The impact of evolving management strategies on negative appendicectomy rate

Aim: The management of appendicitis has evolved from the era of open surgery with a negative appendicectomy rate ranging from 20 to 30%. Diagnostic adjuncts such as computed tomography (CT), ultrasound (US) and diagnostic laparoscopy (DL) facilitate refinement of the clinical impression in equivocal cases. The aim of this study was to determine the impact of the increased availability and selective utilization of diagnostic adjuncts on the negative appendicectomy rate. Method: This was a retrospective study of all emergency appendicectomy procedures performed over two 12-month periods encompassing 1996 and 2006. Clinical, radiological, operative and pathological data were analysed. Diagnostic adjuncts were only employed in equivocal cases. Statistical analysis was performed using the chi-squared test. Results: A total of 218 and 171 patients underwent an appendicectomy in 2006 and 1996 respectively. There were 103 men in 1996 and 128 in 2006. There was a significant increase in laparoscopic appendicectomy [131(60%) vs 31 (18%), P > 0.001]. In addition, there was a significant increase in the use of CT (38 vs 1, P < 0.001) and US (39 vs 4, P < 0.001).There was also a significant difference in the use of DL without appendicectomy (39 vs 8, P < 0.001). The negative appendicectomy rate was lower in 2006 (15%. vs 22%, P = 0.13).The perforation rates in both study periods were similar (10%. vs 8%). Conclusion: A policy of selective usage of diagnostic adjuncts only in equivocal cases of appendicitis does not significantly reduce the negative appendicectomy rate.