OP07.03: Clinical significance of left to right uterine venous shunting

Assessment of uterine venous circulation has been increasingly performed during routine transvaginal ultrasound (TVUS) to investigate gynecological symptoms. We have observed marked variation in organisation of uterine venous blood supply with evidence of continuous venous flow shunting from the left uterine venous plexus through the myometrial arcuate veins into the right uterine venous plexus. The aims were to characterise these variations, specifically, left to right uterine venous shunting, and assess clinical significance. This prospective observational cross-sectional study from February 2021 and September 2022 involved patients undergoing a consultation and routine TVUS of the pelvic organs including colour Doppler studies of uterine venous circulation. Premenopausal patients without gynecological pathology on ultrasound were included. Multivariate analysis assessed associations between shunting and demographic, clinical and ultrasound features. A total of 216 patients met the inclusion criteria. Their median age was 31 years [IQR 17-36], median BMI 23.8 kg/m2 [IQR 20.9 – 27.1] and majority were nulliparous 129/216 (59.7%). Uterine venous shunting was observed in 44/216 (20.4%) patients. A lower BMI was significantly associated with shunting [OR 0.81 (95%CI 0.81-0.97) (P = 0.02)]. No significance was noted between shunting and symptoms of menorrhagia, dysmenorrhea, irregular bleeding, dyspareunia or bowel and bladder symptoms. Presence of a dilated left uterine vein was significantly associated with shunting [OR 9.25 (95%CI 2.54-44.92) (P = 0.001)]. The combination of non-cyclical pelvic pain and dilated uterine veins was significantly associated with shunting [OR 3.82 (95%CI 1.29-12.00) (P = 0.01)]. In patients without gynecological pathology experiencing non-cyclical pelvic pain and had ultrasonographic evidence of dilated uterine veins, left to right uterine shunting could be a causative factor, warranting further investigation for pelvic congestion syndrome.