Analysis of risk factors for the removal of normal ovarian tissue during laparoscopic cystectomy for ovarian endometriosis

BACKGROUND The aim of this study was to identify risk factors for the removal of normal ovarian tissue during laparoscopic cystectomy for endometriosis. METHODS A total of 121 patients who had histologically confirmed ovarian endometriosis and 56 control patients who had other histologically confirmed benign cysts were included for the present analysis. The blocks of removed tissue were sectioned at 120 µm intervals and a total of five sections were analyzed for each ovarian cyst. Eight variables (age, pre-operative medical treatment, previous surgery for ovarian endometriosis, single or multiple cysts, size of the largest cyst, side of cyst, co-existence of deep endometriosis, revised American Society for Reproductive Medicine classification) were evaluated using a generalized linear modeling analysis to identify major factors associated with the removal of normal ovarian tissue. RESULTS Normal ovarian tissue adjacent to the cyst wall was detected in 71 patients (58.7%) with endometriosis, whereas normal ovarian tissue was removed from only three patients (5.4%) with other benign cysts. A significant factor that was independently associated with the removal of normal ovarian tissue with ovarian endometriosis was pre-operative medical treatment. CONCLUSIONS The present retrospective, controlled study suggests that pre-operative medical treatment might be a risk factor for the removal of normal ovarian tissue during laparoscopic cystectomy for ovarian endometriosis.