Exploratory Analysis of Factors Associated with Conversion After Initially Attempted Laparoscopic Appendectomy in Children: The Role of Inflammatory Markers and Clinical Scores

Background: Acute appendicitis is the leading pediatric surgical emergency. Identifying drivers of disease severity and laparoscopic-to-open conversion remains critical for surgical planning. We evaluated the discriminative performance of clinical scores and inflammatory biomarkers for both peritonitis and surgical conversion, and explored combined clinical–laboratory models among children with acute appendicitis undergoing an initially attempted laparoscopic appendectomy. Methods: A retrospective study was conducted, including pediatric patients with acute appendicitis who underwent surgical treatment. Clinical scores (Alvarado score and Pediatric Appendicitis Score) and laboratory parameters (C-reactive protein, neutrophil count, and neutrophil-to-lymphocyte ratio) were analyzed. Receiver operating characteristic (ROC) curve analysis was used to assess discriminative ability, with calculation of the area under the curve (AUC). Combined models based on standardized variables were constructed and evaluated. Comparisons between AUCs were performed using DeLong’s test. Results: For prediction of peritonitis, clinical scores suggested good discriminative ability within the sample, with AUC values of 0.805 for the Alvarado score and 0.812 for the Pediatric Appendicitis Score, whereas C-reactive protein showed moderate performance (AUC = 0.735). Combined models achieved AUC values of 0.823 for both zPAS + zCRP and zAlvarado + zCRP, and 0.773 for zCRP + zNLR. For surgical conversion, higher within-sample AUC values were observed, reaching 0.879 for the Alvarado score and up to 0.932 for the combined models (zAlvarado + zCRP), followed by 0.926 for zPAS + zCRP and 0.874 for zCRP + zNLR. However, these results should be interpreted with caution due to the limited number of conversion events. Conclusions: Clinical scoring systems and inflammatory biomarkers suggested good ability to predict peritonitis in pediatric acute appendicitis, while their performance for predicting surgical conversion appeared higher but remains exploratory. Combined clinical–laboratory models showed promising within-sample discriminative ability; however, given the very small number of conversion events, these findings should be regarded as exploratory and hypothesis-generating only.