Transvaginal Ultrasound Can Accurately Predict the American Society of Reproductive Medicine Stage of Endometriosis Assigned at Laparoscopy.

Study Objective: To evaluate the diagnostic accuracy of transvaginal ultrasound in predicting a laparoscopic, surgically assigned, revised American Society of Reproductive Medicine (ASRM) endometriosis stage.

Design: A multicenter, retrospective, diagnostic accuracy study.

Setting: The patients visited 1 of 2 academic gynecologic ultrasound units and underwent laparoscopy led by 1 of 6 surgeons in metropolitan Sydney, Australia, between 2016 and 2018.

Patients: Patients with suspected endometriosis (n = 204).

Interventions: Ultrasound followed by laparoscopy.

Measurements And Main Results: Surgical cases were identified. The preoperative ultrasound report and surgical operative notes were each used to retrospectively assign an ASRM score and stage. The breakdown of surgical findings was as follows: ASRM 0 (i.e., no endometriosis), 24/204 (11.8%); ASRM 1, 110/204 (53.9%); ASRM 2, 22/204 (10.8%); ASRM 3, 16/204 (7.8%); ASRM 4, 32 204 (15.7%). The overall accuracy of ultrasound in predicting the surgical ASRM stage was as follows: ASRM 1, 53.4%; ASRM 2, 93.8%; ASRM 3, 89.7%; ASRM 4, 93.1%; grouped ASRM 0, 1, and 2, 94.6%; and grouped ASRM 3 and 4 of 94.6%. Ultrasound had better test performance in higher disease stages. When the ASRM stages were dichotomized, ultrasound had sensitivity and specificity of 94.9% and 93.8%, respectively, for ASRM 0, 1, and 2 and of 93.8% and 94.9%, respectively, for ASRM 3 and 4.

Conclusion: Ultrasound has high accuracy in predicting the mild, moderate, and severe ASRM stages of endometriosis and can accurately differentiate between stages when ASRM stages are dichotomized (nil/minimal/mild vs moderate/severe). This can have major positive implications on patient triaging at centers of excellence in minimally invasive gynecology for advanced-stage endometriosis.