TOPIC PRESENTATION

INTUSSUSCEPTION

Introduction

Intussusception is a process in which a segment of intestine invaginates into the adjoining intestinal lumen,
causing bowel obstruction. (Intussusception is the result of invagination or telescoping of a portion of bowel into
the more distant bowel – Oski’s). It is the most common cause of intestinal obstruction in infants from 3 months
to 3 years of age. It is rare in the 1st month of life and a peak occurrence between 5 – 9 months of age.

Intussusception presents in 2 variants: idiopathic intussusception, which usually starts at the ileocolic
junction and affects infants and toddlers, and enteroenteral intussusception (jejunojejunal, jejunoileal,
ileoileal), which occurs in older children. The latter is associated with special medical situations (eg, Henoch-
Schönlein purpura [HSP], cystic fibrosis, hematologic dyscrasias) and can occur secondary to a lead point( eg
polyps, Merkel diverticulum, nodular or ectopic pancreas, lymphomas and benign tumors of ileal wall) and
occasionally in the postoperative period. This discussion concentrates on idiopathic intussusception, which is
the more common of the 2 variants.

Abdominal radiograph shows small bowel dilatation and paucity of gas in the right lower
and upper quadrants.
Air contrast enema shows intussusception in the cecum.

Barium enema shows intussusception in the descending colon.

CT scan reveals the classic ying-yang sign of an intussusceptum inside an intussuscipiens.

Abdominal ultrasonography reveals the classic target sign of an intussusceptum inside an

intussuscipiens.

Laparoscopic view of a jejuno-jejunal intussusception

Pathophysiology
The pathogenesis of intussusception is believed to be secondary to an imbalance in the longitudinal forces
along the intestinal wall. This imbalance can be caused by a mass acting as a lead point or by a disorganized
pattern of peristalsis (eg, an ileus in the postoperative period). Electrolyte derangements associated with
various medical problems can produce aberrant intestinal motility, leading to its invagination.

As a result of the imbalance, an area of the intestinal wall invaginates into the lumen, with the rest of the
intestine following. The invaginating portion of the intestine (ie, intussusceptum) completely invaginates into
the receiving portion of the intestine (ie, intussuscipiens). This process continues and more proximal areas
follow, allowing the intussusceptum to proceed along the lumen of the intussuscipiens.

If the mesentery of the intussusceptum is lax and the progression is rapid, the intussusceptum can proceed to
the distal colon or sigmoid and even prolapse out the anus. The mesentery of the intussusceptum is
invaginated with the intestine, leading to the classic pathophysiologic process of any bowel obstruction.

Early in this process, lymphatic return is impeded; then, with the rise in the pressure within the wall of the
intussusceptum, venous drainage is impaired. Finally, the pressure reaches a point at which arterial inflow is
inhibited, and ischaemia and infarction ensues. The mucosa is most sensitive to ischemia because it is farthest
away from the arterial supply. Ischemic mucosa sloughs off and venous engorgement results in leakage of
blood into the intestinal lumen, which initially leads to the heme-positive stools and then the classic "currant
jelly stool" (a mixture of sloughed mucosa, blood, and mucus). If untreated, the process progresses to
transmural gangrene and perforation of the leading edge of the intussusceptum.

Frequency
Its estimated incidence in US is approximately 1 case per 2000 live births.

Mortality/Morbidity
With early diagnosis, appropriate fluid resuscitation, and therapy, the mortality rate from intussusception in
children is less than 1%. The morbidity rate is very low after treatment of intussusception.

Race
No significant difference in the incidence of intussusception is reported between races.

Sex
Most series report a slight preponderance of males, with a male-to-female ratio of approximately 3:2.

Age
Two thirds of children with intussusception are younger than 1 year; most commonly, intussusception occurs in
infants aged 5-9 months. Although extremely rare, intussusception has been reported in the neonatal period.
Intussusception can account for as many as 25% of abdominal surgical emergencies in children younger than 5
years, exceeding the incidence of appendicitis.

From a clinical perspective, using a cutoff age of 3 years is helpful for dividing patients with intussusception into
2 groups. Patients aged 5 months to 3 years who have intussusception rarely have a lead point (ie, idiopathic
intussusception) and are usually responsive to nonoperative reduction. Older children and adults more often
have a surgical lead point to the intussusception and require operative reduction.
Clinical

History
The classic triad of vomiting, abdominal pain, and passage of blood per rectum occurs in only one third of
patients. The patient is usually an infant who presents with vomiting, abdominal pain, passage of blood and
mucus, lethargy, and a palpable abdominal mass. These symptoms are often preceded by an upper respiratory
infection.

Symptoms include the following:

• Pain is colicky, severe, and intermittent. The parents or caregivers describe the child as drawing the
legs up to the abdomen and kicking the legs in the air. In between attacks, the child appears calm and
relieved.
• Initially, vomiting is nonbilious and reflexive, but when the intestinal obstruction occurs, vomiting
becomes bilious. Any child with bilious vomiting is assumed to have a condition that must be treated
surgically until proven otherwise.
• Parents also report the passage of stools that look like currant jelly.
• Lethargy is a relatively common presenting symptom with intussusception.
- Lethargy can be the sole presenting symptom, which makes the diagnosis challenging.
• Diarrhea can also be an early sign of intussusceptions. (early in the course of illness, the infant
evacuates the distal colon and passes several partially formed stools, which occasionally gives the
impression of diarrhea and children can often get misdiagnosed with gastroenteritis.

Physical
Upon physical examination, the patient is usually chubby and in good health. Intussusception is uncommon in
children who are malnourished. The child is found to have periods of lethargy alternating with crying spells, and
this cycle repeats every 15-30 minutes. The infant can be pale, diaphoretic, and hypotensive if shock has
occurred.

• The hallmark physical findings in intussusception are a right hypochondrium sausage-shaped

mass and emptiness in the right lower quadrant (Dance sign). This is hard to detect and is best
palpated when the infant is quiet between spasms of colic.
• Abdominal distention frequently is found if obstruction is complete.
• If intestinal gangrene and infarction have occurred, peritonitis can be suggested on the basis of rigidity
and involuntary guarding.
• Early in the disease process, occult blood in the stools is the first sign of impaired mucosal blood
supply. Later on, frank hematochezia and the classic currant jelly stools appear.
• Fever and leukocytosis are late signs and can indicate transmural gangrene and infarction.
• A rare presentation of intussusception is prolapse of the intussusceptum through the anus.
o This prolapse of the intussusceptum can be confused with rectal prolapse. Careful
examination can differentiate between the 2 presentations.
o The anal crypts are everted with rectal prolapse and not with intussusception.
o An examining finger can be passed between the prolapse and the anus in patients with
intussusception but not in patients with rectal prolapse.
• Patients with intussusception often have no classic signs and symptoms, which can lead to an
unfortunate delay in diagnosis and disastrous consequences.
Causes
In most infants and toddlers with intussusception, the etiology is unclear. This group is believed to have
idiopathic intussusception. One theory about the etiology of idiopathic intussusception is that it occurs because
of an enlarged Peyer patch.

• In approximately 2-12% of children with intussusception, a surgical lead point is found. Occurrence of
surgical lead points increases with age and indicates that the probability of nonoperative reduction is
highly unlikely. Examples of lead points are as follows:
o Meckel diverticulum
o Enlarged mesenteric lymph node
o Benign or malignant tumors of the mesentery or of the intestine, including lymphoma, polyps,
ganglioneuroma,3 and hamartomas associated with Peutz-Jeghers syndrome
o Mesenteric or duplication cysts
o Submucosal hematomas, which can occur in patients with HSP and coagulation dyscrasias
o Ectopic pancreatic and gastric rests
o Inverted appendiceal stumps
o Sutures and staples along an anastomosis
o Intestinal hematomas secondary to abdominal trauma
• Other theories have implicated a viral etiology; however, no theory has proven to be reliable.
• Familial occurrence of intussusception has been reported in a few cases. Intussusception in dizygotic
twins has also been described; however, these reports are extremely rare

Differential Diagnoses

Appendicitis
Colic
Cyclic Vomiting Syndrome
Gastroenteritis
Volvulus

Other Problems to Be Considered

Milk allergy
Incarcerated hernia
Internal hernia
Other rare causes of intestinal obstruction

Investigations

Laboratory Studies

• Laboratory investigation is usually not helpful in the evaluation of patients with intussusception.
• Leukocytosis can be an indication of gangrene if the process is advanced.
• Dehydration is depicted by electrolyte imbalances.
Imaging Studies

• After obtaining a thorough history and performing a careful physical examination, obtain plain
radiographs of the abdomen with the patient in the supine and upright positions.
o Plain abdominal radiography reveals signs that suggest intussusception in only 60% of the
cases.
o Plain radiograph findings may be normal early in the course of intussusception.
o As the disease progresses, earliest radiographic evidence includes an absence of air in
the right lower and upper quadrants and a right upper quadrant soft tissue density
present in 25-60% of patients.
o These findings are followed by an obvious pattern of small bowel obstruction, with dilatation
and air-fluid levels in the small bowel only. If the distention is generalized and the air-fluid
levels are also present in the colon, the findings more likely represent acute gastroenteritis
than intussusception.
o A left lateral decubitus view is also helpful. If the view exhibits air in the cecum, the presence
of ileocecal intussusception is highly unlikely.
• Ultrasonography is a noninvasive modality that can aid in making the diagnosis of intussusception. Its
accuracy reaches 100%.
o Hallmarks of ultrasonography include depiction of the intussusceptum and its mesentery
within the intussuscipiens (target and pseudokidney signs).
o Ultrasonography is highly operator dependent; therefore, interpret results with caution.
o It eliminates the risk of exposure to ionizing radiation and can help depict lead points and
residual intussusceptions.
o It helps to rule out other possible causes of abdominal pain.
o Sonographic detection of ascites, air, and absence of blood flow in the intestinal wall strongly
suggest bowel gangrene.
• CT scanning has also been proposed as a useful tool to diagnose intussusception; however, CT
findings are unreliable, and CT carries risks associated with intravenous contrast administration,
radiation exposure, and sedation.
• The gold standard for the diagnosis of intussusception in children is a contrast enema (either barium
or air).
o Contrast enema is quick and reliable and has the potential to be therapeutic.
o Exercise caution when performing contrast enema in children older than 3 years because
most of these patients have a surgical lead point, usually in the small bowel. The diagnostic
and therapeutic yield of the enema is lower in these patients.
o Enema is contraindicated in patients in whom bowel gangrene or perforation is suspected.

Treatment

Medical Care
Tailor treatment of the child with intussusception to the stage at presentation.

• For all children, start intravenous fluid resuscitation and nasogastric decompression as soon as
possible.
 • Nonoperative reduction with a diagnostic and therapeutic enema.
- The presence of peritonitis and any evidence of perforation revealed on plain radiographs are the
only 2 absolute contraindications to an attempt at nonoperative reduction with enema.
Therapeutic enemas can be hydrostatic, with either barium or water-soluble contrast, or pneumatic,
with air insufflation. Therapeutic enemas can be performed under fluoroscopic or ultrasonographic
guidance.
• Air enema is the treatment of choice in many institutions.
o The risk of major complications with this technique is small.
o Its success is decreased, as with other reducing agents, in patients with small bowel
intussusceptions and in those with prolapsing intussusceptions.
o When performing a therapeutic enema, the recommended pressure of air insufflation should
not exceed 120 cm of water. When using barium or water-soluble contrast, the column of
contrast should not exceed 100 cm above the level of the buttocks.
o Traditionally, an attempt was not considered successful until the reducing agent, whether air,
barium, or water-soluble contrast, was observed refluxing back into the terminal ileum, but
new evidence showed that this is not entirely necessary. Most intussusceptions that failed to
show reflux into the ileum were due to either an edematous or competent ileocecal valve.
• The value of repeated attempts at nonoperative reduction, if the first attempt is unsuccessful, has not
been determined. Some clinicians recommend taking the patient to surgical care if the first attempt
fails, and other clinicians advocate 1 or 2 subsequent attempts within a few minutes to a few hours
after the first attempt. Delay between the reduction attempts may place the patient in the "window" of
spontaneous resolution, which has been reported with an incidence of 5-6%. In addition, the first
attempt can reduce the intussusception partially, making the intussusceptum less edematous with
improved venous drainage. In CWMH, 3 attempts!
• When therapeutic enema is successful, the results are immediate and extremely gratifying. The infant
falls asleep almost immediately, and the obstruction is relieved, allowing the resumption of a normal
diet. A short period of overnight observation usually is warranted before discharge.
• Therapeutic enema is of no value in patients with small bowel–to–small bowel intussusception, which
usually occurs in older children.

Surgical Care
If nonoperative reduction is unsuccessful or if obvious perforation is present, promptly refer the infant for
surgical care.

• Traditional entry into the abdomen is through a right paraumbilical incision. Deliver the intussusception
into the wound and attempt nonoperative reduction. Milking the intussusceptum out of the
intussuscipiens is important. Sustain gentle manual pressure rather than pulling out the
intussusceptum to avoid risk of iatrogenic perforation. If operative reduction is successful,
appendectomy is often performed if the blood supply of the appendix is compromised. Risk of
recurrence of the intussusception after operative reduction is less than 5%.
• If manual reduction is not possible or perforation is present, perform a segmental resection with an
end-to-end anastomosis. A diligent search for any lead points is warranted, especially if the patient is
older than 2-3 years.
Diet

• A few hours after nonoperative reduction, start the infant on a regular age-appropriate diet as
tolerated.
• If operative reduction was performed, advance the diet as with any postoperative patient.

Medication

• Drug therapy is not currently a component of the standard of care for intussusception.

Follow-up

Further Inpatient Care

• With toleration of diet, patients treated with nonoperative reduction are usually discharged 12-18 hours
after the therapeutic enema. After operative reduction, postoperative progress dictates the length of
stay.

Further Outpatient Care

• Patients treated with nonoperative reduction usually do not require any specific follow-up care unless
problems exist.
• Postoperatively, patients require 1-2 visits to the pediatric surgeon to check on the progress of healing.

Deterrence/Prevention

• No measures are preventive for idiopathic intussusception.

Complications

• Complications rarely occur when the diagnosis is prompt, and they include the following:
o Perforation during nonoperative reduction
o Wound infection
o Internal hernias and adhesions causing intestinal obstruction
o Sepsis from undetected peritonitis (major complication from a missed diagnosis)

Prognosis

• Prognosis is usually excellent.

• Recurrence rate of intussusception after nonoperative reduction is usually less than 10% but has been
reported to be as high as 21%. Most intussusceptions recur within 72 hours of the initial event;
however, recurrences have been reported as long as 36 months later. More than one recurrence
suggests the presence of a lead point.
• The recurrence rates after air enema and barium enema are 4% and 10%, respectively.
• Recurrences respond to nonoperative reduction in almost 95% of cases.
Special Concerns

• Intussusception can be associated with various medical conditions or situations, which are usually
seen in patients older than 2-3 years. The intussusception is usually located from the small bowel to
the small bowel; therefore, therapeutic enemas are less helpful and are usually unsuccessful.
o Henoch-Schönlein purpura (HSP)
Children with HSP often present with abdominal pain secondary to vasculitis in the
mesenteric, pancreatic, and intestinal circulation. If pain precedes cutaneous
manifestations, differentiating HSP from appendicitis, gastroenteritis, intussusception,
or other causes of abdominal pain is difficult.
 Occasionally, children with HSP develop submucosal hematomas, which can act as
lead points and cause intussusception in the small bowel. Elucidating the cause of
the pain is essential in any child in whom HSP is suspected.
 Treating the pain of vasculitis with corticosteroids results in dramatic response.
 Patients with intussusception require surgery, rather than an enema, since the
intussusception is usually in the small bowel.
 Obtain plain radiographs of the abdomen with the patient in the supine and upright
positions to identify the small bowel obstruction present with intussusception. If
radiograph findings are normal, assume the patient has vasculitis and treat with
steroids.
o Hemophilia and other coagulation disorders: Patients with hemophilia and other coagulation
disorders can develop submucosal hematomas, which can cause pain and lead to
intussusception. Differential diagnosis includes retroperitoneal hemorrhage in addition to other
usual causes of abdominal pain. Radiographs of the abdomen should reveal a small bowel
obstruction pattern if intussusception is present. In the absence of intussusception, treatment
is supportive with correction of the coagulopathy.
o Postoperative intussusception: Intussusception is a rare complication in the postoperative
period. Complicating 0.08-0.5% of laparotomies, intussusception can occur regardless of the
site of the operation. Intussusception is assumed to occur because of a difference in activity
between segments of the intestine recovering from an ileus, which creates the
intussusception. Intussusception is suggested in any postoperative patient who has a sudden
onset of a small bowel obstruction after a period of recovery from an ileus, usually within the
first 2 weeks after surgery. Obstruction secondary to adhesions usually occurs more than 2
weeks after the operation. The treatment is prompt operative reduction.
o Indwelling catheters: Very rarely, indwelling jejunal catheters can lead to intussusception by
acting as a lead point, which is especially true if the tip of the catheter has been manipulated
or cut so that its surface is not smooth. Surgery is required to reduce the intussusception and
remove the tip of the catheter.
o Cystic fibrosis: Intussusception occurs in approximately 1% of patients. Intussusception is
assumed to be precipitated by the thick inspissated stool material that adheres to the mucosa
and acts as a lead point. Differential diagnosis includes distal intestinal obstruction syndrome
and appendicitis. Most of these patients require operative reduction

Nafiza Nisha
S070288 – MBBS 5