Predictors of a histopathologic diagnosis of complicated appendicitis.

BACKGROUND: Despite its utilization, the intraoperative (IO) assessment of complicated appendicitis (CA) is subjective. The histopathologic (HP) diagnosis should be the gold standard in identifying patients with CA; however, it is not immediately available to guide postoperative management. The objective of this study was to identify predictors of an HP diagnosis of CA.

MATERIALS AND METHODS: A retrospective review of all patients who underwent appendectomy at our institution from 2011-2013 was conducted. CA was defined by perforation or abscess on pathology report. Predictors of an HP diagnosis of CA were evaluated using a multivariable regression model.

RESULTS: A total of 239 of 1066 patients had CA based on IO assessment, whereas 143 of 239 patients (60%) had CA on HP and IO assessment. On multivariable analysis, an IO diagnosis of CA was associated with an HP diagnosis of CA (odds ratio [OR]: 10.92; 95% confidence interval [CI]: 7.19-16.58). Other risk factors were age (OR: 1.28; 95% CI: 1.09-1.49), number of days of pain (OR: 1.20; 95% CI: 1.07-1.37), increased heart rate (OR: 1.14; 95% CI: 1.02-1.26), appendix size (OR: 1.09; 95% CI: 1.03-1.16), and an appendicolith (OR: 1.74; 95% CI: 1.12-2.71) on preoperative CT imaging.

CONCLUSIONS: In addition to age, increased heart rate, pain duration, appendix size and appendicolith, the IO assessment is also associated with an HP diagnosis of CA; however, 40% of patients were incorrectly classified. Using these predictors with improved IO grading may achieve more accurate diagnosis of CA.