Dual ultrasound combination improves the accuracy of preoperative assessment in rectal endometriosis: a prospective cohort study

Background: Rectal endometriosis is a complex condition requiring multidisciplinary treatment. Accurate preoperative assessment is critical for selecting the appropriate surgical technique, with transvaginal ultrasound (TVS) and endorectal ultrasound (ERUS) being key diagnostic tools. While TVS is effective in detecting ovarian endometriosis and pelvic deep infiltrating endometriosis (DIE), it has limitations in assessing bowel involvement. ERUS, however, provides detailed imaging of the rectal wall and depth of invasion. Materials and Methods: A single-center prospective cohort study included 23 patients suspected of rectal endometriosis between August 2023 and September 2024. Perioperative findings and questionnaires, including Endometriosis Health Profile-30 (EHP-30) and Gastrointestinal Quality of Life Index (GIQLI) were assessed. Results: Preoperative ERUS revealed that 82.6% of patients had a single rectal nodule, with a mean size of 2.1 ± 0.7 cm in length and 1.1 ± 0.6 cm in width. Luminal stenosis was found in two patients, and 100.0% of nodules extended into the muscular layer. TVS detected ovarian endometriosis and adenomyosis in 47.8% of patients and identified single rectal nodules in 60.9%, with a mean nodule length of 2.7 cm. Surgical approaches included rectal shaving (12 patients), disc excision (8 patients), and segmental resection (3 patients). Luminal stenosis was absent in the shaving and disc excision groups but present in 66.7% of segmental resection cases. The segmental resection group had significantly larger nodules (3.4 ± 0.5 cm length, 2.1 ± 0.8 cm width, 56.8 ± 0.4 cm 2 area). Postoperative complications were generally mild, with only one patient experiencing Grade II rectal bleeding. Significant improvements were observed in pain (p = 0.004), control and powerlessness (p = 0.004), emotional well-being (p = 0.035), work-related issues (p = 0.030), and sexual relationship quality (p = 0.044). Conclusion: Our study highlights that combining preoperative ERUS with TVS improves the accuracy of assessments, enabling a more tailored surgical approach that enhances surgical outcomes and optimizes the management of rectal endometriosis.