Transvaginal sonography determines accurately extent of infiltration of rectosigmoid deep endometriosis

ABSTRACT Objective To investigate the agreement of measurements of the three diameters of rectosigmoid deep endometriosis (DE) lesions between presurgical evaluation using transvaginal sonography (TVS) and postsurgical specimen measurement (PSM). Methods This was a prospective observational multicenter study including symptomatic women undergoing surgical treatment for DE involving the rectosigmoid, by either discoid or segmental resection, from April 2017 to December 2019. TVS was performed presurgically to evaluate lesion size (craniocaudal–midsagittal length, anteroposterior thickness and transverse diameter), in accordance with the International Deep Endometriosis Analysis (IDEA) group consensus statement, and was compared with PSM. The agreement of lesion dimensions between the two methods was assessed by Bland–Altman plots and limits of agreement and additionally by the intraclass correlation coefficient (ICC) and Pearson's correlation coefficient. Systematic and proportional bias was assessed using the paired t‐test. Results A total of 207 consecutive women were eligible for inclusion. Forty‐one women were excluded, leaving 166 women for final analysis. A total of 123 segmental resections and 46 discoid resections were performed (both procedures were performed in three women). The mean difference between TVS and PSM was 0.90 (95% CI, 0.85–0.95) mm for lesion length measurements, 1.03 (95% CI, 0.98–1.09) mm for lesion thickness measurements and 0.84 (95% CI, 0.79–0.89) mm for transverse diameter measurements. Bland–Altman analysis demonstrated good agreement between the two methods for measurements of lesion length. Furthermore, there was good reliability and correlation between TVS and PSM for lesion length measurements, as demonstrated by an ICC of 0.82 (95% CI, 0.75–0.87) and Pearson's correlation coefficient of 0.72 (95% CI, 0.62–0.80), moderate‐to‐good reliability and correlation for lesion thickness measurements, with an ICC of 0.76 (95% CI, 0.67–0.82) and Pearson's correlation coefficient of 0.61 (95% CI, 0.51–0.70), and poor‐to‐moderate reliability and correlation for transverse diameter measurements, with an ICC of 0.58 (95% CI, 0.39–0.71) and Pearson's correlation coefficient of 0.46 (95% CI, 0.33–0.58). Conclusion Preoperative TVS determines accurately rectosigmoid DE lesion length. TVS can thereby contribute to optimal planning of surgical treatment options in women with rectosigmoid DE. © 2021 The Authors. Ultrasound in Obstetrics & Gyne