The Diagnostic Dilemma of Identifying Perforated Appendicitis

BACKGROUND: Despite 61 clinical trials on pediatric appendicitis in the Cochrane database over the last decade, a defined best clinical pathway for acute versus complicated appendicitis remains lacking. The lack of accuracy in the classification of appendicitis can affect the therapeutic course and associated costs since the average cost per case of complicated appendicitis at USD 12,300 which is twice as expensive as uncomplicated appendicitis at USD 6,355 per case1. We hypothesize that the variability in the diagnosis of complicated appendicitis results in a discordance. METHOD: An IRB-approved retrospective review of appendectomies (N=1311) from a 16-month period from 2010 and 2011, excluding interval or incidental appendectomies and including CT imaging, was analyzed for demographics, length of stay (LOS), post-operative antibiotics, and radiological (R), pathologic (P), and operative (O) reports. The classification of appendicitis as "perforated" was compared in a 3-way analysis between radiology (R), pathology (P), and operative reports (O) to identify the incidence of discordance. Classification was compared to LOS, to determine if the diagnosis was consistent with being "acute" (A) 0-48 hours admission or "perforated" (P) >48 hours. RESULTS: 1241 appendectomies met criteria to enter the three study sets: P+O, O+R, and P+R, (N= 1241, 550, and 550, respectively). In study subsets with radiology (P+R and O+R), 47% had a CT with a definite radiologic diagnosis in 44%. The discordance in diagnosis in P+O, P+R, O+R was 11%, 15.7% and 16.6%, respectively. Pathology and operative reports had the most consistent diagnoses with a concordance of 89%. The O+R group had 16.6% discordance, of which 35% of cases were intraoperatively determined to be perforated, but actually 38.9% of those cases had a LOS <48hrs, consistent with being acute nonperforated. The LOS in the >48 hours group was nontrivial with a median of 88 hours (range 50-272). CONCLUSION: There is a substantial discrepancy between operative, radiologic, and pathologic reports with the greatest discordance occurring between radiologic and operative diagnoses. The variation in the LOS confirms this discordance. Although, the diagnostic classification of complicated and uncomplicated appendicitis are not standardized which contributes to the discordance, the consequences are substantial in terms of medical costs and patient length of stay. Standardizing the criteria for the classification of the type of appendicitis across specialties may improve diagnostic accuracy needed for meaningful clinical trials and to identify best practices for optimal use of hospital resources and health care costs that continue to be elusive.