Intussusception

PAEDIATRIC SURGERY II

IntussusceptionJoana Lopes

Simon N Huddart

AbstractIntussusception is the invagination of a segment of bowel into the distal

adjacent bowel. Mostly it involves the distal ileum and proximal colon and

no lead point can be identified. It is the most common cause of bowel

obstruction in infants and young children. It typically presents in infants

between 2 months and 2 years of age with episodic severe colicky

abdominal pain, vomiting that progresses to being bilious, abdominal

distension, and bleeding per rectum which is classically described as ‘red-

currant jelly’ stool. If not diagnosed and treated promptly the pathology

will progress to bowel necrosis, sepsis and death.

Patients usually need resuscitation and stabilization before investigation

anddefinite treatment. The diagnostic test of choice is an ultrasound scan of

the abdomen. The first-line treatment is an air-reduction enema that will be

successful in 80% of cases. Surgery with manual reduction of the intussus-

ception and possible bowel resection is reserved for cases presenting with

peritonitis, cases where a pathological lead point is identified, where air-

enema failed or where this procedure is complicated by bowel perforation.

Keywords Bowel obstruction; intussusception; redcurrant jelly

Introduction

Intussusception is definedas the invagination of a proximal segment

of intestine (intussusceptum) into the lumen of the adjacent more

distal segment of intestine (intussuscipiens). The intussusceptum

becomes the inner segment of intestine and the intussuscipiens the

outer segment of intestine in the intussusception.

Intussusception leads to bowel obstruction and if untreated

necrosis of the incarcerated bowel. It is the most common cause

of bowel obstruction in infants and young children.

History

1674e Intussusception was first described by Paul Barbette from

Amsterdam. The condition was invariably fatal.

1830e The first successful surgery was performed by John Wil-

son, but the surgical mortality was more than 75%.

1876e Harald Hirschsprung, a Danish paediatrician from

Copenhagen best known for describing congenital megacolon

and pyloric stenosis, first described hydrostatic reduction. The

diagnosis was clinical as radiographs were not available until

1895.

Joana Lopes MRCS is a Specialist Registrar in Paediatric Surgery at

University Hospital of Wales, Cardiff, UK. Conflicts of interest: none

declared.

Simon N Huddart MA MBBS FRCS FRCS(Paed) is a Consultant Neonatal and

Paediatric Surgeon at University Hospital of Wales, Cardiff, UK. Conflicts

of interest: none declared.

SURGERY 31:12 626

1959e Treatment of intussusception with insufflation of air

was first described by Fiorito from Argentina.

Epidemiology

The incidence in the UK is 1.6e4 cases per 1000 live births with

a male-to-female ratio of 3:2. It typically presents in infants

between 2 months and 2 years of age and 50% of the cases

present between 3 months and 10 months of age and 65% of the

cases before 1 year of age.

There is a seasonal variation in incidence with peaks in Spring

and Winter corresponding to peaks in occurrence of rotavirus

and adenovirus infections.

Aetiology/pathophysiology

In 95% of cases the intussusception is ileo-colic, arising in the

distal ileum and passing through the ileo-caecal valve into the

proximal colon. In decreasing frequency of occurrence it can also

be ileo-ileal, caeco-colic, colo-colic and jejuno-jejunal.

In 10% of cases a lead point (for example a polyp or hae-

mangioma) in the intestinal wall, driven by peristalsis in the

adjacent intestine, drags its associated segment of intestine (the

intussusceptum) into the distal bowel (the intussuscipiens).

In primary or idiopathic intussusception (90% of cases) a lead

point cannot be identified. It is thought that these idiopathic

cases might result from enlarged Peyer’s patches acting as a lead

point. Viral illnesses (upper tract respiratory infections and

gastroenteritis) may be the cause for the hypertrophy of the

lymphoid tissue. Adenovirus and to a lesser extent rotavirus have

been implicated in 50% of cases. The typical presentation

happens at the age of weaning occurs raising the possibility that

immune stimulation by newly introduced feeds may be a cause.

Food allergies are also considered to be a possible cause of

primary intussusception.

The incidence of intussusception increased in the USA after the

introduction of a rotavirus vaccine in 1998. Studies showed that the

risk increased 20e30-fold within 2weeks following the first dose of

the vaccine and three- to sevenfold within 2 weeks after the second

dose. Therewas no increased risk after the 3rd dose or 3weeks after

any of the doses. As a result, the vaccinewaswithdrawn a year after

being licensed.Twonewvaccinesagainst rotaviruswere licensed in

the USA (in 2006 and 2008). These had pre-licensure trials that

specifically evaluated the risk of intussusception and did not find it

tobe increased. Post-marketing surveillance is still ongoing.A study

that includeddataonmore than800,000dosesofoneof thevaccines

in the USA has not shown an increase in intussusception cases.

Postoperative intussusception (1% of childhood intussuscep-

tion) is another form of primary intussusception but a separate

entity on its own. It can happen following abdominal or thoracic

surgery, generally for malignancy, after retroperitoneal dissec-

tion and after chemo- or radiotherapy. It is usually ileo-ileal.

It is unclear why the intussusception develops but the current

belief is that it results from the proximal small bowel recovering

its peristalsis before the distal bowel and therefore being pushed

into the latter. It may also be due to spasm or oedema of the

bowel wall after surgery so acting as a lead point. Or it could be

due to dysmotility.

In secondary intussusception there is a pathological lead

point. Pathological lead points are more common outside the

Crown Copyright � 2013 Published by Elsevier Ltd. All rights reserved.

http://dx.doi.org/10.1016/j.mpsur.2013.01.001

Associated conditions seen with intussusception

C PeutzeJeghers syndrome e hamartous polyps act as

a lead point

C HenocheSchonlein Purpura e submucosal haematomas

act as a lead point. Intussusception seen in approximately

3.5% of patients with HenocheSchonlein purpura

C Cystic fibrosis e inspissated bowel contents act as a lead

point. Intussusception seen in approximately 1% of cystic

fibrosis patients

C Coeliac disease

C Clostridium difficile colitis

Note e Intussusception has been described in premature infants

and has been postulated as a possible cause for small bowel

atresia in neonates.

Box 2


typical age range with more than 20% seen in patients over 2

years of age. They are also more commonly ileo-ileal intussus-

ceptions and can recur if not excised.

Possible pathological lead points are listed in Box 1 and

associated conditions are listed in Box 2.

The first consequence of intussusception is bowel obstruction,

the second is compromise of the intussuscepted bowel: the

intussuscipiens distends, the intussusceptum and its mesentery

are compressed, and there will initially be lymphatic and venous

outflow obstruction, bowel wall oedema, followed by arterial

obstruction and eventually bowel necrosis.

Spontaneous reduction of intussusception undoubtedly

occurs. However, the natural history of the condition is to

progress to sepsis and death, unless it is recognized and treated

successfully.

Presentation

Over 80% of patients have episodes of colicky abdominal pain

with screaming, drawing up the legs and pallor. The episodes

recur every 10e20 minutes. Around 80% of patients vomit. This

may be early due to the pain or late due to obstruction when it

becomes bilious. Around a third of patients pass blood per

rectum with what is classically described as ‘redcurrant jelly’

stool. These are dark red mucoid clots that result from

compression of the mucous glands within the intussusceptum

plus bowel ischaemia and sloughing of the mucosa e this is

therefore a later sign. Most patients do not pass much stool after

they have emptied their colon since they are obstructed; however

up to 20% of patients may have had diarrhoea as a prodromal

illness. Only one-third of patients have the triad of colicky

abdominal pain, vomiting and bloody stools.

These are generally previously fit and well children, well

nourished and in good health. If early in the disease process,

between attacks the child may appear deceivingly well or asleep.

As the disease progresses, the child will become progressively

lethargic in between episodes of pain, progressively more dis-

tended due to ongoing obstruction, severely dehydrated and

shocked. Fever is a late sign due to bowel necrosis and sepsis.

Pathological ‘lead points’

C Meckel’s diverticulum

C Duplication cyst

C Polyp

C Appendix

C Ectopic pancreas

C Submucosal haematoma

C Inspissated bowel content

C Haemangioma

C Lymphoma

C Lipoma

C Carcinoid tumour

C Melanoma

C Foreign bodies (including trans-gastric-jejunal feeding tubes)

Box 1

SURGERY 31:12 627

In an episode of pain, the child may be difficult to examine,

there may be audible peristaltic rushes and a mass may be

palpable or even visible if the child is thin anywhere in the

abdomen. The classic examination finding is that of a right upper

quadrant sausage-shaped mass (present in 60e80% of cases).

Dance’s sign is the appearance of a flat or empty right lower

quadrant due to the mobile caecum having vacated the right iliac

fossa.

Rarely, the intussusceptum can be felt on rectal examination

or can be seen prolapsing through the anus. This needs to be

differentiated from a rectal prolapse as reduction of intussus-

cepted bowel misdiagnosed as a rectal prolapse could be life

threatening. If a lubricated tongue blade inserted along the side

of the protruding mass can be advanced more than 2 cm into the

anus the diagnosis of intussusception should be considered.

Postoperative intussusception tends to have an atypical

presentation and it should be suspected in any children with

prolonged or recurrent postoperative ileus. Mostly it happens

from 10 days to within a month post-surgery. It is usually ileo-

ileal. As postoperative functional ileus and adhesional

obstruction are more frequent causes for bowel obstruction

after surgery, intussusception may not be diagnosed.

Investigations

Imaging

An abdominal ultrasound scan (USS) is the preferred modality of

imaging to diagnose intussusception and often it will be the only

imaging needed. Its sensitivity and specificity approaches 100%

with an experienced operator. It may also distinguish between

ileo-ileal intussusception and ileo-colic intussusception guiding

further treatment.

The cross-sectional view of an intussusception on USS is

characterized by the ‘target sign’ (Figure 1) e two concentric

rings of low echogenicity separated by a ring of high echogenicity

representing the walls of the intussusceptum and intussusci-

piens. Longitudinally it is characterized by the ‘pseudo-kidney

sign’ (Figure 2) e superimposed layers of low and high echo-

genicity representing the oedema of the bowel walls. Doppler can

be used to detect blood flow within the intussusception.



Figure 1 Ultrasound scan showing ‘target sign’.


A plain abdominal X-ray is no longer the investigation of

choice but may have been taken and should be studied. The

radiograph may show the features of bowel obstruction and may

give the impression of a mass (an area of paucity of bowel loops

or an opacity within a gas filled bowel loop). The target sign or

coiled spring sign is an area of concentric lucencies that repre-

sents a cross-sectional appearance of the invaginated mesentery

and bowel into the intussuscipiens. The meniscus sign is a cres-

cent-shaped lucency in the colon that represents the outlining the

distal end of the intussusceptum by gas. The right iliac fossa is

usually gas free. However, the abdominal X-ray may be normal.

A contrast enema is rarely required to make the diagnosis but

where the diagnosis is not clear, it may be diagnostic and

therapeutic.

A pathological lead point should be considered in those over

2 years of age and those with recurrent intussusceptions. An

ultrasound and a contrast study may help, but CT or MRI may be

necessary.

Laboratory

Routine baseline blood tests need to be obtained. Due to the

dehydration, blood electrolytes and renal function need to be

assessed and corrected if needed. The blood loss associated with

intussusception rarely requires transfusion.

Management

The management follows the advanced paediatric life support

(APLS) algorithms remembering that these children can present

in a very unwell state and need resuscitation before further

investigation or treatment.

Figure 2 Ultrasound scan showing ‘pseudo-kidney sign’.

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Severe abdominal distension and pulmonary aspiration of

gastric content can lead to respiratory compromise. Bowel

obstruction, dehydration and ill-understood associated auto-

nomic changes in the vasculature can result in some children

having profound circulatory compromise and requiring signifi-

cant fluid resuscitation.

The patient requires an appropriately sized and functional

naso-gastric tube which is aspirated and then left on free

drainage for gastric decompression and secure intravenous

access. Sometimes supplemental oxygen and rarely endotracheal

intubation are required.

Fluid resuscitation may be needed to restore intravascular

volume with 0.9% normal saline or Hartmann’s given initially as

a 20 ml/kg bolus and then repeated up to two times if necessary

guided by monitoring with clinical reassessment to evaluate the

response to treatment. A blood transfusion might be needed if

high volumes of fluid are required and urinary catheterization

would then be appropriate. Hypothermia needs to be prevented

whilst patients are moved between different clinical areas (acci-

dent and emergency/radiology suit/theatre/ward). Intravenous

antibiotics (cefuroxime and metronidazole) should be started.

Only stabilized patients can thereafter undergo further

investigation and treatment.

Radiological reduction

An air-reduction enema under fluoroscopic guidance performed

in accordance with the guidelines of the British Society of

Paediatric Radiologists is the treatment of choice. Radiological

reduction used to be performed with barium under fluoroscopic

guidance for both diagnosis and treatment. Water-soluble

isotonic contrast has also been used as this does not carry the

risks of barium peritonitis if intestinal perforation occurs. Air-

enemas have been shown to be as equally effective and if

perforation ensues contamination is not as extensive. The

disadvantage of air-reduction is the poorer visualization of the

reduction and possible lead points and the risk of the develop-

ment of a tension pneumoperitoneum.

The procedure should only be undertaken once the child has

been resuscitated sufficiently.

The absolute contraindications to radiological reduction are

evidence of peritonitis or perforation and the identification of

a pathological lead point. Relative contraindications are the

presence of an ileo-ileal intussusception (as they are more diffi-

cult to reduce radiologically and have a higher incidence of

pathological lead points), a grossly distended abdomen and

children above the age of 3 years as they may be too uncooper-

ative for the procedure or maintain recollection of the events

which could be traumatic.

Consent should be obtained for the procedure with discussion

of the risks of failure, perforation, tension pneumoperitoneum,

cardiorespiratory collapse, need for emergency peritoneal

decompression and surgery, and of course recurrence.

The air-reduction enema takes place in the radiology suit with

adequate resuscitation equipment and expertise (APLS-trained

staff) available should the child deteriorate or arrest.

The procedure should be performed by an experienced radi-

ologist and an experienced member of the surgical team needs to

be present in order to manage the child if a tension pneumo-

peritoneum ensues.



Figure 3 Intraoperative picture of an intussusception that has been

delivered.


The child should be closely monitored throughout (heart

rate and pulse oximetry as minimum monitoring require-

ments). Antibiotics and opiate analgesia (usually as intrave-

nous morphine) are given before the start of the procedure

and naloxone should be available to be administered if

needed.

A catheter is inserted into the child’s rectum. The child is

immobilized, with the buttocks held together (in order to

achieve a tight seal around the catheter). The catheter is

attached to a pressure monitoring device, with a cut off at 120

mmHg.

Under fluoroscopic control air is insufflated into the colon to

achieve a pressure of 80e100 mmHg. This pressure is held for up

to 3 minutes in order to try and reduce oedema and then the

intussusception. Intermittent fluoroscopic screening allows one

to assess the progress of reduction of the intussusceptum. If the

first attempt fails the child should be allowed a rest before

a further attempt is made. With subsequent attempts the pressure

increases up to a maximum of 120 mmHg. Up to three attempts

are made. Successful reduction is demonstrated by the free flow

of air into the distal ileum. If doubt remains about the success of

the reduction (the IC valve may be too oedematous to allow air to

pass into the small bowel) then a repeat ultrasound scan may be

useful.

Success rates are between 75 and 80%. If symptoms have

been present for more than 48 hours the success rate is lower.

If reduction is successful the child is kept nil by mouth for

12hours beforefluids are allowed. If the child hadopiate analgesia,

monitoring needs to be continued for a periodof time as respiratory

depression may develop. Antibiotics can be stopped at 24 hours if

the child is well and discharge is usually possible within 48 hours.

If the procedure fails but the child is stable the procedure can

be repeated 2e4 hours later. If the child is not clinically well then

surgery is necessary.

Of note is the fact that recurrent intussusception can be

treated following the same principles as a first episode. The

success rate for air-enema is the same as for a first presentation,

even if it previously failed and surgery was needed.

The most significant complication of an air-reduction enema

is perforation of the bowel. If this occurs the high pressure gas

within the colon escapes and causes a tension pneumo-

peritoneum, which may compress the inferior vena cava and lead

to cardiovascular collapse. Immediate treatment is necessary

with insertion of a large-bore cannula into the abdomen to

release the pressure. Definitive management is by laparotomy.

The perforation can happen either under the form if a small

necrotic patch of bowel or a long linear tear along the anti-

mesenteric border of the bowel.

Surgery

Surgery is performed if there is a contraindication to radiological

reduction or, if this was unsuccessful, if radiological reduction

created a perforation or the parents have refused to give consent

to an air-reduction enema.

A transverse muscle-cutting incision is made on the right-

hand side of the abdomen, usually above the level of the umbi-

licus. The intussusception is delivered (Figure 3) (it is occa-

sionally necessary to mobilize the colon to achieve this).

Moderate serous ascites may be found due to the obstruction.

SURGERY 31:12 629

Once the edge of the intussusceptum is found this is gently

manipulated back upstream. Mild pressure can decrease the

oedema and help with the manoeuvre. Pulling the intussuscep-

tum should not be attempted, as it is likely to cause tearing or

perforation. If the intussusception is reduced the bowel must be

assessed for viability and to examine for a lead point. It is

important to realize that the first part of the intestine to invagi-

nate and the last part to reduce may be particularly thickened

and indented. This is commonly seen and is not a pathological

lead point and does not need resection.

Inability to reduce the intussusception, concerns over the

viability of the bowel or identification of a pathological lead

point require a resection (needed in approximately one-third to

one-half of cases) this might be a simple resection or a limited

right hemicolectomy with an end-to-end anastomosis or rarely

a diverting stoma depending on the condition of the bowel and

child.

An incidental appendicectomy may be performed especially if

a lower incision has been selected.

Postoperatively the child should have a naso-gastric tube in

place, receive adequate analgesia, fluids and antibiotics and be

monitored closely. Normally it is possible to start oral fluids 12e

24 hours after once any ileus has settled. Patients should only be

discharged when eating and stooling normally.

Laparoscopy started being used for diagnostic purposes only.

However its role in managing intussusception is evolving with

some surgeons are using it to attempt reduction only and if

unsuccessful they proceed to a laparoscopic-assisted procedure

(by exteriorization of the bowel through a periumbilical incision)

or converting to open, but some centres are using laparoscopy

even if bowel resection is needed.

The majority of surgeons will be using a three-port technique

(one infraumbilical port, two ports on the left-hand side of the

abdomen). An atraumatic bowel clamp is used to grasp the

intussusceptum and an intestinal grasping forceps is used to hold

the caecum. The caecum is then pushed away while pressure is

applied distal to the intussuscipiens.

The main difference from the open technique is that traction

on the proximal bowel is usually required.




Outcome

If diagnosed and treated promptly, the current prognosis of

intussusception is excellent, with patients having no long-term

complications.

There is a 1% risk of perforation with air-enema reduction,

more likely if the history is long (>48 hours). Post-perforation

the main risk is respiratory compromise due to tension pneu-

moperitoneum that needs to be decompressed immediately, any

peritoneal contamination tends to be minimal.

The recurrence rate is less than 5%. In 30% of cases it occurs

within 24 hours, in 70% of cases within 6 months. Recurrence is

less likely after surgical treatment.

Intussusception has a mortality (<1%) with deaths associated

with a delay in diagnosis, inadequate fluid resuscitation, inade-

quate antibiotic cover and failure to recognize recurrent or

residual intussusception following reduction.

SURGERY 31:12 630

Future

Slow hydrostatic reduction with saline enema under ultrasound

guidance has been reported in China with 95.5% of 5218

patients having successful reduction and a perforation rate of

0.17% with no mortality. This method has the advantage of not

requiring radiation and might be an alternative to current

practice. The likely increased reduction rate may be due to the

time over which reduction takes place. Oedema may be more

likely to resolve with gentle pressure applied over a longer time

than with the three short, sharp, high-pressure periods currently

employed. A

FURTHER READING

Grosfeld JL. Pediatric surgery. 6th edn. Philadelphia: Mosby Elsevier, 2006.



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Intussusception