Deep endometriosis: the IDEA consensus and the role of transvaginal ultrasound

A systematic pelvic assessment protocol has made transvaginal ultrasound the first-line investigation for deep endometriosis, when performed by a trained examiner.

Until 2016, ultrasound assessment of endometriosis suffered from a structural problem: each research group used different terms and criteria, making it hard to compare studies. The consensus from the IDEA group (International Deep Endometriosis Analysis) fixed this by proposing a systematic four-step approach.

The protocol's four steps

The protocol sequentially assesses: the uterus and adnexa on the routine exam; indirect markers such as pelvic organ mobility; the presence of endometriomas; and a targeted search for deep endometriosis nodules in the anterior and posterior compartments — including the uterosacral ligaments, rectovaginal septum, bladder, and bowel.

Accuracy depends on who is examining

Recent studies describe an overall accuracy above 80% for detecting deep endometriosis with this systematic approach — but the accuracy reported in the literature is consistently higher when the exam is performed by an examiner specifically trained in the protocol, reinforcing that the learning curve is a central part of the method.