Objective To establish reference ranges for uterine vein (UtV) diameters in non-pregnant women with normal pelvic organs. Methods This was a prospective study of all women attending the general gynecological clinic of a university teaching hospital in the UK, between August 2015 and December 2016. All women aged ≥ 18 years underwent a transvaginal ultrasound examination in accordance with the study protocol. In women with normal pelvic organs, the largest trunk of the uterine venous plexus was identified in the transverse plane on each side. The maximum anteroposterior vessel diameter was measured by placing the calipers on the inner walls of the vein, and the mean of three measurements was used as the representative value. Inter-and intraobserver variability was assessed in a subgroup of 30 women. Maximum UtV diameter was compared between right and left UtVs and between pre-and postmenopausal women. Factors associated with UtV diameter were assessed and reference ranges were constructed. Results Of 1500 women examined, 486 (32%) had normal pelvic organs on ultrasound scan and were included in the final analysis. In all women, the uterine venous trunk was clearly visualized and there was no significant difference between the maximum median left and right UtV diameters (P = 0.37). UtV diameters were generally lower in postmenopausal, compared with premenopausal, women, with the difference being statistically significant for the right UtV and the average of left and right UtVs. There was a gradual increase in UtV diameter with advancing age, with a peak observed in women aged 41-50 years and decreasing values in older age groups. Univariable analysis showed that parity, menopausal status and age were associated significantly with UtV diameters (P < 0.01). On multivariable analysis, only higher parity was significantly associated with increasing venous size in both pre-and postmenopausal

Background: The uterine venous plexus (UVP) is an unusual site for venous thrombosis (VT). Our aim was to determine the prevalence of UVP thrombosis (UVPT) and identify associated risk factors. Methods: We conducted a cross-sectional study on consecutive nonpregnant women attending our general gynecology clinic with a wide variety of presenting symptoms over a 16-month period. All women underwent a transvaginal ultrasound scan which involved detailed examination of the uterine venous plexus. Women diagnosed with incidental UVPT had thrombophilia screening, lower limb venous duplex imaging, and specialist hematological review. Logistic regression was used to examine associations between various risk factors and UVPT. Results: We screened 1383 women, 39 of whom had an incidental UVPT, giving a prevalence of 3.0% (95% confidence interval [CI], 2.1%-4.1%). Multivariate analysis showed positive associations between multiparity (odds ratio [OR] 5.75 [95% CI 2.10, 15.7]), recent surgery (OR 3.10 [95% CI 1.19, 8.07]), presence of leg varicose veins (OR 3.15 [95% CI 1.32, 7.49]), and a family history of venous thromboembolism (OR 8.74 [1.65, 46.4]) and negative associations between postmenopausal status (OR 0.36 [95% CI 0.13, 0.95]) and the development of UVPT. Thrombophilia was detected in 12.8% women diagnosed with UVPT. Conclusions: The prevalence of incidental UVPT in a general gynecology population was 3.0%. Several demographic and clinical factors were found to be associated with UVPT. This could help to identify women at risk of this condition, and facilitate its early detection and development of evidence-based management strategies.

Background Transvaginal ultrasound (TVS) is a sensitive tool for detecting various conditions that contribute to pelvic pain. TVS can be also used to assess blood flow and measure the size of pelvic veins. Pelvic venous congestion (PVC) is characterised by enlargement of the pelvic veins and has been recognised as a cause of chronic pelvic pain. The reference ranges for uterine venous diameter in women with normal pelvic organs have been established, but there is no information regarding the potential effect of pelvic pathology on the uterine venous diameters. The aim of this study was to examine the size of uterine venous plexus in women with evidence of pelvic abnormalities on TVS and to determine whether the reference ranges need to be adjusted in the presence of pelvic pathology. A prospective, observational study was conducted in our gynaecological outpatient clinic. Morphological characteristics of all pelvic abnormalities detected on TVS and their sizes were recorded. The uterine veins were identified and their diameters were measured in all cases. The primary outcome measure was the uterine venous diameter. Regression analyses were performed to determine factors affecting the uterine venous size in women with pelvic pathology. Results A total of 1500 women were included into the study, 1014 (67%) of whom were diagnosed with pelvic abnormalities. Women with pelvic pathology had significantly larger uterine venous diameters than women with normal pelvic organs (p < 0.01). Multivariable analysis showed that pre-menopausal status, high parity, presence of fibroids (p < 0.001) and Black ethnicity were all associated with significantly larger uterine vein diameters. Based on these findings modified reference ranges for uterine venous diameters have been designed which could be used for the diagnosis of PVC in women with uterine fibroids. Conclusions Our findings show that of all pelvic pathology detected on TVS, only fibroids are significantly associated with uterine venous enlargement. Factors known to be associated with enlarged veins in women with normal pelvic organs, namely parity and menopausal status, also apply in patients with pelvic pathology. Future studies of uterine venous circulation should take into account the presence and size of uterine fibroids when assessing women for the signs of PVC.

The management of incidental or unusual site venous thrombosis (VT) is challenging and is often extrapolated from studies on symptomatic deep venous thrombosis (DVT). There is a tendency to treat with anticoagulation, due to the theoretical risk of propagation and embolism; however, this is not without risk. Furthermore, there is little guidance on how to monitor incidental VT. The aim of this study was to describe the natural history of incidental uterine venous plexus thrombosis (UVPT) and provide a structured approach to its overall management. A prospective study was conducted in a university teaching hospital over a 16-month period. Women diagnosed with UVPT on transvaginal ultrasound (TVS) were followed up over a six-month period and managed based on an individualised risk assessments, in conjunction with haematologists. Fifty women were diagnosed with UVPT during the study period, of which 38 were managed expectantly. The resolution was documented in 70% of women. There were no cases of symptomatic DVT or pulmonary embolisms in either the expectant or treatment groups. Our study has shown that in a high proportion of women, incidental UVPT could be managed successfully without the need for anticoagulation. The overall management of UVPT should be based on individualised clinical risk assessments.

Oral communication abstracts Consecutive postmenopausal polyps diagnosed on transvaginal ultrasound scan by a single operator were eligible. Women on tamoxifen were excluded. Polyps were assessed for the presence or absence of intralesional cystic spaces. Patient characteristics and polyp morphological features on ultrasound were evaluated for the association with cystic spaces by multivariate analysis. All polyps were confirmed histologically following hysteroscopic polypectomy or hysterectomy. Results: A total of 240 postmenopausal polyps were included. The prevalence of intralesional cystic spaces was 83/240 (34.6%); median diameter of the largest cystic spaces was 3.0mm (range 1.0-7.7). On multivariate analysis, older age (OR 1.07, 95% C.I. 1.03-1.11), larger polyp size (OR 1.16, 1.08-1.25), absence of postmenopausal bleeding (OR 2.46, 1.17-5.16) and women not exposed to HRT (OR 6.02, 1.99-18.21) were associated with the presence of cystic spaces. Patient's BMI, parity, history of hypertension, diabetes mellitus, presence of multiple polyps or detectable vascularity on Doppler were not associated with cystic spaces. Benign polyps were more likely to have intralesional cystic spaces compared to premalignant or malignant polyps, 82/222 (36.9%) vs 1/18 (5.6%), p = 0.007. Conclusions: Our findings were in keeping with intralesional cystic spaces as a feature of benign postmenopausal polyps. Morphological features of polyps on ultrasound may have the potential to improve risk prediction of premalignancy or malignancy. OC12.04 *Applicability of morphological uterus sonographic assessment features associated with adenomyosis among experts and refinements of definitions