Uterosacral ligament thickness: a novel ultrasound measurement for diagnosing endometriosis

All participants will complete a transvaginal ultrasound within 8 weeks prior to the planned laparoscopy (laparoscopy planned independent of the study). The ultrasound will take approximately 15minutes. -- All findings of deep endometriosis will be reported to the managing surgical teams, along with any other sinister pathological concerns. The additional assessment on pelvic ultrasound will include a measurement (in mm) of both USLs. This will be completed in an axial plane at the level of the internal cervical os, 10 mm from the medial insertion of the ligament. The measurement will include the lipomatous layer of the USL in this plane and will exclude the vascular and neural components of the ligament. In addition to this objective measurement, the mobility of the USLs, tenderness of the USLs and tenderness of the pelvic floor muscles will be dichotomised and recorded as yes/no. The USL measurements will not be reported to the managing clinicians. The assessment of the USL is not included in the current ASUM reporting guidelines for pelvic imaging. On the same day as the ultrasound, a 15minute questionnaire will be completed by the participant. All participants will undergo their scheduled laparoscopic pelvic surgery, as was planned irrespective of study involvement. The surgeon will capture standardised clinical pictures, plus additional pictures of visible disease. The surgeon will then take the standardised biopsies of each USL. These biopsies are to be taken at a standardized point (10mm from the medial insertion) and be of a size at least 10mm x 3mmThe surgery will then be completed with excision of other visible disease. The surgeon will complete a 5minute form describing the surgical findings. Histological specimens will be processed in the standard way by two anatomical pathologists.