OC13.01: The value of transvaginal ultrasound in assessing the severity of pelvic endometriosis

To assess if transvaginal ultrasound examination can accurately predict the severity of pelvic endometriosis. This would facilitate the triaging of patients with severe disease to specialist tertiary referral centres where their surgical care can be optimised. Women were recruited consecutively to join this prospective observational study from July 2006 to December 2008. Women with pelvic pain of greater than six months duration, booked for laparoscopy were examined pre-operatively using transvaginal ultrasound (TVS). The severity of endometriosis as assessed by TVS was compared with laparoscopy findings recorded using the revised American Fertility Association system. 201 women had pre-operative TVS and laparoscopies. Of these 62/201 (30.8%, 95% CI 23.7–36.3) had no endometriosis found at laparoscopy, 33/201 (16.4%, 95% CI 10.9–21.1) minimal disease, 31/201 (15.4%, 95% CI 10.1–19.9) mild disease, 27/201 (13.4%, 95% CI 8.35–17.65) moderate disease and 48/201 (23.9%, 95% CI 17.9–28.8) had severe disease. The sensitivity and specificity of TVS diagnosis of severe pelvic endometriosis were 0.85 (95% CI 0.716–0.934) and 0.98 (95% CI 0.939–0.994) respectively and the positive and negative likelihood ratios were 43.5 (95% CI 14.1-134) and 0.15 (95% CI 0.075-0.295) respectively. Transvaginal ultrasound performed by experienced operators has a high sensitivity and specificity at detecting severe pelvic endometriosis. This result indicates that TVS is a good method for triaging women with pelvic endometriosis for optimal surgical care.