Negative Appendicectomy Rates in Females of Childbearing Age: A Retrospective Analysis and Literature Review.

Introduction A negative appendicectomy rate (NAR) is defined as the portion of pathologically normal appendices removed surgically in patients suspected of having acute appendicitis. The lifetime risk of acute appendicitis is 8.6% for males and 6.7% for females; contrarily, the lifetime risk of appendicectomy is 12% for males and 23.1% for females. This study aims primarily to evaluate the true NAR in females of childbearing age to offer insight into potential strategies to reduce the number of unnecessary operative procedures carried out, along with their associated morbidity and mortality. Methods All emergency appendicectomies over a one-year period were retrospectively identified and collected from a single tertiary care centre. Preoperative clinical, laboratory and postoperative histopathological data were collected. The negative appendicectomy rate in subgroups divided by biomarkers and radiological imaging findings were analysed. The diagnostic value of these modalities in the context of acute appendicitis was found by calculating the sensitivity, specificity, positive predictive values, and negative predictive values. Results A total of 417 patients were included (median age 26; M:F, 0.7:1.0). The overall negative appendicectomy rate was 35.0% (146/417). Two-hundred sixty-one patients underwent an appendicectomy in the child-bearing age group. The NAR was significantly higher in those females with raised WBC and C-reactive protein (CRP) compared to their male counterparts (p-value -<0.001). Conclusion Women of childbearing age have a higher NAR of 43% when compared to the general population of 35%. Preoperative tests, including ultrasound scans, computed tomography and inflammatory markers in blood tests, help direct those who would benefit from surgery to the operating theatre, however, no test alone is suitably sensitive or specific. To reduce the NAR, management options include a return to observation and serial examination, increased use of low-dose CT or a commitment to improving the performance of ultrasonography.