schönlein
purpura, cystic fibrosis, and hemolyticuremic syndrome. Meckel diverticulum is
the most common, followed by polyps,
and then either duplication cysts or
The mechanisms leading to intussusception :
Meckel diverticulum, polyps, duplication cysts,
lymphomas, areas of reactive lymphoid
hyperplasia, or other focal abnormalities of the
intestinal tract act as lead points, dragging the
intestine into a distal segment of intestine.
With Henoch-Schönlein purpura, a small bowel
wall hematoma acts as the lead point.
Intussusception typically occurs after resolution of
the abdominal pain.
cystic fibrosis( thick inspissated stool may act as
the lead point).
celiac disease ( dysmotility and excessive
secretions or bowel wall weakness).
Patients with Crohn disease ( inflammation and
Postoperative — (usually jejuno-jejunal or ileoileal) is thought to be caused by uncoordinated
peristaltic activity and/or traction from sutures or
devices. Affected patients typically do well for
several days and may even resume oral intake
before developing symptoms of mechanical
The diagnosis can be difficult to establish
because intussusception may be confused with
postoperative paralytic ileus. Evaluation with
ultrasonography or (CT) scanning can establish
the diagnosis, monitor for spontaneous reduction,
and help to predict which children are likely to
need surgical reduction. Because most cases of
postoperative intussusception occur in the small
intestine, contrast enemas do not usually
contribute to the diagnosis.
sudden onset of intermittent, severe, crampy, progressive
abdominal pain, accompanied by inconsolable crying and
drawing up of the legs toward the abdomen. The episodes
usually occur at 15 to 20 min intervals. They become more
frequent and more severe over time. Vomiting may follow
episodes of abdominal pain. Initially, emesis is non-bilious,
but it may become bilious as the obstruction progresses.
Between the painful episodes, the child may behave
relatively normal and be free of pain. As a result, initial
symptoms can be confused with gastroenteritis. As symptoms
progress, increasing lethargy develops, which can be
mistaken for meningoencephalitis.
A sausage-shaped abdominal mass may be felt in the right
side of the abdomen. In up to 70 %of cases, the stool
contains gross or occult blood. The stool may be a mixture of
blood and mucous, giving it the appearance of currant jelly.
classically ( pain, a palpable sausage-shaped mass, and
currant-jelly stool) is seen in less than 15 % of patients at the
time of presentation.
20 % of young infants have no obvious pain.
1/3 of patients do not pass blood or mucus, nor do they
develop an abdominal mass.
Many older children have pain alone without other signs or
Occasionally, the initial presenting sign is lethargy or
altered consciousness alone, without pain, rectal bleeding, or
other symptoms that suggest an intraabdominal process. This
clinical presentation primarily occurs in infants and is often
confused with sepsis. Thus, intussusception should be
considered in the evaluation of otherwise unexplained
lethargy or altered consciousness, especially in infants.
An intussusception is sometimes discovered incidentally
during an imaging study performed for other reasons or for
nonspecific symptoms. If these intussusceptions are short
and if the patient has few symptoms, they may not require
Depends on the clinical suspicion for intussusception
(typical or atypical presentation) and experience
Patients with a typical presentation (sudden onset of
intermittent severe abdominal pain with or without rectal
bleeding) or characteristic findings on radiography, may
proceed directly to nonoperative reduction using
hydrostatic (contrast or saline) or pneumatic (air)
enema, performed under either sonographic or
fluoroscopic guidance. In these cases, the procedure is
both diagnostic and therapeutic.
If diagnosis is unclear at presentation. In this case,
initial workup may include abdominal ultrasound or
abdominal plain films. If the study supports the
diagnosis of intussusception, nonoperative reduction is
Is the method of choice to detect
intussusception. The sensitivity and
specificity approach 100 % in the hands of an
experienced. US is better than fluoroscopic in
detect pathological lead points , monitor the
success of a reduction , not expose the
patient to radiation
The classic ultrasound image is a "bull's eye"
or "coiled spring" lesion representing layers
of the intestine within the intestine (picture 2).
In addition, a lack of perfusion in the
intussusceptum detected with color duplex
imaging may indicate ischemia. US can
diagnose the rare ileo-ileal intussusception
and identify the lead point of intussusception
2/3of cases .
US features for small bowel
intussusception include location of the
intussusception in the paraumbilical or
left abdominal region and/or lesion size
≤3 cm; in such cases, evaluation with a
CT scan may help to confirm the location
of the intussusception and whether there
is a lead point. In small bowel
intussusceptions, the length of the
intussusceptum, as measured by
ultrasound or CT, helps determine
prognosis and management.
Abdominal plain film
Plain radiographs of the abdomen are
less sensitive and less specific than
ultrasonography for the diagnosis of
intussusception, but are often
performed as part of the evaluation of
patients with abdominal symptoms.
Radiographic features include signs of
intestinal obstruction, massively
distended loops of bowel with absence
of colonic gas (picture 3).
Other findings may be seen:
A target sign, consisting of two concentric radiolucent circles
superimposed on the right kidney, represents peritoneal fat
surrounding and within the intussusception. This finding
appeared in 26 % of patients.
A soft tissue density projecting into the gas of the large bowel
(representing the intussusception) is called the "crescent
An obscured liver margin
Lack of air in the cecum, which prevents its visualization
pneumoperitoneum suggests that bowel perforation has
The presence of air in the cecum on at least two views had
high sensitivity for excluding intussusception with a low
clinical suspicion .
more than 20 % of patients with intussusception had negative
However, CT cannot be used to
reduce the intussusception and can be
time-consuming in children who may
require sedation. Thus, CT generally
is reserved for patients in whom the
other imaging modalities are
unrevealing, or to characterize
pathological lead points for
intussusception detected by
Stable patients with a high clinical suspicion
and/or radiographic evidence of
intussusception and no evidence of bowel
perforation should be treated with
Surgical treatment is indicated in acutely ill
or perforation. radiographic facilities and
expertise to perform nonoperative reduction
are not available. nonoperative reduction is
unsuccessful, or for evaluation or resection of
a pathological lead point.
intussusception limited to the small bowel
(ileo-ileal, jejuno-ileal, or jejuno-jejunal).
using hydrostatic or pneumatic pressure by enema has
high success rates in children with ileocolic
intussusception, and is the treatment of choice for a
stable child and radiologic facilities are available.
contridication ;long duration of symptoms and/or
suspected bowel perforation.
Patient should be stabilized and resuscitated with IVF,
and the stomach decompressed with a nasogastric
tube. Because there is a risk of perforation during
nonoperative reduction, the surgical team should be
notified and steps should be taken to ensure that the
patient is fit for surgery.
Antibiotics administered before attempting nonoperative
reduction because of the risk of perforation.
After successful reduction, a temperature
higher than 38ºC because of bacterial
translocation or the release of endotoxin or
cytokines. risk to develop recurrent
intussusception in the near term, possibly
because of residual bowel inflammation,
which may itself act as a lead point. Patient
should be observed in the hospital for 12 to
24 hours. Nasogastric suction usually is
maintained until bowel function has returned
and the patient has had passage of a bowel
movement. Feedings then are advanced as
Fluoroscopic or sonographic
Reduction is typically performed under
fluoroscopic guidance, using either
hydrostatic (contrast) or pneumatic
(air) enema. Has high success rates
(80 to 95 %) and is an appropriate
choice if the treating physicians have
more experience with this technique
than with ultrasound-guided reduction.
Successful reduction ;
1. free flow of contrast or air into the small bowel. Reduction is
complete only when a good portion of the distal ileum is filled
2. Relief of symptoms and disappearance of the abdominal
mass. A characteristic sound also may be appreciated with
3. In occasional patients, the contrast material does not reflux
freely into the small bowel even with a complete reduction,
however a successful reduction is suggested by lack of a
filling defect in the cecum (apart from the ileocecal valve),
and clinical resolution of symptoms and signs.
A post-reduction filling defect in the cecum commonly is seen,
probably the result of residual edema in the ileocecal valve.
However, this finding cannot be distinguished from a focal
lead point by radiologic examination alone. As a result, a
repeat study or even laparotomy may be indicated if there is
any concern of a focal lead point.
Barium a water-soluble contrast enema is preferred
because of the risk of perforation before or during the
procedure. reduce the risk of electrolyte disturbances
and peritonitis in patients in whom perforation has
sonographic guidance, and is now the intervention of
choice for ileocolic intussusception in many institutions.
air or saline enemas. Signs of successful reduction
with saline include the disappearance of the
intussusception and the appearance of water and
bubbles in the terminal ileum.
Ultrasound-guided have a success rate of 80 to 95 %
for most types of intussusception, which is comparable
to those of fluoroscopic techniques. The main
advantage of ultrasound-guided reduction is avoidance
of radiation exposure and improved detection of
pathological lead points as compared to fluoroscopic
Hydrostatic technique — The standard
method of reduction is to place a
reservoir of contrast 1 meter above the
patient so that constant hydrostatic
pressure is generated. With experience
(and depending upon the clinical status
of the patient), a physician may
undertake a more aggressive reduction.
When hydrostatic reduction is
performed under ultrasonographic
guidance, normal saline is used for the
Pneumatic technique — Air reduction
techniques have gained popularity as
an alternative to the hydrostatic
methods, and can be used under
either ultrasonographic or fluoroscopic
guidance (picture 5). Air enemas
reduce the intussusception more
easily, and may be advantageous if
The technique begins with insertion of a Foley catheter
into the rectum. Fluoroscopy or ultrasound is used to
monitor the procedure. Air is then instilled until the
intussusceptum is pushed back gently, taking care to
avoid excessive pressure.
sphygmomanometer can be used to monitor colonic
intraluminal pressure (typically not to exceed 120 mm
Hg) to aid in reduction. Carbon dioxide can also be
used instead of air. It has the advantage of being
absorbed rapidly from the gut, is associated with less
discomfort, and is less dangerous than air, which
potentially could cause an air embolism (although air
embolisms have not been reported).
Reflux of air into the terminal ileum and the
disappearance of the mass at the ileocecal valve
usually indicates reduction (picture 6A-B). If fluoroscopy
is used, water-soluble contrast material can be instilled
to confirm the reduction, or the air reduction can be
repeated if the completeness of reduction is questioned.
Risk and complications
perforation of the bowel 1 %. on distal side of the
intussusception, often in the transverse colon, and commonly
where the intussusception was first demonstrated by
Risk factors ; age younger than 6mo.
long duration of symptoms (eg, 3 days or longer).
evidence of small bowel obstruction.
use of higher pressures during the reduction.
Should not be attempted in prolonged symptoms or any signs
of peritoneal irritation or free peritoneal air.
The pneumatic reduction provides an advantage if perforation
occurs, because air is generally less harmful. When
perforation is noted with air reduction, the colonic wall tears
are smaller than those observed with the hydrostatic contrast
techniques, and peritoneal pathology tends to be minimal.
Needle decompression of the abdomen may be necessary if
the excess air in the peritoneal cavity compromises the
patient's respiratory status.