Refining sonographic criteria for paediatric appendicitis: combined effects of age-based appendiceal size and secondary findings

Abstract

ObjectiveAppendiceal diameter is a primary sonographic determinant of paediatric appendicitis. We sought to determine if the diagnostic performance of outer appendiceal diameter differs based on age or with the addition of secondary sonographic findings.MethodsWe retrospectively reviewed patients aged less than 19 years who presented to the Boston Children’s Hospital ED and had an ultrasound (US) for the evaluation of appendicitis between November 2015 and October 2018. Our primary outcome was the presence of appendicitis. We analysed the cases to evaluate the optimal outer appendiceal diameter as a predictor for appendicitis stratified by age (<6, 6 to <11, 11 to <19 years), and with the addition of one or more secondary sonographic findings.ResultsOverall, 945 patients met criteria for inclusion, of which 43.9% had appendicitis. Overall, appendiceal diameter as a continuous measure demonstrated excellent test performance across all age groups (area under the curve (AUC) >0.95) but was most predictive of appendicitis in the youngest age group (AUC=0.99 (0.98–1.00)). Although there was no significant difference in optimal diameter threshold between age groups, both 7- and 8-mm thresholds were more predictive than 6 mm across all groups (p<0.001). The addition of individual (particularly appendicolith or echogenic fat) or combinations of secondary sonographic findings increased the diagnostic value for appendicitis above diameter alone.ConclusionsAppendiceal diameter as a continuous measure was more predictive of appendicitis in the youngest group. Across all age groups, the optimal diameter threshold was 7 mm for the diagnosis of paediatric appendicitis. The addition of individual or combination secondary sonographic findings increases diagnostic performance.

The BIDIAP index: a clinical, analytical and ultrasonographic score for the diagnosis of acute appendicitis in children

“…Our results agree with previous studies that reported that the appendiceal caliber was a strong predictor of PAA [ 21 ].…”

Serum neutrophil gelatinase-associated lipocalin (NGAL) as a diagnostic tool in pediatric acute appendicitis: a prospective validation study

“…In relation to radiological studies for the diagnosis of PAA, abdominal ultrasound (AUS) has an excellent diagnostic yield [ 6 ], especially when combined with clinical and analytical scores (such as PAS score or Alvarado score) [ 1 ]. However, AUS is an operator-dependent test and visualization of the appendix is not achieved in all patients, so it cannot be considered a definitive diagnostic test [ 6 , 7 ].…”

“…In relation to radiological studies for the diagnosis of PAA, abdominal ultrasound (AUS) has an excellent diagnostic yield [ 6 ], especially when combined with clinical and analytical scores (such as PAS score or Alvarado score) [ 1 ]. However, AUS is an operator-dependent test and visualization of the appendix is not achieved in all patients, so it cannot be considered a definitive diagnostic test [ 6 , 7 ]. It should be noted that the use of computed tomography (CT) in the setting of PAA is limited due to the significant radiation dose associated with this particularly vulnerable population.…”

Non-operative treatment of acute appendicitis in children: clinical efficacy of amoxicillin-clavulanic acid in a retrospective single-centre study

“…Across all age groups, the optimal appendiceal diameter threshold is 7 mm for the diagnosis of paediatric appendicitis. 27 Inclusion criteria included all the following: (1) Imaging-confirmed uncomplicated appendicitis by ultrasound or CT: increase in the calibre of the appendix, measured at more than 6 mm in diameter with non-compressibility, localised free fluid, increased echogenicity of periappendiceal fat; (2) Age 5–15 years; (3) Non-septic clinical aspect (good general condition, normal haemodynamic status, normal diuresis); (4) Intravenous and oral antibiotic regimen by amoxicillin-clavulanic acid; (5) Parental good understanding of the monitoring instructions. Exclusion criteria included any of the following: (1) Ultrasound or CT scan showing one or several stercoliths, an abscess, appendicular mass or generalised peritonitis; (2) Primary or secondary immune deficiency; (3) Parental refusal of research protocol; (4) Impossibility of home follow-up after discharge from hospital; (5) Allergy to penicillin.…”