Intraoperative transvaginal ultrasound: a novel approach to refine surgical strategy in rectosigmoid endometriosis surgery

PURPOSE: To describe a standardized intraoperative transvaginal ultrasound (IOTVUS) technique for assessing rectosigmoid deep infiltrating endometriosis (DIE), and to explore its potential advantages in guiding real-time surgical decision-making. METHODS: This technical report outlines a stepwise protocol for performing IOTVUS during laparoscopic surgery. Following pelvic dissection and bowel mobilization, the pelvis is filled with saline to improve acoustic transmission. A 2D convex end-fire transvaginal probe is inserted to assess the rectosigmoid colon. Lesions are evaluated in multiple planes, measuring their dimensions, depth, circumferential involvement, and proximity to the anal verge. Findings are used intraoperatively to guide the choice of surgical approach-shaving, disc excision, or segmental resection. RESULTS: IOTVUS provides real-time, high-resolution imaging of rectosigmoid DIE, enabling accurate characterization of lesion morphology after anatomical restoration. The technique facilitates the selection of the most appropriate surgical intervention based on objective, intraoperative assessment. It also allows post-excision verification of lesion removal. CONCLUSION: IOTVUS is a promising, underutilized tool for intraoperative guidance in rectosigmoid DIE surgery. It supports precise lesion characterization and personalized surgical planning.