Clinical features and perforation predictors of appendicitis in infants and toddlers under 3: A retrospective two-center study.

To analyze the clinical characteristics and perforation predictors of appendicitis in infants and toddlers younger than 3 years of age. A retrospective analysis was conducted on the children under 3 years old diagnosed with appendicitis and treated at two centers between March 2018 and May 2024. Based on pathological findings, patients were divided into perforated and non-perforated groups. Further classification was based on the presence or absence of post-appendectomy abscess, resulting in three groups: non-perforated, perforated with post-appendectomy abscess, and perforated without post-appendectomy abscess. Among 72 children with appendicitis, 45 were male (62.5%) and 27 were female (37.5%), with a median age of 31.0 (IQR, 27.0-34.0) months and an average weight of 13.7 ± 2.7 kg. Abdominal ultrasound had a positivity rate of 69.4% (50/72), and 22 patients underwent additional CT scans. All cases were treated with laparoscopic appendectomy, without conversions to open surgery. Perforated appendicitis was diagnosed in 58 cases (80.6%), and non-perforated appendicitis in 14 cases (19.4%). The median symptom duration (48.0 vs. 21.0 h; p < 0.01), CRP levels (70.5 vs. 22.0 mg/L; p < 0.05), and incidence of appendicoliths were significantly higher in the perforated group (p < 0.05). Post-appendectomy abscess was the most common complication, with appendicoliths and prolonged symptom duration being significant risk factors (p < 0.05). The perforated group with post-appendectomy abscess had a significantly longer median hospital stay than the non-perforated group (12.0 vs. 6.0 days; p < 0.01). ROC analysis identified CRP (AUC 0.69, cutoff 34.5 mg/L; p < 0.05) and symptom duration (AUC 0.74, cutoff 35 h; p < 0.01) as predictors of perforation. The high perforation rate of appendicitis in infants and toddlers is associated with prolonged symptoms, elevated CRP, and appendicoliths. Extended symptom duration and appendicoliths increase the risk of post-appendectomy abscesses.