Magnetic resonance imaging reduces the rate of unnecessary operations in pregnant patients with suspected acute appendicitis: a retrospective study.

PURPOSE

This is a retrospective single-institution study performed to compare the rate of unnecessary operations in pregnant women with suspected acute appendicitis with and without the use of MRI.

METHODS

The study subjects were all pregnant women with suspected acute appendicitis admitted to a tertiary institution from January 2012 to December 2019. If acute appendicitis was not excluded clinically and by ultrasound (US), laparoscopies were performed until May 2017 (US-only group). MRI was added as a diagnostic tool when US was inconclusive from May 2017 (US + MRI group). Surgery was considered unnecessary when no inflamed appendix was found. The rate of unnecessary surgery, postoperative complications, length of stay were analyzed.

RESULTS

Seventy-six women were included in the study; 38 women in the US-only group and 38 women in the US + MRI group. There were no differences in admission characteristics between the groups. One of 38 women (2.6%) underwent unnecessary surgery in the US + MRI group 10 of 38 (26.3%) in the US-only group (P = 0.007). The patients in the US + MRI group were significantly less likely to undergo a diagnostic operation than in the US-only group (5.26% 55.3%, respectively; P < 0.001) and their hospital stay was significantly shorter (0.74 ± 1.64 days 3.7 ± 3.0 days, respectively; P < 0.001). The obstetric outcomes were not different between the groups. MRI had a sensitivity of 83.3% and specificity of 100% in the series.

CONCLUSION

The rate of unnecessary surgery was significantly reduced in pregnant women, who underwent MRI after inconclusive transabdominal US.