Effect of cross-sectional imaging on negative appendectomy and perforationrates in children

PURPOSE: To compare negative appendectomy and perforation rates in children who underwent ultrasonography (US), computed tomography (CT), or no imagin g before urgent appendectomy. MATERIALS AMD METHODS: All children who underwent urgent appendectomy durin g a 4 1/2-year period were identified in a surgical billing database. Patho logy reports were coded as negative or as showing acute inflammation or per foration. Imaging up to 14 days before appendectomy or abscess drainage was noted, and imaging-based diagnoses were compared with pathologic findings. Patient age and sex were recorded. RESULTS: Two hundred ninety-nine children, 176 (59%) male and 123 (41%) fem ale (mean age, 10.4 years; age range, 1-21 years), underwent urgent appende ctomy. One hundred twenty-six (42%) underwent no imaging, 121 (41%) underwe nt US with or without CT, and 52 (17%) underwent CT only; 44 (15%) underwen t both US and CT. There were significantly higher rates of appendectomy wit h normal pathologic findings ("negative appendectomy") in patients who unde rwent no imaging (14% [18% of 126]) or US (17% [20 of 121]) versus the rate s in those who underwent CT only (2% [One of 52]) P =.02 and P =.007, respe ctively). The negative appendectomy rate was 7% in 96 patients who underwen t CT with or without prior US. The perforation rates were not significantly different. CONCLUSION: As compared with children who underwent no preoperative imaging and those who underwent US, children who underwent CT had a significantly lower negative appendectomy rate, without a significantly higher perforatio n rate.