OC19.04: Diagnostic value of transvaginal ultrasonography for the prediction of parametrial endometriosis

The role of ultrasound in the detection of the parametrial localisation of deep endometriosis although associated with ureteral stenosis and linked with a complex surgery with a high risk of intra and post-operative complications, is poor investigated. The aim was to evaluate the diagnostic accuracy of transvaginal ultrasonography in the identification of parametrial deep endometriosis. Consecutive women scheduled for surgery in a single centre for clinically suspected endometriosis were included in this prospective study. All women underwent transvaginal ultrasonography before surgery. The presence of parametrial endometriosis was considered when an infiltrating irregular hypoechogenic tissue extending laterally to the cervix was visualised. Sensitivity, specificity and likelihood ratios (LR+/-) were calculated with 95% confidence intervals (CIs). We included 476 women; surgery associated with histopathological evaluation revealed deep endometriosis in parametrial locations in 114 patients. With respect to the left parametrium, transvaginal ultrasonography had a sensitivity of 88% (95% CI, 79-94%), specificity of 98% (95% CI, 96-99%), an LR+ of 48.2 and an LR- of 0.12. Regarding to the right parametrium, transvaginal ultrasonography had a sensitivity of 91% (95% CI, 80-97%), specificity of 98% (95% CI, 96-93%), an LR+ of 63.8 and an LR- of 0.09. This technique shows, in a large population, a high specificity and sensitivity in the detection of parametrial endometriosis. This study was partly supported by Fondazione di Sardegna grant F74I19001010007.