intussusception: a guide to diagnosis and intervention in children

Intussusception: A Guide to Diagnosis and Intervention in Children

Genevieve Daftary, Harvard Medical School,

Year IIIGillian Lieberman, MD

Genevieve Daftary, MS3Gillian Lieberman, MD

November 2005

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The Anatomy of Intussusception

Intussusception occurs when a segment of bowel, the intussusceptum, telescopes into a more distant segment of bowel, the intussuscipiens

The most common type is ileocolic (pictured here), followed by ileoileocolic, ileoileas, and colocolic

Radiologic Clinics of North America 1997

www.yoursurgery/Intussusception.jpg

Intussuscipiens


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Radiologic Clinics of North America 1997; Pediatrics 20003

Demographics

Most common acute abdominal disorder of early childhood (56 children/ 100,000/ year in US)

Boys 4x’s more frequently than girls

Majority of patients between 3 mon and 3 yr– Peak incidence between 5 and 9 months– 75% under 2 years

Seasonal peaks in spring and autumn

95% no pathologic lead point

5-10% recognizable lead point

Some evidence of significant attributable risk with rotavirus vaccine administration


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Radiologic Clinics of North America 1996,19974

Etiologies of Intussusception

Idiopathic: no defined lead point– Association with viral illness (adenovirus)– Hypertrophy of lymphoid tissue

Recognizable cause for lead point– Meckel’s diverticulum– Intestinal polyp– Enteric duplication– Lymphoma– Intramural hematoma– Ameboma– Henoch-Schönlein purpura


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Radiologic Clinics of North America 1996, 19975

Clinical Presentation: VARIABLE

Intermittent, colicky cramping, pain

Later development of lethargy and somnolence

Vomiting (may be bile-stained)

Current jelly stool (blood and mucus)

Sausage shaped mass

Distention and tendernessClassic Triad: abdominal pain, currant jelly stool,

palpable abdominal mass (<50%)


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Radiologic Clinics of North America 19976

Complications

Typically do not occur within the first 24 hrs…

Bowel obstruction

Intestinal ischemia

Perforation

Shock

Sepsis

Dehydration…thus we have a window of opportunity in which

to treat and avoid surgery.


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AJR 2005; Rad Clinics of N Amer 19967

Overview of Screening Tools

Abdominal Radiograph– Screen for other Dx’s and free air– Can be safely omitted in the presence of US– 45% sensitivity

Abdominal Sonography– Diagnostic accuracy near 100%, eval of reducibility, +/- lead

point, post reduction, ischemia

Abdominal CT scan– Accuracy approaching 100%; especially good for lead points– High cost, risk of radiation, and risk of sedation in children

make it unpractical


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Children's Hospital Boston8

Patient One: Presentation

6 year old female

3 weeks ago: URI w/ fever, vomiting, diarrhea (greenish, non-bloody), abdominal pain; seemed to resolve after 3 days

1 week ago: increasingly lethargic and irritable, w/vomiting and fever


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Patient One: Supine KUB


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Patient One: Supine KUB

Paucity of Gas on Right Side of Abdomen


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Radilogic Clinics of North America 1996; Amer J Rad 200511

Abdominal Radiograph

Signs of Intussusception– Soft tissue mass– Target sign: created by mesenteric fat– Absence of cecal gas and stool– Meniscus sign: crescent of gas outlining intussusceptum– Loss of visualization of the tip of the liver– Paucity of bowel gas

Poor sensitivity for dx of intussusception: 45%

May be useful to exclude other Dx

Determine presence of free air (contraindication to non- surgical reduction with contrast)

May be safely omitted if ultrasound is available


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RadioGraphics 199912

Target & Meniscus Signs


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Target & Meniscus Signs


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Patient One: Longitudinal Ultrasound


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Patient One: Longitudinal Ultrasound

•Telescoping Bowel

•Sandwich Sign/ Pseudokidney


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Patient One: Axial Ultrasound


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Patient One: Axial Ultrasound

Doughnut/ Target Sign


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Patient One: Doppler Ultrasound


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Patient One: Doppler Ultrasound

•Blood flow maintained

•Rule out ischemia of involved bowel


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Rad Clinics of N Amer 199720

Abdominal Ultrasound

Replaced abdominal radiograph as primary screening modality

Sensitivity 98 -100%; specificity 88 -100%

Appearance: outer hypoechoic region surrounding an echogenic center or multiple concentric rings

Use Doppler to determine bowel ischemia; guides reduction decisions

Guide hydrostatic and pneumatic reduction


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Ultrasound Cross-Sections

• A = intussuscipiens

• B = everted intussusceptum

• C = central intussusceptum

• M = mesentery

• L = lymph nodes

• MS = contacting mucosal surfaces

• S = contacting serosal surfaces


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Patient One: Air Enema

Normal bowel gas pattern: Spontaneous Reduction


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Enemas

Air, Liquid (saline, soluble contrast), Barium

At one time used for Dx– Coiled spring: edematous mucosal folds of returning

intussusceptum outlined by contrast in colon– Meniscus sign

Now used mainly for Treatment/Reduction– Avoid patient discomfort and risk of perforation– US better diagnostic tool & rule out tool


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Meniscus & Coiled Spring Signs


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Radiology 2001; AJR 2004 & 2005; Rad Clinics of N Amer 199625

Reduction Procedures

Barium enema: previous standard for Dx and reduction– Risk of barium peritonitis, infection, adhesions,

radiation exposure with fluoroscopy, only see lumen– 55-95% accuracy– Iodinated contrast safer but causes fluid shifts

US-guided Hydrostatic reduction– No radiation, good visualization of intussusception &

lead points– Need sonographer


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Radiology 2001; AJR 2004 & 2005; RadioGraphics 199926

Reduction Procedures cont.

Pneumatic reduction with fluoroscopic guidance– Quick, safe, clean (less fecal spillage), cheap– Radiation exposure, cannot depict lead points well, only see

intraluminal content

US-guided Pneumatic reduction– No radiation, confirm dx, highest successful reduction rate

(92%), quick and clean, can see lead points well (but not all)– Air blocks US beam; difficult to see ileocecal valve and

residual intussusceptions

Surgical


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Rad Clinics of N Amer 199627

Contraindications to Enema

Dehydration

Peritonitis

Shock

Sepsis

Free air on radiographStabilize then treat surgically


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AJR 200528

Complications of Reduction

Perforation– Overall rate of 0.8%– Similar rates for liquid and air enemas– Perforations with air usually smaller

Recurrence– Approximately 10%– Similar rates for liquid and air enemas– 50% will occur within 48 hrs– Repeat enemas are safe and effective


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AJR 200529

Reduction Guidelines

Liquid Enema Rule of Three’s for Barium– 3 attempts– 3 min duration– Liquid enema bag 3 feet above fluoroscopy table (5

feet if using water-soluble contrast)

Air Enema– Ensure maximal pressures <120 mm Hg at rest


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AJR 2002 & 200530

Success of Reduction Depend On…

Short duration of symptoms (<24-48 hrs)

Adequate hydration

Age (older than 3 months)

Absence of small-bowel obstruction

Absence of trapped intraperitoneal fluid

Absence of enlarged lymph nodes in the intussusceptum

Adequate blood flow

Location other than the rectum (rectum only 25% success)


November 2005


Patient Two: Presentation

2 year old male

Worsening vomiting and abdominal pain since the morning of admission

Vomited 8x’s since morning, no bile, blood or stool

No fevers; no current or recent illness

No new foods, travel or trauma

Prior incident of vomiting which he recovered from one month prior

Abdomen soft, non-distended with active BS, diffusely tender


November 2005


Patient Two: Supine KUB

Patient does not have classic triad of intussusception

Use KUB to consider other diagnoses


November 2005


Patient Two: Supine KUB

•Paucity of Gas on Right

•Dilated loops of small bowel

•Looks like obstruction


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Felson, Gamuts in Radiology34

DDx of Intestinal Obstruction in a Child

Adhesions/Congenital peritoneal bands (Ladd’s bands

Appendicitis

Hernia, incarcerated (internal or external)

Hirschsprung disease

IntussusceptionUncommonly: Crohn’s, fecal impaction, bezoar,

Kawasaki , neoplasm, congenital stenosis, TB, volvulus, CF, Chronic granulomatous disease


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Patient Two: Longitudinal Ultrasound

Use US to explore possible causes of obstruction including intussusception

Patient is not exposed to any further radiation or the discomfort of enema until further Dx


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Patient Two: Sagittal Ultrasound

Dilated loops of bowel


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Patient Two: Axial Ultrasound


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Patient Two: Axial Ultrasound

•Doughnut/Target Sign

•Patient’s obstruction is due to intussusception


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Patient Two: Doppler Ultrasound


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Patient Two: Doppler Ultrasound

•Blood flow maintained

•Rule out bowel ischemia

•Patient is safe to receive an US guided air enema with likelihood of resolution


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Review

Intussusception is COMMON in young children

Clinical presentation is variable underscoring the need for a safe, quick, inexpensive screening tool such as ultrasound

Ultrasound is extremely accurate in diagnosing obstruction; CT is more accurate in defining a lead point; abdominal radiographs can be helpful in considering other diagnoses

Ultrasound guided air enema combines the safety of ultrasound (lack of radiation) with the effectiveness, ease, cleanliness, and safety of air enema in reducing intussusception


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What does intussusception look like on CT?

Since lead points are more likely in the adult population, CT is done more frequently in this population with suspected intussusception

Scroll through the following images to get a sense of what intussusception looks like on CT

Notice the familiar target sign, also useful in diagnosis using plain film and ultrasound!


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Intussusception on CT


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References

Applegate KE. Clinically Suspected Intussusception in Children: Evidence-Based Review and Self-Assessment Module. AJR 2005; 185: S175-S183.

Daneman A and Alton J. Intussusception: Issues and Controversies Related to Diagnosis and Reduction. Radiologic Clinics of North America 1996; 34: 743-756.

Del-Pozo G et al. Intussusception in Children: Current Concepts in Diagnosis and Enema Reduction. RadioGraphics 1999; 19: 299-319.

Felson. Gamuts in Radiology.

Koumanicou C et al. Sonographic Detection of Lymph Nodes in the Intussusception of Infants and Young Children. AJR 2002; 178: 445-450.

Navarro O, Daneman A, Chae A. Intussusception: The Use of Delayed Repeated Reduction Attempts and the Management of Intussusceptions Due to Pathologic Lead Points in Pediatric Patients. AJR 2004; 182: 1169-1176.

Parashar UD et al. Trends in Intussusception-Associated Hospitalizations and deaths Among US Infants. Pediatrics 2000; 106: 1413-1421.

Sivit CJ. Gastrointestinal Emergencies in Older Infants and Children. Radiologic Clinics of North America 1997; 35: 865-877.

Yoon CH, Kim HJ, Goo HW. Intussusception in Children: US-guided Pneumatic Reduction—Initial Experience. Radiology 2001; 218: 85-88.


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Acknowledgements

Special Thanks To…– Melissa Gerlach, MD– Anne-Catherine Kim, MD– Larry Barbaras, Webmaster– Pamela Lepkowski– Gillian Lieberman, MD

intussusception: a guide to diagnosis and intervention in children

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