Identification of Children With a Positive Ultrasound and Appendicitis Using the Pediatric Appendicitis Risk...

Area of Science:

• Pediatric Surgery
• Diagnostic Imaging
• Clinical Decision Support

Background:

• False positive ultrasounds (US) for pediatric appendicitis occur in up to 10% of cases, impacting the negative appendectomy rate.
• Minimizing negative appendectomies is a critical quality indicator in pediatric surgery, with a benchmark of less than 2%.
• The Pediatric Appendicitis Risk Calculator (pARC) score stratifies appendicitis risk but requires integration with imaging for optimal surgical candidate selection.

Purpose of the Study:

• To determine the proportion of children with suspected appendicitis, a positive US, and a medium-high pARC score (≥25%) who have confirmed appendicitis.
• To evaluate the utility of combining pARC risk stratification with positive US findings in identifying optimal surgical candidates.
• To test the hypothesis that the proportion of appendicitis in this cohort would be 98% (95% CI ≥96%).

Main Methods:

• A retrospective cohort study included 327 children aged 4-17 years with suspected appendicitis and positive US findings.
• Demographic, clinical, and imaging data were abstracted, and the pARC score was calculated using its established formula.
• Appendicitis was confirmed by pathology; non-operated patients underwent follow-up to rule out missed cases.

Main Results:

• Of 327 patients with positive US, 294 (89.9%) had appendicitis. A pARC score ≥25% was assigned to 259 patients (79.2%).
• Among those with a pARC score ≥25%, 255 (98.5%) had confirmed appendicitis (95% CI 96.1-99.6), significantly higher than the 57.3% in those with pARC <25% (p<0.0001).
• The combination of pARC ≥25% and positive US demonstrated a positive predictive value of 98.5% and sensitivity of 86.7% for appendicitis.

Conclusions:

• A positive US combined with a pARC score of 25% or higher in children with suspected appendicitis yields a very high probability of confirmed appendicitis.
• This combined approach effectively identifies children who are optimal surgical candidates.
• Children with lower pARC scores may benefit from clinical re-evaluation or further diagnostic imaging to avoid unnecessary surgery.