The use of transvaginal ultrasound and sonovaginography in the diagnostic work up of women with chronic pelvic pain who are scheduled for endometriosis surgery

Endometriosis is a major cause of chronic pelvic pain (CPP) and is thought to affect between 6-10% of women in the reproductive age range. Currently, the standard transvaginal sonography (TVS) examination of the pelvis does not asses for the presence of deep infiltrating endometriosis (DIE) or associated pelvic adhesions for women with CPP/suspected endometriosis. Pelvic DIE is a severe form of endometriosis, which affects structures such as the bowel, bladder, vagina, and uterosacral ligaments. Complex pelvic adhesions may also form as a result of endometriosis. Pouch of Douglas (POD) obliteration is caused by adhesions between the posterior uterine cervix/fundus and anterior rectum/rectosigmoid bowel, and is significantly associated with rectal DIE. The dissection of complicated pelvic adhesions and excision of pelvic DIE requires the skills of an advanced laparoscopic surgeon +/- colorectal surgeon. The ability to identify these high risk women pre-operatively allows for appropriate referral to an advanced laparoscopic surgeon, and in turn, adequate surgical planning and patient counselling. The prospective observational studies conducted for this thesis have contributed to the progression of a specialised TVS work up for women with CPP/suspected endometriosis by demonstrating: 1) the TVS “sliding sign” has a high accuracy in the prediction POD obliteration pre-operatively, 2) the inter-/intra-observer agreement for the TVS “sliding sign” and prediction of POD obliteration is substantial to almost perfect for expert gynaecological sonologists, 3) ultrasound based models do not appear improve the diagnostic accuracy of the TVS “sliding sign” alone to predict POD obliteration, 4) Gel sonovaginography has a high sensitivity for bowel DIE, as well as a high specificity and negative predictive value for posterior compartment DIE, and 5) ultrasound soft markers such as ovarian immobility and site-specific tenderness appear to have a significant relationship with the presence/ location of peritoneal endometriosis. Our research has also contributed to the development of an international consensus statement on the systematic approach to the TVS assessment of women with suspected endometriosis, as well as the nomenclature used to describe the sonographic features for pelvic DIE.