Determinants of postoperative abscess occurrence and percutaneous drainage in children with perforated appendicitis.

PURPOSE: Postoperative abscesses after perforated appendicitis have no clear risk factors or indications for percutaneous drainage. Our study addressed these two issues.

METHODS: A logistic regression model was used to delineate risk factors for postoperative abscess in children with perforated appendicitis treated during a recent 5-year period. Drainage of abscess was compared to antibiotic treatment.

RESULTS: Postoperative abscess occurred in 42 (14.8%) of 284 patients. Higher WBC count, presence of bowel obstruction at presentation, diffuse peritonitis with a dominant abscess at surgery, and one specific surgeon were significantly associated with postoperative abscess, while fever or pain requiring narcotics at the time of abscess diagnosis was significantly associated with drainage. Compared to non-drainage, those drained had longer hospital stay including readmissions (15.9 ± 5.3 vs. 12.2 ± 4.6 days, p < 0.005) and less readmissions (9.5 vs. 33.3%, p = 0.06). Over the 5-year period, there was no increased trend in abscess occurrence (p = 0.56), but there was an increased trend in the use of percutaneous drainage (p = 0.02).

CONCLUSIONS: The risk of a postoperative abscess can be predicted by specific clinical characteristics, surgical findings, and treatment-related factors. Percutaneous drainage was associated with longer hospital stays, but less readmissions.