Pathologic Mechanism of High Frequency Microwave Treatment for Menorrhagia

[Objective]The efficiency and pathologic mechanism of high frequency microwave (9.2GHz) for treatment of menorrhagia, deemed microwave endometrial ablation (MEA) were investigated. [Methods] Forty-four patients with menorrhagia were treated with MEA;13 out of these 44 patients were randomly chosen for complete hysteroscopic examination. The biopsy tissue was taken from the endometrium of these 13 patients. Half of the biopsy tissue was used for histopathological examination and the other half for transmission electron microscope examination. The menstrual situation of the 44 patients was to be followed up for 6-12 months after operation. [Resutls] In 40 out of 44 patients (91.4%), the menstruation status was got improvement and another operation was not needed. The results of histopathological examination showed that the whole endometrium including the basal layer was completely destroyed. The epithelial cells of the basal layer underwent karyopyknosis and karyolysis as well as denaturation of cytoplasmic organella. All these changes were irreversible. However, the superficial muscular layer had not been damaged. [Conclusion] 9.2GHz microwave can destroy the endometrium efficiendy, reaching to basal layer. So, MEA is a safe and efficient operation for treatment of menorrhagia.