INTUSSUSCEPTION

Oscar Navarro K.

The Hospital for Sick Children

University of Toronto

Objectives

Review role of ultrasonography in the diagnosis of intussusception

Describe advantages and disadvantages of the different enema reduction techniques

Discuss particular types of intussusception, including those due to pathologic lead points and those limited to the small bowel

What is intussusception?

Invagination of a segment of bowel into another

Broad definition that includes

conditions of no clinical significance

others that require prompt treatment due to the risk of bowel necrosis

What type of intussusception?

Limited to small bowel vs. colonic involvement

Asymptomatic vs. symptomatic

Due to lymphoid hyperplasia vs. pathologic lead point

Ileocolic and ileo-ileocolic intussusceptions

Most common of those requiring treatment

Usually symptomatic

Often due to lymphoid hyperplasia

Clinical diagnosis

Abdominal pain 83-85%

Vomiting 48-80%

Abdominal mass 22-65%

Blood in stool (occult or gross) 43-60%

Clinician often has to rely on imaging

Diagnosis

Sonography is cornerstone modality

Highly accurate

May identify pathologic lead points

Lack of radiation and non-invasiveness

Sonography: High accuracy

100% accuracy

Pracros et al, 1987 (Lyon, France)

Wang & Liu, 1988 (Shenyang, China)

Woo et al, 1992 (Daegu, South Korea)

Riebel et al, 1993 (Berlin, Germany)

Lim et al, 1994 (Seoul, South Korea)

Del Pozo et al, 1996 (Madrid, Spain)

Sonographic appearance

2-5 cm mass

Just deep to abdominal wall

Characteristic appearance

- “doughnut” and “target” signs

- “pseudokidney” and “sandwich” signs

del-Pozo et al. Radiographics 1999; 19:299-319

Sonography in intussusception False positives

Bowel wall thickening

Volvulus

Psoas muscle

Feces

Treatment of intussusception

Non-operative management: enema

High reduction rates

Less invasiveness and morbidity

No anesthesia

Short hospital stay

Decreased costs

Candidates for enema reduction

Relative contraindications:

dehydration - correction before

shock enema

Absolute contraindication:

peritonitis - surgery

Clinical findings and reducibility

Younger age

Rectal bleeding

Radiographic signs of obstruction

Longer duration of symptoms

Successful reduction can be achieved in the presence of any of these factors

Sonographic assessment of reducibility

Thick peripheral hypoechoic rim

Free intraperitoneal fluid

Trapped fluid within intussusception

Enlarged lymph nodes in intussusceptum

Pathologic lead point

Absence of blood flow

7m♀: bloody stools, lethargic

Sonographic assessment of reducibility

The preoperative diagnosis of bowel necrosis remains a challenge

Enema reduction techniques

Hydrostatic vs. Pneumatic

Fluoroscopy vs. Sonography

Pneumatic under fluoroscopy

Advantages: Generally easy, quick, clean Less radiation than barium enema Pinhole perforations and less contamination

Disadvantages: Radiation Difficult in patients with distended bowel Risk of tension pneumoperitoneum in

perforation

Hydrostatic under sonography

Advantages:

No radiation

Direct visualization of reduction, edematous ileo-cecal valve, residual intussusception and pathologic lead point

Disadvantages:

?Larger tears / more contamination in perforation

Longer procedure

Messier (excess fluids)

Complications of any technique: perforation

Present prior to enema due to necrosis

Secondary to enema even at low pressure

Rare event <1%

More common in young children <6-7mo with a longer duration of symptoms >36-48h

Perforations are smaller and easier to deal with when secondary to pneumatic reduction

Experimental peritoneal soiling: safety

air > saline > water-soluble contrast > barium

Delayed repeated reduction attempts

10-14% of irreducible intussusceptions undergo spontaneous reduction

51-66% manually reduced without bowel resection

Partial reduction may relieve congestion facilitating subsequent reduction attempt

Delayed repeated reduction attempts

Series Interval Cases Success rate (%)

Red rate without

Red rate with

Navarro, 2004

18m-12h 26 (12%) 50 84 90

Sandler, 1999

2h-19h 17 (n/a) 59 n/a n/a

González-Spínola, 1999

30m-24h n/a n/a 71 82

Gorenstein, 1998

45m-60m 19 (52%) 83 48 91

Saxton, 1994

30m-3h 21 (15%) 52 78 86

Delayed repeated reduction attempts

Safe and effective

Performed if initial attempt moves intussusceptum

Patient clinically stable

No optimal interval

Number of attempts weighed against risks of radiation

Recurrence of intussusception

Literature ~ 10% (SickKids 2004 19%)

2/3 have only 1 recurrence

Usually within first few days

High reducibility

Most no documented pathologic lead point 67-100% (SickKids 2004 75%)

Success of non-operative management

Not only enema reduction rate (highest possible)

Also number of manually reduced at surgery without bowel resection (lowest possible)

Intussusception due to pathologic lead points

Incidence 1.5-12% (SickKids 2004 8%)

Wide spectrum

Varied and nonspecific presentation

Diagnosis is relevant as management may be different

Pathologic lead points

Clinical clues:

Predisposing disease (Peutz-Jeghers, polyposis, HSP, celiac disease, CF, neutropenic colitis)

Age of patient

Lymphoma suspected in child >3y, long duration of symptoms and weight loss

Recurrences (SickKids 2004 25% vs. 5%)

Pathologic lead points

Focal:

Meckel diverticulum

Intestinal polyp

Duplication cyst

Lymphoma

Diffuse:

Henoch-Schönlein purpura

Cystic fibrosis

Celiac disease

Diagnosis of pathologic lead points

Sonography is modality of choice

Detection of 74% of focal PLP

Specific diagnosis of 32% of focal PLP

Diagnosis of all cases of duplication cyst

Meckel diverticula and polyps are more difficult to detect

Management of intussusceptions due to pathologic lead points

Successful reduction with AE in 60-64%

Enema reduction also recommended in PLP that will require surgery

Small bowel intussusception

Spectrum of presentations

Includes common, benign, transient event in asymptomatic or mildly symptomatic children

Persistent, large, symptomatic intussusception with a pathologic lead point

Transient small bowel intussusception

More frequently reported with increasing use of sonography and CT

In asymptomatic patients or mildly symptomatic children with or without underlying predisposing pathology (gastroenteritis, celiac disease, abdominal trauma, ALL-neutropenic colitis)

Transient small bowel intussusception

One or more

In left hemiabdomen or centroabdominal

Active peristalsis

Small diameter US: < 2.4cm (mean 1.8cm)

CT: < 3cm (mean 2.1cm)

Short segment US: < 2.7cm (mean 2.3cm)

CT: < 5cm (mean 2.2cm)

5y, ALL, neutropenia, abdominal pain

Initial CT Delayed images

5y MVA- Duodenal hematoma Pelvic fractures

11m SCID Candidiasis

4y ALL Neutropenia Abdominal pain

9y Fell from bike Liver trauma with portal vein injury

4y Heart tx Routine f/u

13y Celiac disease

Transient small bowel intussusception

Not all intussusceptions require reduction

Spontaneous reduction expected in children with characteristic appearance of transient small bowel intussusception

Symptomatic small bowel intussusception

Symptoms similar to ileocolic

Higher incidence of PLP

Most eventually require surgery

Symptomatic small bowel intussusception

Larger than transient SB intussusception diameter 2-4.3cm (mean 2.9 cm)

Variable length

PLP may be identified on sonography

Ileo-ileal intussusception - HSP

3y♀: abdominal pain x 5d

Summary

Sonography is modality of choice for diagnosis

Multiple management options

Decreasing radiation and complications

Patient’s comfort and safety

Continuous evaluation of our techniques

Open to accept new techniques