Endometriosis on the uterosacral ligament: a marker of ureteral involvement.

OBJECTIVE: To evaluate the association between ultrasound measurements of endometriosis nodules on the uterosacral ligament (USL) and the risk of ureteral involvement, as well as to assess whether associations with other ultrasound variables increase the sensitivity and specificity of the diagnosis of ureteral endometriosis.

DESIGN: Cross-sectional, observational study.

SETTING: University hospital.

PATIENT(S): Four hundred sixty-three women with deep infiltrating endometriosis (DIE).

INTERVENTION(S): Patients diagnosed with DIE underwent transvaginal ultrasound endometriosis mapping before laparoscopic surgery for full excision of endometriotic lesions.

MAIN OUTCOME MEASURE(S): Preoperative ultrasound evaluation, intra- and postoperative assessment, and anatomopathologic confirmation.

RESULT(S): Of the 463 patients who participated in the study, 111 (23.97%) presented with endometriosis nodules with USL involvement on ultrasound examination conducted by a single radiologist. Receiver operating characteristic curve analysis showed that the size of the USL nodule had a statistically significant association with ipsilateral ureteral involvement. After multivariate logistic regression, the variables reduction in ovarian mobility, ureteral changes on the right side, size of the USL nodule, and presence of endometrioma on the left side were significantly associated with a ureteral endometriosis nodule. However, the combined result for the variables cited was worse than the diagnostic analysis using only the size of the USL nodule.

CONCLUSION(S): Uterosacral ligament nodules with ultrasound measurements of 1.75 cm and 1.95 cm on the right and left sides, respectively, significantly increase the risk of ureteral involvement. Even with the association of other ultrasound variables, there was no improvement in sensitivity. Therefore, USL nodule size is a key measure for therapeutic planning and consent of the patient.