Parametrial Endometriosis: the Occult Condition that Makes the Hard Harder.

STUDY OBJECTIVE: Despite the enormous impact of lateral parametrial endometriosis (LPE), only a few studies have evaluated its diagnosis, prevalence, and clinical features. Our aim was to estimate the intraoperative prevalence of LPE in patients affected by deep infiltrating endometriosis (DIE) and to analyses clinical and surgical data associated with LPE.

DESIGN: Retrospective cohort study (Canadian Task Force classification II-2).

SETTING: Endometriosis tertiary level referral center, Sant'Orsola Academic Hospital, Bologna, Italy.

PATIENTS: We included 1360 consecutive women submitted to surgery for DIE between 2007 and 2017. Patients were divided into 2 groups according to the presence (study group, n = 231) or absence (control group, n = 1129) of LPE.

INTERVENTION: We retrospectively compared data records on the demographic features, preoperative data, and surgical outcomes of the 2 groups.

MEASUREMENTS AND MAIN RESULTS: The intraoperative prevalence of LPE was 17%. Preoperatively, LPE patients complained of having a more severe intensity of dysmenorrhea (p <.001), more frequent voiding symptoms (p <.001), and more constipation (p = .02). At surgery, significant correlations were found with rectovaginal septum, vaginal, rectal, and ureteral involvement (p <.001). LPE patients intraoperatively presented a concomitant posterior nodule with a larger transverse diameter (p <.001). The operation time and hospital stay were longer for patients with LPE. Postoperatively, the LPE group needed self-catheterization more often than the control group at discharge (p <.001) and at the 1-month follow-up evaluation (p = .001).

CONCLUSIONS: LPE is a condition that reflects a more severe manifestation of endometriosis, requiring more aggressive surgery.