Recurrence, Reoperation, Pregnancy Rates, and Risk Factors for Recurrence after Ovarian Endometrioma Surgery: Long-Term Follow-Up of 756 Women

PURPOSE: The aims of this study were to evaluate the cumulative recurrence, reoperation, and pregnancy rates after ovarian endometrioma surgery at a single institution for more than a 5-year follow-up period. MATERIALS AND METHODS: This study was conducted as a retrospective chart review of patients with ovarian endometrioma who underwent surgery between January 2008 and March 2016. Study subjects included premenopausal women with at least 5 years of follow-up. Exclusion criteria were patients with stage I or II ovarian endometrioma, those who underwent hysterectomy or bilateral oophorectomy, and presence of residual ovarian lesions on the first postoperative ultrasonography at 3-6 months. Recurrence was defined as a cystic mass by ultrasonography. RESULTS: A total of 756 patients were recruited. The median follow-up duration was 85.5 months (interquartile range, 71-107 months). Recurrent endometrioma was detected in 27.9% patients, and reoperation was performed in 8.3% patients. Cumulative rates at 24, 36, 60, and 120 months were 5.8%, 8.7%, 15.5% and 37.6%, respectively, for recurrence and 0.1%, 0.5%, 2.9%, and 15.1%, respectively, for reoperation. After multivariable analysis, age ≤31 years [hazard ratio (HR)=2.108; 95% confidence interval (CI)=1.522-2.921; p<0.001], no subsequent pregnancy (HR=1.851; 95% CI=1.309-2.617; p<0.001), and postoperative hormonal treatment ≤15 months (HR=2.869; 95% CI=2.088-3.941; p<0.001) were significant risk factors for recurrent endometrioma. Among 315 patients who desired pregnancy, 54.0% were able to have a successful pregnancy and delivery. CONCLUSION: Considering that longer postoperative hormonal treatment is the sole modifiable factor for recurrent endometrioma, we recommend long-term hormonal treatment until subsequent pregnancy, especially in younger women.