Acute appendicitis: Effect of increased use of CT on selecting patients earlier

PURPOSE: To explore the possibility of a relationship between increased use of computed tomography (CT) for diagnosis of appendicitis and increased occurrence of minimal or subtle CT and surgical findings. MATERIALS AND METHODS: Two groups, each with 50 consecutive patients who underwent CT before appendectomy in 1997 and 2000, were compared. CT scans and surgery-pathology reports were evaluated on a six-grade scale from normal to abscess or inflammatory mass. The demographics, surgical techniques, hospital stay, and grade distribution for the two groups were compared, and the CT results were correlated with surgical findings. RESULTS: In 1997, CT was performed in 33% (50 of 152) of patients undergoing appendectomy, as compared with 59% (50 of 85) 3 years later (P < .001). There was excellent correlation between surgical-pathologic and CT grades (weighted K, 0.75; P < .001; Spearman rank correlation, 0.83). There was no significant difference in demographics, rate of surgery or surgical techniques used, but there was a significant decrease in the median surgical-pathologic grades, from 3.0 to 2.5 (P = .05) for all patients and from 3.5 to 2.6 (P = .003) for patients who underwent CT. Similarly, the median CT grade decreased from 4 to 3 (P < .001). Seven patients had subtle CT findings in 1997 compared with 16 in 2000 (P = .004), and there was a significant decrease in mean hospital stay, from 2.8 days +/- 4 (SD) to 1.5 days +/- 2 (P = .008). CONCLUSION: With increased CT use, there were less severe imaging findings, including absence of periappendiceal stranding, and a significant decrease in surgical-pathologic severity of appendiceal disease and hospital stay. (C) RSNA, 2002.