When to take it out? Optimal timing of interval appendectomy in 500 consecutive children.

PURPOSE: While interval appendectomy following nonoperative management of perforated appendicitis is delayed until several weeks after presentation, the optimal time from presentation to interval appendectomy is unknown. METHODS: The data warehouse of a large children's hospital was queried for interval appendectomies from 2006 to 2019. Data extracted included demographics, initial and operative hospitalization details, and pathology findings. Student's t-test and logistic regression were used where appropriate. RESULTS: 500 patients were identified with a mean age of 10 years, 53% male. Mean time to operation was 12.7 weeks. Operation prior to 12 weeks was associated with increased odds of acute inflammation on pathology (OR = 2, p < 0.01). Acute inflammation was associated with increased mean operative time (101 vs 84 min, p < 0.01). Presence of an appendicolith, initial hospitalization length, drain placement, readmission prior to operation, age and gender were all non-predictive of acute inflammation. Only 11% of appendices had an occluded lumen and 17% an appendicolith. Carcinoid tumors were identified in 6 patients (1.2%). CONCLUSION: Acute inflammation is found many weeks after perforation and is associated with increased operative time. Acute inflammation is more likely to be present in operations performed prior to 12 weeks.