Is acute appendicitis still misdiagnosed?

The optimal diagnostics and treatment of acute appendicitis continues to be a challenge. A false positive diagnosis of appendicitis may lead to an unnecessary operation, which has been appropriately termed negative appendectomy. The aim of our study was to identify the effectiveness of preoperative investigations in preventing negative appendectomy.

A retrospective study was performed on adult patients who underwent operation for suspected acute appendicitis from 2008 to 2013 at Vilnius University Hospital Santariskiu Klinikos. Patients were divided into two groups: group A underwent an operation, where appendix was found to be normal (non-inflamed); group B underwent an appendectomy for inflamed appendix. Groups were compared for preoperative data, investigations, treatment results and pathology findings.

554 patients were included in the study. Preoperative laboratory tests results of hemoglobin, hematocrit concentrations and white blood cell count were significantly higher in group B (p<0.001). Ultrasonography was performed for 78 % of patients in group A and 74 % in group B and did not provide any statistically significant results. Comparing Alvarado score results, there were more patients with Alvarado score less than 7 in group A than in group B. In our large series we could find only four independent risk factors, and they could only account for 24 % of cases.

In summary, acute appendicitis is still often misdiagnosed and the ratio of negative appendectomies remains rather high. Additional investigations such as observation and computed tomography should be used to prevent this.