CIP Case of the Month

Intussusception. Submitted by Zachary L. Bercu, MD, Semo Siljkovic, RDMS, and Neil A. Lester, MD.cip

October 2012's most popular Case in Point (CIP) submission, as chosen by CIP users, was Intussusception." The winning case followed the management of a 22-month-old boy who presented with abdominal pain.

The submission was recognized for both its imaging and its discussion, and users commented that it was an "excellent instructive case" on an "extremely important" topic. The ACR Bulletin spoke with Zachary L. Bercu, MD, lead author and resident at Mount Sinai School of Medicine in New York, about intussusception and enema reduction.

Q: Why did you select "Intussuception" for submission to CIP?

A: On a single weekend call day, we had to patients from the emergency department present with concern for intussusception. One patient demonstrated a right lower-quadrant soft-tissue mass on abdominal radiography, which persisted on a left-lateral decubitus radiography, and was lethargic when we performed the ultrasound. This patient was found to be positive. The other patient had air throughout almost the entire cecum on abdominal radiograph, was alert crying during the ultrasound, and was found to be negative. The patient with intussusception went on to successful air enema reduction.

We felt the sequence of events represented a perfect teaching opportunity. A search of the CIP archive yielded some atypical intussusception cases after gastric bypass surgery, an irreducible ileocolic intussusception case with only plain film and contrast enema images, and cases secondary to ileal lipoma, appendiceal mucocele, and mesenteric adenitis. There was no classic case that had all three imaging modalities with successful reduction.

Q: What do you want users to learn from your case?

A: The most essential teaching points for us included the importance of ultrasound in diagnosis, the consideration of surgical consultation even for nonsurgical reduction given the risk of perforation or unsuccessful reduction, and the risk factors for decreased likelihood of successful nonsurgical reduction.

Time is critical in the prevention of morbidity and mortality for these patients, and the consistency of typical intussusception features makes it well suited to a standardized algorithm.

Q: When using ultrasound of diagnosis of intussusception, what findings are associated with a decreased likelihood of successful enema reduction?

A: In the literature, risk factors for decreased likelihood of successful nonsurgical reduction include atypical location (away from the ileocecal valve and suggesting a secondary cause such as a mass), intraperitoneal fluid trapped inside the intussusception, ileus, and symptomatic small bowel obstruction.

Q: Which enema procedure has the highest rate of reduction?

A: According to a 2009 article published in Pediatric Radiology1, air enema is considered more effective at reduction, cleaner at surgery in cases of perforation, faster, and safer. Air enema also likely requires less radiation than liquid enema. Recurrence rates are roughly similar for both air and liquid enemas (approximately 10 percent). Randomized controlled trials of reduction rates comparing the two have produced conflicting results. There are early reports in the literature of using ultrasound with water or air. However, studies of efficacy compared with fluoroscopy have not yet been performed. At our institution, we typically perform air enemas.

Q: What steps should be taken by pediatricians to prepare patients prior to enema reduction?

A: In preparation for enema reduction, patients should undergo surgical consultation and placement of an intravenous catheter. If the patient exhibits signs of dehydration, fluids should be given prior to reduction. If there are signs of peritonitis or perforation, surgical reduction should be performed instead.

"Intussusception" was published on October 22, 2012. To view the full case, visit http://bit.ly/intussusception.


ENDNOTE
1. Applegate KE. Intussusception in children: evidence-based diagnosis and treatment. Pediatr Radiol. 2009;39(suppl 2):S140–43.


By Anastasia Simkanin
Anastasia Simkanin (This email address is being protected from spambots. You need JavaScript enabled to view it.) is the CIP manager for the ACR Education Department.

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