Measuring Anatomic Severity in Pediatric Appendicitis: Validation of the American Association for the Surgery of Trauma Appendicitis Severity Grade

Objective To assess whether the American Association for the Surgery of Trauma (AAST) grading system accurately corresponds with appendicitis outcomes in a US pediatric population. Study design This single-institution retrospective review included patients < 18 years of age (n = 331) who underwent appendectomy for acute appendicitis from 2008 to 2012. Demographic, clinical, procedural, and follow-up data (primary outcome was measured as Clavien-Dindo grade of complication severity) were abstracted. AAST grades were generated based on intraoperative findings. Summary, univariate, and multivariable regression analyses were performed to compare AAST grade and outcomes. Results Overall, 331 patients (46% female) were identified with a median age of 12 (IQR, 8-15) years. Appendectomy was laparoscopic in 90% and open in 10%. AAST grades included: Normal (n = 13, 4%), I (n = 152, 46%), II (n = 90, 27%), III (n = 43, 13%), IV (n = 24 7.3%), and V (n = 9 2.7%). Increased AAST grade was associated with increased Clavien-Dindo severity, P = .001. The overall complication rate was 13.6% and was comprised by superficial surgical site infection (n = 13, 3.9%), organ space infection (n = 15, 4.5%), and readmission (n = 17, 5.1%). Median duration of stay increased with AAST grade (P < .0001). Nominal logistic regression identified the following as predictors of any complication (P < .05): AAST grade and febrile temperature at admission. Conclusions The AAST appendicitis grading system is valid in a single-institution pediatric population. Increasing AAST grade incrementally corresponds with patient outcomes including increased risk of complications and severity of complications. Determination of the generalizability of this grading system is required.