Long-term follow-up of endometriosis surgery in Ontario: a population-based cohort study

BACKGROUND: Endometriosis is a chronic gynecological disease affecting approximately 10% of reproductive aged females and leads to decreased quality of life and productivity. Despite effective medical options, many women do require surgery for endometriosis. There is limited literature examining long term outcomes of endometriosis surgery. OBJECTIVE: This study aimed to characterize the long-term outcomes, including recurrence of symptoms, fertility outcomes, and need for reoperation, of patients who underwent surgical management for endometriosis. STUDY DESIGN: This was a population-based cohort study in which the universal coverage health database for the province of Ontario, Canada, was used to identify women aged 18 to 50 years who underwent surgery for endometriosis from April 1, 2002, through March 31, 2018. Surgery was classified as diagnostic laparoscopy, conservative or uterine preserving (minor or major, with and without ovarian preservation), or hysterectomy (with and without ovarian preservation). The outcomes were evaluated from 30 days after the index surgery to the end of the study period or at censoring. Cox proportional hazard regression models were used to estimate the hazard ratios between exposures and outcomes following adjustment for confounders. RESULTS: A total of 84,885 women 2,718 (3.2%) diagnostic laparoscopy, 21,594 (25.4%) minor conservative surgery, 28,484 (33.6%); major conservative with ovarian preservation, 2,102 (2.5%) major conservative without ovarian preservation, 21,609 (25.5%) hysterectomy with ovarian preservation, and 8,378 (9.9%) hysterectomy without ovarian preservation) were included in the cohort and followed for a median of 10 years (interquartile range, 6-13 years). In the first post-operative year, women who underwent diagnostic laparoscopy were significantly more likely to require repeat surgery (adjusted hazard ratio, 1.68; 95% confidence interval, 1.51-1.87), whereas those who underwent major conservative surgery were significantly less likely to require repeat surgery (with ovarian preservation: adjusted hazard ratio, 0.44; 95% confidence interval, 0.41-0.48; without ovarian preservation: adjusted hazard ratio, 0.05; 95% confidence interval, 0.03-0.09). Among women who did not receive repeat surgery in the first year, those who underwent a diagnostic laparoscopy (adjusted hazard ratio, 0.85; 95% confidence interval, 0.76-0.95) and major conservative surgery without ovarian preservation were less likely to undergo repeat surgery (adjusted hazard ratio, 0.12; 95% confidence interval, 0.09-0.18) than those who initially had minor surgery. Compared with those who initially underwent minor surgery, patients who underwent other treatment modalities were less likely to undergo a hysterectomy (diagnostic laparoscopy: adjusted hazard ratio, 0.85; 95% confidence interval, 0.75-0.96; major surgery with ovarian preservation: adjusted hazard ratio, 0.60; 95% confidence interval, 0.57-0.64; major surgery without ovarian preservation: adjusted hazard ratio, 0.05; 95% confidence inerval, 0.03-0.08). Following minor and major conservative with ovarian preservation surgery, 8,331 (38.6%) and 9,498 (33.3%) of patients sought an infertility consult within 1 year, respectively. By 5 years after the index surgery, 5,290 (29.4%) of patients who had minor conservative surgery and 4,528 (20.7%) of those who had major conservative with ovarian preservation surgery had given birth at least once. CONCLUSION: Our study suggests that only a few endometriosis patients who undergo hysterectomy surgery require repeat surgery; however, up to 1 in 4 who undergo minor surgery and 1 in 5 who undergo major conservative surgery with ovarian preservation require additional endometriosis surgery. Up to 1 in 3 patients who had uterine sparing endometriosis surgery subsequently sought an infertility assessment. These findings may inform preoperative counseling in terms of recurrence of symptoms, fertility outcomes, and need for reoperation of women seeking surgical management for endometriosis. Future studies should consider the outcomes of patient satisfaction and quality of life based on the current practices for management of endometriosis.