Venous intravasation during evaluation of tubal patency by ultrasound contrast imaging

A 32-year-old woman, without history of uterine intervention or pelvic surgery, underwent complete evaluation of uterine anatomy and tubal patency after failing to conceive for 30 months. Examination was performed by ultrasound, using saline, air/saline and foam as contrast media, on the 8th day of the menstrual cycle in an outpatient setting (Ludwin & Ludwin Gynecology, Krakow, Poland). Initial ultrasound evaluation, using a GE Voluson E8 Expert BT13 ultrasound system (GE Medical Systems, Zipf, Austria), showed normal/arcuate morphology of the uterus (Figure S1), and right and left ovaries with normal morphology, measurements and antral follicle count1. A 5-Fr balloon catheter (Softinjector, RI.MOS, Mirandola, Italy) was inserted into the cervical canal and the balloon was filled with 1 mL of saline. During assessment of the uterine cavity, an isoechogenic area was identified close to the left tubal ostium, possibly attributed to mucus or a clot (Figure 1a, b). Three-dimensional datasets of the uterus were acquired for offline evaluation, including uterine cavity volume estimation (Figure S2)2 and proximal tubal ostial assessment (Figure 2). During infusion of air/saline (10 mL of saline and 10 mL of air), the initial impression was that both Fallopian tubes were patent, as it was possible to identify bubbles flowing on both sides of the uterus, suggesting normal tubal anatomy. However, after careful examination of the images, normal flow through the lumen of the intramural portion of the Fallopian tube was observed only on the right side; the air bubbles reached the 'left tube' by several different paths, none of them resembling the normal morphology of the intramural portion of the tube (Videoclip S1). In fact, we believe that the bubbles were leaving the uterine cavity through the myometrial vessels and venous plexus, and reached the tubal and/or ovarian veins (Figure S3). Evaluation of tubal patency using foam (ExEM® Foam-kit, hydroxyethylcellulose, glycerol and purified water; GynaecologIQ, Delft, The Netherlands) as contrast medium3 and power Doppler identified flow only in the right tube (Figure 1c) without signs of venous intravasation. There was no complication or pain following the examination and after a 2-h observation period the patient left the clinic. Although we were not able to identify any previous report of venous intravasation during ultrasound assessment of tubal patency, this is a well-described complication of hysterosalpingography that occurs in approximately 7% of procedures using either oil-based or hydrosoluble contrast medium4, 5. Venous intravasation occurs more frequently when the examination is performed during the early- or late-follicular phase, and in women with previous uterine surgery, uterine anomalies, intrauterine adhesions and abnormal uterine bleeding, or if trauma is caused during catheter insertion4. The most severe possible consequence of venous intravasation is cerebral and pulmonary oil embolism; however, even when using hydrosoluble contrast medium, venous intravasation can increase complications such as fever, infection and pain4. Additionally, venous intravasation can lead to false-negative results, as it can be misinterpreted as indicating tubal patency. This phenomenon might be quite common considering that intravasation has not been reported previously during ultrasound assessment of tubal patency. Studies evaluating the frequency of venous intravasation using different ultrasound contrast media should be encouraged. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.