Which of the ovarian veins is more susceptible and why?
The left ovarian vein. The ovarian (gonadal) vein anatomy is asymmetrical. The right ovarian vein drains directly into the IVC, whereas the left ovarian vein drains into the left renal vein, which has a long route from the IVC.
What is the most common cause of ovarian vein thrombosis?
It occurs most commonly in the post-partum state.
Residual tumour in the left side of the pelvis from the primary ovarian malignancy, with a large right para-aortic lymph node metastasis at the level of the renal vessels. The distal part of the long left renal vein does not contain contrast, at the junction with the left ovarian vein. The left ovarian vein can be followed in its entirity, with enhancing walls, but largely occupied with thrombus. In this case the presumed cause is obstructed flow from the lymph node mass.