OC02.06: Ultrasonographic “sliding sign” in the diagnosis of pouch of Douglas (POD) obliteration in women with clinical suspicion of endometriosis: relationship with the duration of surgery

to evaluate real-time dynamic transvaginal ultrasound (TVS) in the prediction of pouch of Douglas (POD) obliteration in women undergoing laparoscopy for suspected endometriosis and the relationship with the duration of surgery. 171 patients (mean age, 34 years) with clinical suspicion of deep pelvic endometriosis were prospectively enrolled and before laparoscopy underwent a detailed pre-operative TVS, in particular, to ascertain whether the POD was obliterated. POD obliteration was assessed using a real-time TVS technique called the “sliding sign”. These pre-operative TVS “sliding sign” findings were then compared to laparoscopic POD findings. Sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratios were calculated with 95% confidence intervals (CIs). We also compared the duration of surgery in the two groups with and without ultrasonographic suspicion of obliteration of POD. At laparoscopy, 85 patients had an obliterated POD. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio for using the “sliding sign” ultrasound technique to predict POD obliteration were 88% (95%CIs 82–92), 93% (95%CIs 87–97), 92% (95%CIs 86–96), 89% (95%CIs 83–92), 12.6 (95%CIs 5.82–27) and 0.13 (95%CIs 0.07–0.23), respectively . The pre-test probability of occlusion of POD was 50%, and this probability increased to 93% when POD seems occluded using TVS and fell to 11% when this ultrasonographic finding was absent. The duration of surgery was significantly longer in patients with ultrasonographic suspicion of occlusion of POD (Mean+SE, 167 min +8 min and 134 min +6 min, respectively, P = 0.006). Real-time dynamic TVS evaluation of the posterior compartment using the “sliding sign” seems a simple and accurate test to suspect the presence of POD occlusion and to predict the duration of laparoscopic surgery. This study was supported in part by the Regione Autonoma della Sardegna (project code CPR-24750).