Prominent venous intravasation in hysterosalpingo-contrast sonography (HyCoSy): A case report

Hysterosalpingo-contrast sonography (HyCoSy) is a commonly used technique for assessing fallopian tube patency. A well-recognized complication of this procedure is venous intravasation (VI), which refers to the unintended entry of contrast medium into the uterine and parametrial venous systems. This highly variable complication often leads to misdiagnosis, which in turn compromises the subsequent management and treatment of affected patients.

A 32-year-old female who underwent a 4-dimensional HyCoSy for secondary infertility initially appeared to have a rare congenital defect, with images revealing three distinct tube-like structures resembling fallopian tubes, one on the right side of the uterus and the other two on the left side, which is suspicious for fallopian tube duplication malformation.

Real-time 2-dimensional imaging and dynamic cine-loop recordings revealed that the contrast agent originated from myometrial vessels rather than the tubal ostia. This confirmed a diagnosis of extensive VI mimicking fallopian tube duplication malformation, coupled with bilateral tubal obstruction.

The diagnosis was substantiated by the absence of peritoneal contrast spillage and the observation of delayed ovarian stromal enhancement, a sign of systemic recirculation. The findings were further verified via hysteroscopy and an intra-operative chromopertubation test. Following this, the patient was referred for in vitro fertilization-embryo transfer.

After receiving appropriate fertility treatment based on the corrected diagnosis, the patient successfully achieved pregnancy via in vitro fertilization-embryo transfer.

Significant VI can manifest as organized "pseudo-tubular" structures that convincingly mimic congenital malformations. To ensure diagnostic precision, clinicians must track the anatomical origin of contrast egress and look for indirect signs of intravasation, such as delayed ovarian enhancement, to avoid unnecessary invasive procedures and guide correct clinical decision-making.