Clinical and ultrasound correlation in the diagnosis of acute appendicitis: a retrospective study

Introduction

Ultrasonography (USG) has been increasingly used to help in the diagnosis of acute appendicitis with the aim of minimizing both underdiagnosis and overdiagnosis of acute appendicitis. The aim of this study is to ascertain whether USG could change the decision making in the management of acute appendicitis.

Methods

This is a retrospective analysis of prospective data on 100 patients who underwent appendicectomy either open or laparoscopic. These 100 patients were divided into two groups; those with equivocal appendicitis and those with strongly suspected appendicitis based on clinical assessment. Modified Alvarado Score (MAS) was used for clinical assessment.

All of them had USG as the sole mode of imaging. The accuracy of each mode of assessment was confirmed by macroscopic and/or microscopic appearance of the appendix. Based on the findings it was judged whether performing USG has made any changes to the clinical decision.

Results

There were 61 males and 39 females with a mean age of 25 (7-86) years. Total number of patients admitted with modified Alvarado score (MAS) of 2-6 was 39 and those with MAS of 7-9 was 61. True positive cases of acute appendicitis in the former group were 33. While ultrasonography detected acute appendicitis correctly in 30 patients, only 3 patients were correctly diagnosed clinically. Out of 59 true positive cases of acute appendicitis in the latter group, USG detected only 41 cases whereas all 59 patients were correctly identified clinically. While USG has helped change the clinical decision in the equivocal appendicitis, clinical decision takes precedence over USG in patients with typical appendicitis.

Conclusion

While USG has definite place in the evaluation of suspected appendicitis with low clinical probability, it has little value in changing the clinical decision to undertake appendicectomy in patients getting admitted with typical history of appendicitis.

The Sri Lanka Journal of Surgery 2015; 33(2): 8-13