Introduction: Acute appendicitis is the most frequent pediatric surgical emergency. 30% to 75% of patients present with complicated appendicitis at the time of surgery (1), increasing the frequency of intra-abdominal abscess (IAA), between 14% to 20% of this population (2), which represents an important cause of morbidity and mortality. Methods: A case-control study (1:4 ratio) was conducted in a third-level pediatric hospital in Bogota (Colombia), our aim was to establish the associated factors for the presentation of IAA after appendectomy for complicated appendicitis in patients under the age of 18. Results: A cohort of 545 patients (109 cases: perforated appendectomy with intra abdominal abscess and 436 controls: perforated appendicitis with no intra abdominal abscess) was included in this study, mostly males 53.76% and laparoscopic approach 79.45% (median: 11 years). There was no significant difference for post appendectomy IAA between laparoscopic and open procedures: adjusted OR 1,33 (IC 95%: 0,67 – 2,60 y p=0.4). Using the model of logistic regression, some factors were identified as being associated with the presentation of post appendectomy IAA: such as children under the age of 10, tachycardia adjusted to age and fever on admission to the emergency department, abdominal pain duration (per hour), intraoperative time and surgical findings (95% confidence interval, p <0.05). Conclusion: It is necessary to guarantee an early diagnosis of complicated appendicitis, to prevent this postoperative complication. And identify the possible factors associated with IAA post-appendectomy, in order to stratify high-risk groups to make the diagnosis early, providing adequate and timely treatment, reducing the morbidity and mortality associated with this complication, our results being a useful tool for this purpose.
