High sliding sign: a new soft marker of uterine fundus compromise in deep infiltrating endometriosis

Deep infiltrating endometriosis (DIE) is a disease that affects approximately 8–15% of fertile women. Because of this high prevalence, ultrasound examination has become a mainstay in clinical practice, which is supported by substantial evidence1. Among the sonographic findings of DIE, one appears to be a particularly useful tool, the so-called ‘sliding sign’ that was reported by Reid et al. in 20132. This sign allows identification of the presence of adhesions around the uterus, determines the immobility of the uterus in relation to its neighboring structures and indicates indirectly the presence of an obliterated pouch of Douglas (POD). This has been demonstrated previously in different studies3, 4. When diagnosing DIE, the sliding sign is not 100% accurate, as expected for any ultrasound finding. In our study, among the 96 patients with surgically-proven DIE, six had a negative sliding sign (i.e. the cervix did not slide against neighboring structures) but demonstrated a non-obliterated POD, as defined by adhesions below the level of insertion of the uterosacral ligaments but with adhesions at the level of the uterine fundus. This could have explained the absence of cervical mobility (Videoclip S1). Moreover, 46 patients had a positive sliding sign at the uterine fundal level with no adhesions observed but a negative sliding sign of the cervix, which we would define as ‘true negative’ with uterosacral ligament infiltration (Videoclip S2). For this reason, we propose subdividing the sliding sign into ‘high sliding sign’, suggestive of uterine fundus compromise, and ‘low sliding sign’, which would suggest obliteration of the POD, with or without vaginal involvement. Using this proposed subdivision, a more difficult surgery could be anticipated for women with a non-obliterated POD but a negative sliding sign, which indicates uterine fundal adhesions and a sealed pelvis. M. León*† and J. L. Alcazar‡ †Department of Obstetrics and Gynecology, Ultrasound Unit, Clínica Indisa, Santiago, Chile; ‡Department of Obstetrics and Gynecology, Clínica Universidad de Navarra, University of Navarra, Pamplona, Spain *Correspondence. (e-mail: [email protected]) Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.