1852 The Prevalence of Pouch of Douglas Obliteration Depicted on Basic Transvaginal Ultrasound by a Negative Sliding Sign in a General Population

Abstract

Study Objective Pouch of Douglas (POD) obliteration can be predicted with a high degree of certainty in patients with symptoms of endometriosis using transvaginal ultrasound (TVS). Studies on POD obliteration and the sliding sign, as part of an expert-guided deep endometriosis (DE) TVS, have always focused on populations in tertiary care centres with high disease prevalence. Our aim is to determine the prevalence of a negative sliding sign on basic TVS in a general population. Design Prospective observational study. Setting Gynecology-focused ultrasound practice. Patients or Participants Consecutive patients visiting the practice for a gynecological TVS. Interventions The sliding sign was performed to determine the POD state. Measurements and Main Results Descriptive statistics were applied to the entire population and subgroups of patients high- and low-risk for endometriosis. High-risk for endometriosis was defined as having a TVS referral for endometriosis-related pelvic pain or specifically “endometriosis” and/or clinical symptoms suggestive of endometriosis. Low-risk was defined by the absence of these features. 1043 patients underwent TVS. Patients who underwent a transabdominal ultrasound (5.6%) and history of hysterectomy (1.3%) were excluded; 971 were eligible. The sliding sign was performed and interpreted in 922 patients. Prevalence of a negative sliding sign in the general, high-risk, and low-risk populations was 47/922 (5.1%), 25/243 (10.3%), 22/639 (3.4%) (p Conclusion We have shown that the prevalence of POD obliteration on ultrasound evaluation in the general population is roughly 1 in 20, which may serve as the foundation for future studies on the sliding sign in lower-risk populations as this dynamic ultrasound technique becomes increasingly understood and adopted.