Effects of thermal endometrial ablation. Clinicopathologic correlations.

Electrothermal ablation of endometrium was performed on 207 women for abnormal and sometimes painful uterine bleeding. Recurrence of symptoms or inadequacy of treatment led to hysterectomy in 33 women at intervals of 2 weeks to 60 months. Patterns of uterine tissue destruction, healing and repair, and endometrial regeneration were correlated with the postablation interval. The endometrial thickness was completely destroyed. Necrosis dominated the first month, and a chronic repair-regeneration phase followed. Foreign body giant cells reacted with necrotic eschar, remnants of which were present to 47 months. Intact endometrium regenerated focally in 10 uteri and diffusely in 5. Indications for hysterectomy were attributed directly to ablation failure in 18 of 33 cases. Familiarity with the morphologic effects of ablation will aid in relating ablation failures to direct mechanisms, complications of the procedure, or unrelated events.