How not to miss - intussusception

Worst outcomes if missed

Death - intussusception is a ‘telescoping’ type phenomenon whereby one segment of bowel (intussusceptum) passes or invaginates inside an adjacent distal segment (intussuscipiens).This process results in venous congestion and bowel wall oedema. Symptoms of intestinal obstruction develop causing pain, vomiting and, in the later stages, blood stained stool (redcurrant jelly stool). If left untreated the arterial supply becomes obstructed leading to bowel necrosis, perforation and peritonitis. If the diagnosis is missed the patient could die.¹

Epidemiology

Intussusception is one of the most common true paediatric surgical emergencies in the first two years of life.

Incidence is between 1.5 and 4 cases per 1000 live births per year.
70% of cases are under one year of age but intussusception can occur at any age. The peak incidence is around nine months of age.
In children under two, the cause or ‘lead’ point of the intussusception is thought to occur from reactive hyperplasia of the distal ileal lymphoid tissue (Peyer’s patches), which may be the result of a preceding viral illness such as a upper respiratory tract infection.
In older children the lead point is more likely to be a pathological lesion such as a Meckel’s diverticulum, duplication cyst, polyp or solid tumour.
Boys are more commonly affected than girls (3:2).
Following reduction of the intussusception there is a 7-15% risk of recurrence usually happening within 2–3 days and this may indicate a pathological lead point.²

Symptoms and signs

Presentation is acute with progressive abdominal symptoms including:

Colicky, intermittent abdominal pain occurring at intervals of 15-20 minutes.
Drawing up of legs and inconsolable crying.
Exhaustion and lethargy between spasms.
Pain becomes continuous after 12 hours or so.
Vomiting, initially non-bilious and in the later stages bilious.
Normal or loose stool.
In the later stages they may pass the classical blood stained (redcurrant jelly) stool.

On examination:

The child may look pale, clammy and lethargic.
Abdominal distension.
In 50% of children a ‘sausage shaped’ mass is palpable in the right upper quadrant.
Bloody rectal discharge after rectal examination (late finding)

Differential diagnosis

If you suspect an intussusception the child should be urgently referred to hospital without hesitation. However, differential diagnoses include:

Strangulated hernia – presenting with obstruction and a palpable irreducible groin lump (also a surgical emergency).
Malrotation/volvulus – presents with bilious vomiting from the outset and usually occurs in the first month of life (also a surgical emergency).
Gastroenteritis – may have a similar presentation but the volume of diarrhoea will be greater.
Cow’s milk intolerance – can present with abdominal pain and bloody stools. However, symptoms are less severe, have an element of chronicity, and may be associated with rashes or eczema and failure to thrive.
‘Wind’ colic – rarely lasts longer than an hour, usually not associated with vomiting and frequently a recurrent problem.

First-line investigations and treatment

All suspected patients should be kept nil by mouth and urgently seen in hospital where the following will occur:

Correction of dehydration with IV fluid resuscitation.
Abdominal X-ray demonstrates abnormal distribution of intestinal gas or (late finding) bowel obstruction with a right-sided soft-tissue mass. Free air confirms perforation requiring urgent surgery
Abdominal ultrasound shows the pathognomic ‘target sign’ (one bowel lumen lying inside another)
Immediate non-surgical reduction under X-ray guidance, which is successful in about 75-85% of cases. The hydrostatic or air-enema creates a sustained intra-colic pressure, which pushes the invaginated bowel out from the distal segment thus reducing the intussusception. Successful reduction is signified by a ‘flood’ of air into the distal lumen.
If the hydrostatic or air-enema reduction is unsuccessful then surgery is performed by laparoscopic or open approach during which the intussusceptum is gently ‘milked’ from the intussuscipiens. If bowel necrosis is present then bowel resection and anastomosis is performed

Five red herrings

Just because the child has previously been treated for intussusception doesn’t mean it can’t recur (7-15% recurrence rate).
Less than a quarter of patients present with the classic triad of symptoms (abdominal pain, vomiting and redcurrant jelly stool). Absence of ‘classic’ symptoms should not deter clinical suspicion and delay referral to hospital care.³
Children can present with non-specific symptoms and signs, which can make the diagnosis difficult.
Although uncommon in children less than six months of age, intussusception can still occur.
A previous history of similar self-resolving symptoms could indicate intermittent intussusception. If symptoms are present the patient should been seen urgently in hospital.

Five key questions

Has the child experienced episodes of inconsolable crying and abdominal pain?
Has the child been drawing up the legs with or without obvious episodes of abdominal pain?
Is the child more lethargic/pale/behaving differently to normal?
Has there been any vomiting or blood stained stool?
What is the onset and duration of the symptoms?

Miss Helen Carnaghan is a paediatric surgery registrar and academic clinical fellow at the UCL Institute of Child Health. Mr Massimo Garriboli is a consultant in paediatric surgery urology at St George’s Healthcare NHS Trust

References

Waseem M, Rosenberg HK. Intussusception. Pedatr Emerg Care. 2008;24(11):793-800
Chien M, Willyerd FA, Mandeville, et al. Management of the child after enema-reduced intussusception: Hospital or Home? J Emerg Med. 2013;44(1):53-7.
Samad L, Marven S, El Bashir H, et al. Prospective surveillance study of the management of intussusception in UK and Irish infants. Br J. Surg. 2012;99(3):411-5