Association of Gangrenous, Suppurative, and Exudative Appendicitis with Postoperative Outcomes and Resource Utilization in Children with Appendicitis: Implications for a Revised Definition of Complicated Appendicitis

Background: Controversy exists whether the presence of gangrenous, suppurative, and/or exudative appendicitis increases the risk for adverse outcomes in children with non-perforated appendicitis. The goal of this study was to evaluate whether these findings influence risk of surgical site infections (SSI) and resource utilization in a large multicenter cohort of children.

Methods: We conducted a retrospective analysis of children undergoing appendectomy for acute appendicitis from January 1, 2015 to December 31, 2020 using pooled NSQIP-Pediatric data from 11 hospitals participating in the Eastern Pediatric Surgical Network research consortium. Operative reports were obtained for all cases and reviewed by 18 surgeons for gangrene/necrosis, suppuration, or exudate (“GSE”) directly involving the appendix using standardized definitions and video-based review instructions. Patients with evidence of perforation by NSQIP-Pediatric criteria were excluded. Outcomes included rates of SSI (incisional or organ space), any postoperative abdominal imaging, and mean postoperative length of stay (LOS). Multivariable regression was used to estimate the effect of GSE findings on outcomes after adjusting for patient characteristics and hospital-level effect. Inter-rater agreement among reviewers for identifying the presence or absence of GSE findings was assessed with the Kappa statistic.

Results: 5002 children without evidence of perforated disease by NSQIP-Pediatric criteria were included, of which 14.5% (726) had a GSE finding. Agreement was substantial among reviewers for classifying cases with GSE (Kappa 0.78 [95%CI 0.72, 0.85]). In unadjusted analyses, the presence of GSE findings were associated with higher rates of SSI (2.8% versus 1.7%, p=0.05), any postoperative imaging (5.9% versus 3.6%, p<0.01) and increased mean postoperative LOS (1.6 days versus 0.9 days, p<0.0001). In adjusted analyses, GSE findings remained associated with significantly higher rates of SSI, postoperative imaging, and postoperative LOS (Table). In a stratified analysis, the absence of gangrenous changes did not mitigate the influence of suppuration or exudate on the outcomes (Table).

Conclusion: In children with non-perforated appendicitis, presence of gangrenous, suppurative, and exudative changes are associated with increased rates of SSI, use of postoperative imaging, and postoperative length of stay. Although absolute differences in outcomes are modest, these findings may have important implications for refining optimal antibiotic management, clinical research reporting, and severity adjustment in comparative performance reporting (e.g., NSQIP-Pediatric).