Pediatric Intussusception Surgery Workup

Updated: Jul 18, 2019
  • Author: Amulya K Saxena, MD, PhD, DSc, FRCS(Glasg); Chief Editor: Harsh Grewal, MD, FACS, FAAP  more...
  • Print
Workup

Laboratory Studies

Obtain a complete blood count (CBC) with differential and chemistry profile. Blood chemistry abnormalities are not specific for intussusception. Depending on the duration of illness and associated vomiting and blood loss, laboratory investigations may reflect dehydration, anemia, leukocytosis, or a combination of these.

Next:

Plain Radiography

Early in the course of the illness, findings on plain radiographic examination of the abdomen (supine and upright) may be unremarkable. Findings suggestive of intussusception include dilated loops of small bowel with or without air-fluid levels, an airless or opacified right lower quadrant (RLQ; see the image below), or both. Occasionally, the intussusceptum is apparent on plain abdominal radiography.

Abdominal plain radiograph of 14-week-old patient Abdominal plain radiograph of 14-week-old patient with intussusception. Note nonspecific appearance of bowel obstruction.

In order to increase the diagnostic accuracy, a left-side-down decubitus radiographic view of the abdomen can be helpful. Hooker et al found that the diagnostic value of kidney-ureter-bladder (KUB) radiography increased from 60.3% to 74.1% after a decubitus view was added. [21]  With the addition of the decubitus view, the exclusion value was also increased, from 25.6% to 58.1%.

Roskind et al used three radiographic views (supine, prone, and left decubitus) and found a sensitivity of 100% when these three showed air in the ascending colon, but a specificity of only 18.4%. The sensitivity went to 96% and specificity to 41% when at least two views revealed air in the ascending colon. [22]

 

Previous
Next:

Ultrasonography

First reported as a useful diagnostic tool in intussusception by Burke in 1977, ultrasonography (US) has been shown by a number of authors to be helpful in the diagnosis of intussusception. [23]  Studies advocating its use for diagnosis have reported sensitivities of 98.5-100%, specificities of 88-100%, and negative predictive values of 100%. US has been described as being the imaging method of choice for ileocolic intussusception in children. [24]

Characteristic findings on US include a target sign (see the first image below) visible on transverse section and a pseudokidney sign (see the second image below) viewed on longitudinal section.

Transverse ultrasonographic view (target sign) of Transverse ultrasonographic view (target sign) of intussusception.
Longitudinal ultrasonographic view (pseudokidney s Longitudinal ultrasonographic view (pseudokidney sign) of intussusception.

US has also been studied as a tool for helping to differentiate the types of intussusception. [25]  Park et al reported that a transient small-bowel intussusception is most likely characterized by the following [26] :

  • Location in the RLQ or periumbilical region
  • Smaller anteroposterior diameter (1.38 cm vs 2.53 cm)
  • Thinner outer rim (0.26 cm vs 0.53 cm)
  • Absence of lymph nodes, in contrast to ileocolic intussusception

A study by Munden et al supported these findings, with a mean anteroposterior diameter of 1.5 cm in ileoileal intussusceptions and 3.7 cm in ileocolic intussusceptions and mean lengths of 2.5 cm and 8.2 cm, respectively. [27]

With small-bowel intussusception, the length may be helpful in determining the necessity of surgery. Munden et al found that an intussusception length of more than 3.5 cm independently predicted the likelihood of surgery being performed, with a sensitivity of 93% and a specificity of 100%. [12]

US is best employed as a diagnostic tool of exclusion when the index of suspicion for intussusception is lower.

Previous
Next:

Computed Tomography

The evaluation of abdominal pain often leads to examination with computed tomography (CT). Although CT is not indicated for the diagnosis of intussusception, intussusception can be found incidentally on CT scans (see the image below).

Appearance of intussusception on CT scan. Appearance of intussusception on CT scan.
Previous
Next:

Procedures

Diagnostic and therapeutic enema

Ladd first used barium enema as a diagnostic tool in 1913. [28]  Since that time, enemas, with either air or barium, have become a mainstay in both diagnosis and therapy, replacing surgery as the initial management of stable patients. Knowledge of the basic technique and potential complications of contrast enemas in intussusception is important for all clinicians involved in the management of these patients.

A discussion of the choice between air (see the first image below) or barium (see the second image below) in contrast enemas is beyond the scope of this article, and the reader is referred to a number of reviews discussing the advantages and disadvantages of both techniques. [24]   Perforation is a risk with either barium or air but poses less of a problem with air, in that the combination of barium and feces may result in severe peritonitis with wide peritoneal soilage.

Ileocolic intussusception is observed by using air Ileocolic intussusception is observed by using air-contrast enema. Intussusception has been reduced to level of cecum.
Ileocolic intussusception is observed by using bar Ileocolic intussusception is observed by using barium contrast enema. Intussusception has been reduced to level of proximal transverse colon.

Once the diagnosis of intussusception is entertained, surgical personnel should be notified, and an intravenous (IV) line should be placed. The author prefers to have a nasogastric tube in place, though this is not a universal practice. Furthermore, sedation may be helpful while the examination is being conducted.

Preferably, the surgeon should be present in the radiology suite at the time of contrast enema examination. The diagnostic enema is therapeutic in 80-90% of patients. Thus, treatment is usually concluded in the radiology suite, and some surgeons elect to observe these patients in the hospital until they can tolerate an oral diet.

A successful therapeutic reduction must demonstrate free flow of contrast (air or barium series) proximal to the ileocecal valve. Historically, patients in whom enema reduction was unsuccessful were taken immediately to the operating room for laparotomy and manual reduction. However, in patients who are clinically stable, second and third attempts at pneumatic or hydrostatic reduction have proven effective.

Pneumatic reduction is also successful in ileoileal intussusceptions with signs of bowel viability. It should be attempted with caution in patients with jejunojejunal or ileoileal small bowel intussusceptions and in those patients with pathologic lead points or bowel ischaemia. [29]

Technique

A lubricated straight catheter is placed into the rectum and secured by taping the buttocks together tightly. Although many radiologists prefer a balloon-tipped catheter, laceration or perforation of the rectum is a risk with balloon inflation.

A manometer and a blood pressure cuff are connected to the catheter, and air is insufflated slowly to a pressure of 70-80 mm Hg (maximum, 120 mm Hg) and followed fluoroscopically as it percolates proximally through the colon. The column of air stops at the intussusception, and a plain radiograph is taken.

If no intussusception exists or if the reduction is successful, air is observed to pass rapidly into the small bowel. Another radiograph is taken at this point, and the air is allowed to escape before removal of the catheter.

At the completion of the procedure, postreduction radiography (in supine and decubitus/upright views) should be performed to confirm the absence of free air.

Difficult reductions may require several attempts. The use of glucagon (0.5 mg/kg) for facilitating relaxation of the bowel has yielded mixed results and is not routine.

Success rates of 80-90% for pneumatic reduction have been reported. In the stable patient, suggestion of a recurrence following enema reduction necessitates a repeat enema examination.

Ultrasonographically guided hydrostatic reduction

The role of US in the diagnosis of intussusception is well established; however, experience with US-guided hydrostatic reduction of intussusception is limited in the Western hemisphere.

In a 1997 study from Hong Kong, Chan et al compared the efficacy of US-guided versus fluoroscopically guided hydrostatic reduction in 46 patients with intussusception. [30]  The US-guided reduction group had three recurrences (11.5%), one lead point (4.4%), and 19 successful reductions (73%). Only one recurrence (4.2%), one lead point (4.4%), and 12 successful reductions (50%) occurred in the same number of patients undergoing hydrostatic reduction with barium.

No complications occurred in either group, and the accuracy rate of diagnosing a complete reduction was 100% with both forms of reduction. [30]  Hence, the authors concluded that US-guided hydrostatic reduction for childhood ileocolic intussusception is preferred because it is safe, accurate, has a higher success rate, and can avoid radiation exposure risk.

In a 2006 study from China that assessed hydrostatic reduction in 5218 patients, Bai et al reported a 95.5% rate of success and a colonic perforation rate of only 0.17%. [31]  In Europe, successful reduction has been reported in 76-95% of cases, with only one case of perforation in 825 cases. As hydrostatic reduction of intussusception has proved effective in Europe and Asia, it has come into increasing use at some US centers.

Previous
Next:

Histologic Findings

Resected specimens show varying degrees of ischemia, necrosis, or both. Benign reactive lymph node hyperplasia and Peyer patch hyperplasia is common. Resected specimens should be carefully examined for potential lead points (eg, Meckel diverticulum, polyps, lymphoma).

Previous