Interloop fluid in intussusception: what is its significance?
Background Sonography has been used to predict pneumatic reduction outcome in children with intussusception.
Objective To assess the prognostic significance of fluid between the intussusceptum and intussuscepiens with respect to reduction outcome,
lead point or necrosis.
Materials and methods Sonograms of children with a discharge diagnosis of intussusception from four institutions were reviewed for interloop fluid
and correlated with results of pneumatic reduction and surgical/pathological findings when available. Maximal dimension of
interloop fluid on a transverse image and fluid complexity were evaluated.
Results Of 166 cases, 36 (21.7%) had interloop fluid. Pneumatic reduction was successful in 21 (58.3%) with fluid and 113 (87.6%)
without. The average largest fluid dimension was 8.7 mm (range 5 mm–19 mm, median 8 mm) in cases with successful reduction
and 12.8 mm (range 4 mm–26 mm, median 12.5 mm) in unsuccessful reduction (p p < 0.0001;odds ratio13:1). In 36 cases with interloop fluid that required surgery, there were four lead points and three necrosis.
In cases without fluid with surgical reduction, there was one lead point and one necrosis. Interloop fluid correlated with
lead point (p p p p = 0.9).
Conclusion Interloop fluid was associated with increased failure of pneumatic reduction and increased likelihood of lead point or necrosis,
particularly when the maximum dimension exceeded 9mm.