Prediction of Vesicouterine Adhesions by the Real-time Dynamic Transvaginal Sonographic Sliding Sign Technique: a Validation Study

The investigators will conduct a prospective observational double-blind cohort study of patients who will have laparoscopic abdominopelvic surgery between January 2020 and December 2022 in the Amsterdam UMC. All women will be examined by TVE ultrasounds prior to surgery. The investigators will evaluate the predictive value of the real-time dynamic TVS sliding sign for vesicouterine pouch adhesions in women and test the inter- and intraobserver agreement of this technique.

All real-time dynamic transvaginal ultrasounds will be performed as followed: By mild pressure with the vaginal probe in the anterior vagina and palpation on the fundus with the free hand, the uterus will be pushed away from the bladder. The sliding-sign will be considered to be positive when the anterior wall glided freely in relation tot the bladder, one against the other. The sliding-sign was negative when the bladder is fixated tot the uterus for more than 1 cm from the vesico-vaginal fold. Or when the distance between the vesico-vaginal fold and the vesico-uterine fold is > 1 cm.

Two experienced gynaecologists and one resident in gynecology and obstetrics will evaluate the ultrasounds on the presence of the sliding sign independent from each other and without any knowledge of the individual patient and laparoscopic footage. All ultrasounds will be coded, so the assessors are blinded for the patients demographics and surgical history in order to interpret the sliding sign objectively.

The recorded laparoscopic videoclips will be evaluated by one of the researchers without any knowledge of the individual patient, surgical history and ultrasounds. Therefore the laparoscopic footage will be coded. To prevent bias the assessor will be blinded to the results of the ultrasound sliding sign assessments. Adhesions between uterus and bladder, abdominal fascia and omentum are scored according the classification of Tulandi. An adhesion score of 0 will be classified as no adhesions and an adhesion score of >16 as a 'frozen bladder'.

The obtained data will be analyzed to determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the sliding sign to predict the presence of absence of adhesions between the bladder and uterus. Fisher's exact test will be used to calculate the p-value for prediction of adhesions using the sliding sign technique. A P < 0.05 will be considered statistically significant. Interobserver variability will be assesed between two experienced gynecologists and between one experienced gynecologist and the resident. To assess the intraobserver variability one of the experienced gynecologists will reevaluated the same ultrasounds 2 months after the first ultrasound evaluation.