OC13.03: Can we predict pouch of Douglas obliteration using a new real‐time ultrasound technique: the ‘sliding sign’

The aim of this study was to evaluate pre-operative real-time dynamic transvaginal ultrasound (TVS) in the prediction of pouch of Douglas (POD) obliteration in women undergoing laparoscopy for suspected endometriosis. Multi-centre prospective observational study undertaken from January 2009 to November 2011. All women with symptoms suggestive of endometriosis scheduled for 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 gold standard laparoscopic POD findings. 100 consecutive women with pre-operative TVS and laparoscopic outcomes were included in the final analysis. Mean age was 32.8 years and mean age for diagnosis of endometriosis was 27.4 years. 84/100 (84%) were found to have some form of endometriosis at laparoscopy (73% peritoneal endometriosis, 35% ovarian endometrioma/s, 34% deep infiltrating endometriosis). At laparoscopy, 30/100 (30%) had an obliterated POD and 20/30 (66.7%) of these women also had evidence of bowel endometriosis. The accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio for using the real-time ‘sliding sign’ ultrasound technique to predict POD obliteration were 92.0%, 80.0%, 97.1%, 92.3%, 91.9%, 28.0 and 0.21, respectively. Pre-operative real-time dynamic TVS evaluation of the posterior compartment using the ‘sliding sign’ seems to establish whether the POD is obliterated with a high degree of certainty.