Clinical implications of left ovarian vein incomplete duplicity with embryonic intersubcardinal anastomosis-derived branches.

During the dissection of a female human cadaver a case of a duplex ovarian vein was observed. It was unique in its upper course where it anastomosed with an inferior polar renal vein, which in turn was linked to an upper polar renal vein by means of a joining branch. It is hypothesised that this represent a persistent link between the left subcardinal vein and the left sacrocardinal vein, together with some branches of a venous net, which represent the embryological intersubcardinal anastomosis. The gonadal vein arises from the distal (or postrenal) left subcardinal vein portion; the left renal vein develops from the intersubcardinal anastomosis. The venous net derived from the intersubcardinal anastomosis may represent a bypass system in cases of left renal vein occlusion. Left gonadal vein duplicity may also play an important role in the anatomical basis of idiopathic left ovarian vein syndrome or left varicocele, and can lead to mistakes being made during venous sclerotherapy.