Acute appendicitis and the role of pre-operative imaging: A cohort study

Acute right iliac fossa (RIF) pain is amongst the most common presentation to the surgical team. Acute appendicitis is the most common cause of this pain and often warrants surgical intervention. In many cases intervention results in a negative appendicectomy with unnecessary complications as a result. The aim of this study was to compare the efficacy of pre-operative imaging in the diagnosis of acute appendicitis to reduce the rate of negative appendicectomy and unnecessary operative intervention.

A retrospective single centre cohort study was undertaken in a district general hospital (DGH) of all laparoscopic appendicectomies over a six-year period. 1344 cases were included and were examined for the use of pre-operative imaging (and type) or none. The sensitivity, specificity, negative and positive predictive value for each type of imaging were analysed for their accuracy in diagnosis appendicitis based on the final histological analysis.

The negative appendicectomy rate was found to be greatest in those undergoing ultrasonography (48.21%) as their method of pre-operative imaging whilst those who underwent computed tomography (CTAP 20.26%) had a lower rate equivalent to that of clinical diagnosis alone (20.73%).

USS is less sensitive than CT in diagnosing acute appendicitis. There is no statistically significant difference in negative appendicectomy rate between clinical diagnosis and CT diagnosis. Pre-operative imaging has a role in the diagnosis of appendicitis but needs to be utilised appropriately to reduce the strain on the surgical department and prevent the potential of a negative appendicectomy.