Anatomy of the gonadal veins: a reappraisal.

Variations in anatomy were found quite frequently during bilateral gonadal vein dissection and resection for pelvic varices in the past 5 years (120 cases). In about one fourth of the cases, routine gonadal phlebography was not technically feasible or did not correlate exactly with the operative findings. Some cases of male varicocele showed recurrence after surgery. These facts, in addition to the scarce information provided by anatomy textbooks, induced us to study thoroughly the gonadal veins. One hundred cadaver dissections (200 veins) were done for length, diameter, number, and location of valves and collaterals, number of trunks in each side, and mode of termination in the renal vein and vena cava. Topographic division of the veins by thirds facilitated the information. Variations from the classic anatomic description were encountered frequently. As to the number of trunks, at the middle third, where the vein is usually divided, only 60% have one trunk on the left and only 75% have one on the right side. The rest are multiple; as many as four and six trunks in the lower third were found. The knowledge of these anatomic variations, not clearly described before, is of great importance to both surgeons and invasive radiologists and conducive to successful results.