Risk factors for recurrent endometriosis after conservative surgery in a quaternary care center in southern Thailand

Objectives To determine the 2-year recurrence rate of endometriosis after conservative surgery and the risk factors for recurrence. Methods This study retrospectively analyzed women with endometriosis who underwent conservative surgery and had at least a 2-year follow-up at a quaternary care hospital in southern Thailand from January 2000 to December 2019. Recurrent endometriosis was defined as either presence of endometrioma with a diameter ≥ 2 cm for more than three consecutive menstrual cycles or relapse of pelvic pain with the same or higher visual analog scale (VAS) score as before surgery. Multivariate logistic regression analysis was used to identify the risk factors for recurrence. Results The median (interquartile range [IQR]) age was 34 (29, 38) years in 362 cases and nearly three-quarters (74.2%) were nulliparous. Cyclic pain was the most common clinical presentation (48.9%) and the median (IQR) VAS score of pelvic pain was 6 (5, 9). Ovarian cystectomy was the most common procedure (68.1%). The 2-year recurrent endometriosis rate after conservative surgery was 23.2%, and the overall recurrence rate was 56.4%. The risk factors of recurrence were preoperative moderate to severe pelvic pain (adjusted odds ratio [aOR] 1.93; 95% confidence interval [CI], 1.12–3.34; p = 0.017), adhesiolysis/ablation/ovarian cystectomy without unilateral oophorectomy (aOR 2.71; 95% CI, 1.40–5.23; p = 0.002), and duration of postoperative hormonal treatment < 24 months (aOR 10.58; 95% CI, 5.47–20.47; p < 0.001). Conclusion The 2-year recurrence rate after conservative surgery for endometriosis was 23.2%. Preoperative moderate to severe pelvic pain, procedures except unilateral oophorectomy, and postoperative hormonal treatment < 24 months were risk factors for recurrence.