Histologic findings in hysterectomies after endometrial ablation.

BACKGROUND:Endometrial ablation for abnormal uterine bleeding is used as a less invasive alternative to hysterectomy, however, in cases of treatment failure hysterectomy may be finally performed. The histologic changes in these post-treatment uteri are not well-described. OBJECTIVE:To describe the histological findings in post-endometrial ablation uteri. STUDY DESIGN:During a ten-year period, 321 patients were treated with endometrial ablation. Twenty-five patients (7.8%), 10 treated with NovaSure® and 15 treated with ThermaChoice® endometrial ablation were finally subjected to hysterectomy mostly due to persistent uterine bleeding. Histologic features of these hysterectomies are described. RESULTS:The patients' age ranged from 33 to 73 years (mean 44.5) and 34-53 (mean 42) for the NovaSure® and ThermaChoice® group, respectively. The time from endometrial ablation to hysterectomy was 2-24 months (mean 8.8) and 2-60 months (mean 23.2) for the two groups, respectively (p = 0.01). Hysterectomies performed later (mean 22 months) showed no fibrosis (p = 0.04) compared with those performed earlier (mean 5 months). Endometrial lining was found more frequently in hysterectomies performed later (mean 13 months) than those performed earlier (mean 2 months, p = 0.0004). Abundant necrotic tissue of myometrial origin was found in 28% of the cases, but it was not associated with the time of hysterectomy (p = 0.2). A zonation effect and vascular changes also seen. Granulomatous reaction was not found. Ten patients (40%) harbored adenomyosis and another three (12%) extensive leiomyomas/diffuse leiomyomatosis. CONCLUSION:Necrosis, fibrosis and vascular changes are found during the first year of post-thermal uterine effect. Hysterectomies performed later show less prominent changes and almost normal endometrial lining. Adenomyosis is found in an important part of post-endometrial ablation hysterectomies.