Preoperative Ultrasound Scoring of Endometriosis by AAGL 2021 Endometriosis Classification Is Concordant with Laparoscopic Surgical Findings and Distinguishes Early from Advanced Stages

STUDY OBJECTIVE: To compare the accuracy of preoperative ultrasound (US) in predicting the laparoscopically defined 2021 American Association of Gynecologic Laparoscopists (AAGL) Endometriosis Staging. DESIGN: Retrospective multicenter study of patients treated at 3 specialized endometriosis centers. SETTING: Three specialized endometriosis surgical centers in São Paulo (Brazil), Barcelona (Spain), and Avellino (Italy) participated. PATIENTS: A total of 878 patients aged 15 to 45 years with no history of pelvic malignancy underwent laparoscopic (LPS) treatment for suspected endometriosis. INTERVENTIONS: Retrospective review of preoperative transvaginal and transabdominal US (index test) assessed for endometriosis at all sites used in the 2021 AAGL Endometriosis Classification and classified patients into AAGL-US stages 1 to 4. Results were compared with reference-standard LPS (AAGL-LPS) staging. MEASUREMENTS AND MAIN RESULTS: The AAGL-US and AAGL-LPS stage were concordant in 586 cases (66.7%) (weighted kappa [WK] 0.759; intraclass correlation = 0.906), with the highest agreement observed in patients with no endometriosis (n = 70, 75.3% concordance), AAGL-LPS stage 1 (104, 50.7%) and stage 4 disease (358, 88.2%). Endometriosis was most accurately diagnosed in the rectum/sigmoid colon (WK 0.862), bladder (WK 0.911), and ovaries (WK 0.835/0.795 for right/left, respectively) and least accurately diagnosed at superficial peritoneal (WK 0.442), tubal (WK 0.391/0.363 for right/left, respectively), and retrocervical/uterosacral ligament (WK 0.656) sites. CONCLUSION: Sonographic estimation of the 2021 AAGL Endometriosis Staging is greatest in AAGL-LPS stages 1 and 4 and among patients with no endometriosis. US best identifies endometriosis of the ovaries, bladder, and bowel but is more limited for the tubes and superficial peritoneum.