Prospective evaluation of the added value of imaging within the Dutch National Diagnostic Appendicitis Guideline--do we forget our clinical eye?

ABSTRACT

BACKGROUND: Annually 16,000 appendectomies are performed in the Netherlands, of which 15-20% are negative. In 2010, to reduce this unacceptable percentage of superfluous appendectomies, the Dutch Association for Surgery introduced the 'Appendicitis Guideline'. This guideline recommends the use of imaging. In this observational prospective study the added value of imaging in everyday clinical practice is evaluated. METHODS: All patients with suspected appendicitis were included at the emergency department of a Dutch teaching hospital during the period from September 2011 to May 2012 (n = 350; 237 adults and 113 children under 18 years). Adherence to the guideline was evaluated. RESULTS: 75 Patients (21%) were not referred for imaging because of a low suspicion or alternative diagnosis. In 16 patients (5%) the guideline was not followed. Of the 259 patients (74%) who underwent ultrasonography, 105 (30%) also underwent computed tomography (CT). 127 appendectomies were performed, showing appendicitis in 112 patients (88%); 15 appendectomies (12%) were negative. In the latter group, 12 were performed after false positive imaging results, and 3 following inconclusive imaging results. CONCLUSION: When using imaging in the diagnosis of appendicitis, the percentage of negative appendectomies remains close to the percentage declared as unacceptable by the publishers of the guideline.