Transvaginal sonography accurately determines extent of infiltration of rectosigmoid deep endometriosis

Objectives To investigate the agreement of the three diameters of the rectosigmoid deep endometriosis (DE) between pre-surgical evaluation with transvaginal sonography (TVS) and post-surgical specimen measurements (PSM). Methods A prospective observational multi-center study including symptomatic women undergoing surgical treatment for DE of the rectosigmoid by either discoid or segmental resection. TVS was performed pre-surgically to evaluate lesion size in accordance with the International Deep Endometriosis Analysis (IDEA) group consensus statement and was compared to PSM. The agreement between the two methods regarding lesion dimensions were assessed by Bland-Altman plots, limits of agreement, and intraclass correlation coefficient (ICC) for additional analysis. Systematic and proportional bias was assessed with paired t-test. Results From April 2017 to December 2019, a total of 207 consecutive women were eligible for inclusion. Forty-one were excluded, leaving 166 women for final analysis. A total of 123 segmental resections and 46 discoid excisions were performed. The mean difference between TVS and PSM measurements regarding lesion length was 0.90 mm (95% CI: 0.85-0.95 mm), lesion thickness 1.03 mm (95% CI: 0.98-1.09 mm) and lesion depth 0.84 mm (95% CI: 0.79-0.89 mm). The Bland-Altman plot showed good agreement between the two measuring methods for lesion length. Furthermore, there was good reliability and correlation between TVS and PSM for lesion length demonstrated by the ICC 0.82 (95% CI: 0.75-0.87) and Pearson's correlation 0.72 (95% CI: 0.62-0.80), moderate reliability for lesion thickness with an ICC 0.76 (95% CI: 0.67-0.82) and Pearson's correlation 0.61 (95% CI: 0.51-0.70) and moderate-to-poor reliability for transverse diameters with an ICC 0.58 (95% CI: 0.39-0.71) and Pearson correlation 0.46 (95% CI: 0.33-0.58). Conclusion Pre-operative TVS accurately determines rectosigmoid DE lesion length. TVS can thereby contribute to optimal planning of surgical treatment options in women with rectosigmoid DE. This article is protected by copyright. All rights reserved.