Evaluation of the association between self-reported pre-operative symptoms with surgically diagnosed endometriosis using the #ENZIAN classification in a multi-centre cohort

Study question: Is there an association between pre-operative symptoms and intraoperatively described localization and size of endometriosis lesions as assessed by the #ENZIAN classification system? Summary answer: Dyschezia is associated with any deep infiltrating endometriosis (DE) lesions; severe dyspareunia is associated with adenomyosis. What is known already: Previous attempts to correlate the common symptoms of endometriosis to the size and localization of lesions have been of moderate success. Study design, size, duration: This prospective, multicentre, non-interventional cross-sectional study was conducted between September 2022 and January 2024 at 18 endometriosis centres in Austria, Germany, and Switzerland, enrolling a total of 838 patients with endometriosis. Participants/materials, setting, methods: The study included 521 patients with complete information on pre-operative symptoms and intraoperatively diagnosed endometriosis classified by the #ENZIAN classification system. Associations between symptoms and localization of endometriosis lesions were analysed. Main results and the role of chance: Nearly all patients (n = 513) (98.5%) suffered from dysmenorrhea whereas 294 (56.4%), 208 (39.9%), and 102 (19.6%) patients reported dyspareunia, dyschezia, and dysuria, respectively. Dyspareunia rated as ≥8 on a visual analogue scale was reported 3.5-fold more often in patients with adenomyosis only (OR 3.56 [1.38-9.17]) than in those without, while dyschezia was almost twice as likely in those with any form of DE (OR 1.86 [1.3-2.65]). Limitations, reasons for caution: A larger study population is needed to clinically define relevant sub-groups based on localization of lesions. Wider implications of the findings: The findings of the present study identify adenomyosis as a strong driver of pain, especially dyspareunia, making awareness of its high prevalence of utmost importance. Few direct associations between symptoms and lesions were identified. Endometriosis-related symptoms, especially when chronic, are multi-factorial and cannot be readily correlated to specific lesion sites. Study funding/competing interest(s): This study received no external funding and all the authors declare they have no conflicts of interest pertaining to this study.