Long-term outcomes of microwave endometrial ablation for treatment of patients with menorrhagia: A retrospective cohort study

This study aimed to describe the long-term outcomes of patients with menorrhagia treated with microwave endometrial ablation (frequency, 2.45 GHz), as well as to identify factors associated with recurrence or re-surgery. This retrospective cohort study was conducted from 2007 to 2015 at Shimane University Hospital in Japan. Patients with severe menorrhagia and a desire to preserve their uterus were included in the study. Clinical factors associated with recurrence of menorrhagia or re-surgery were analyzed with a multivariable logistic regression model. Of 160 microwave endometrial ablation candidates, 100 had uterine myomas, 20 adenomyosis, 26 functional excessive menstruation, and 12 endometrial polyps. In the full cohort, age (<40) and uterine cavity length (≥10) were associated with recurrence of menorrhagia and re-surgery. Among patients with myomas, age (<48) and number of myomas (≥4) were associated with recurrence, and largest myoma size (≥5) and preoperative hemoglobin level (<9 mg/dl) were associated with re-surgery. Among subjects with adenomyosis, uterine cavity length (≥10) was associated with recurrence. Microwave endometrial ablation is thought to be a highly efficacious method to control menorrhagia caused by functional bleeding and endometrial polyps. However, microwave endometrial ablation may be less effective for patients younger than 48 years with myomas, especially those with 4 or more myomas, or with a myoma 5 cm or larger in size, and for patients with adenomyosis who have a thickened myometrium. These clinical factors may be useful predictors of success in selecting candidates for microwave endometrial ablation.