Air enema reduction is performed to treat intussusception, a common cause of bowel obstruction in children. Researchers at Texas Children’s Hospital in Houston conducted a study of its safety and efficacy, with and without a rectal balloon. They reported their findings in a May 24th online article in Pediatric Radiology.
Preventing an air leak is essential, according to the authors, because successful reduction depends on establishing an intracolonic pressure gradient sufficient to move the intussusceptum out of the intussuscipiens. A variety of methods are used to maintain an anal seal. These include manual compression across the buttocks, tight taping of the buttocks, and using an external occlusion disc or a Foley-type catheter balloon inflated within the rectum.
The authors evaluated 566 cases of intussusception performed at Texas Children’s Hospital over an 8-year period between 2008 through 2015. The pediatric patients ranged from 2-months to 14 years, with 98% under 5 years and 43% under 12 months.
A rectal balloon was used in 292 reduction attempts, or 52% of the total. The authors analyzed patients’ gender and age, reduction success, bowel perforation, reduction with or without bowel resection, and presence and sites of bowel necrosis or perforation and lead point. Experience levels of the 39 pediatric imaging practitioners who performed the reductions were also analyzed. All data was evaluated with respect to three outcomes: failed reduction, perforation, and bowel resection. The authors calculated risk factors for bowel perforation and predictors of successful reduction.
Lead author Christopher I. Cassady, MD, of the Edward B. Singleton Department of Pediatric Radiology, and colleagues reported successful outcomes for 93% of patients with balloon use and 89% without. Nine percent of patients, all under 9 months, had failed reductions and required surgery. These included 21 failures with eight perforations from the group in which a balloon was used, and 30 failures with one perforation in the group in which a balloon was not used. All perforations occurred in patients under 9 months of age.
The authors speculated that failures may have occurred because “the thinner colonic wall in younger children results in greater wall tension for a given intraluminal pressure and tube radius ... in which wall tension is proportional to the pressure and radius and inversely proportion to the wall thickness.” They suggested that “less aggressive attempts at air enema reduction might be warranted in younger infants, realizing that although an unsuccessful air enema reduction translates into a surgery, the intraoperative reduction might be less likely to necessitate a hemicolectomy or other bowel resection.”
The authors identified three significant associations with bowel perforation. These included rectal balloon use, patients younger than one year, and physicians who had five years’ experience or less performing the procedure. They wrote that perforation, failure, and balloon use was associated with infants to 12-month olds. Patients over 10 months had a near-zero risk of perforation. In fact, bowel perforation occurred in only 1.6% of cases over eight years.
The use of a rectal balloon benefitted older children, with the failure rate dropping to near zero by 30 months of age, compared to a static failure rate of between 3% and 12% when not using a balloon. No anorectal complications occurred in any cases with the use of a balloon.
While the authors were able to associate a trend of physician experience with reduction failure or bowel resection, they were not able to demonstrate statistically significant differences in reduction failure or bowel resection based on this factor. They also recommended that a prospective randomized study of intussusception reduction with and without rectal balloon inflation to further determine the best technique.
Balloon use in air enema reduction for pediatric intussusception. Appl Radiol.