The rate of unnecessary appendectomy is frequently criticized. Today, sonography and CT-scan are helpful tools to minimize this rate. Which value has the ultrasonography in the decision making today?
Methods: Retrospective analysis of 132 patients undergoing appendectomy in respect of sonography and rate of histologically confirmed appendicitis from 1.1.95-31.12.98. Prospective analysis of 99 patients admitted for acute appendicitis in respect of pre- and posttest-probability (after sonography) by the responsible surgeon from 1.1.99-31.12.00.
Results: Retrospective part: 122/132 patients had an acute appendicitis (92%). Sonography was performed in 64% of the patients. There was only one wrongly positive sonography. Prospective part: 76/99 patients were operated on. 70/76 had an acute appendicitis (92%). Sonography was performed in 87%. Six patients presented a histologically normal appendix: In two of them no increase of the probability after sonography was noted, in three of them an slight increase of only 20%, and in one of them a decrease of 20% even.
Conclusion: Sonography with a pre- and posttest-probability is recommended in clinically doubtful cases. In our experience the physician performing the sonography is almost always right. But the diagnosis of an acute appendicitis remains a combination of clinical and sonographic evaluation.