Clinical Implications of Sexual Dimorphism in Gonadal Vein Valves

The clinical significance of valves within gonadal veins is controversial. In males, the absence of valves in the left testicular vein (compared to the right) has been cited as a potential mechanism for varicocele formation in the pampiniform plexus in the scrotum. In females, ovarian vein valve absence or incompetence may lead to pelvic congestion syndrome, a disputed explanation for pelvic, abdominal, and/or flank pain of unknown etiology. One study suggests that females have incompetent valves in dilated veins more frequently than males due to past pregnancies. Furthermore, inconsistencies exist in the reported incidence of gonadal vein valves, though pelvic insufficiency is more thoroughly documented and diagnosed in males than in females. This study assesses the presence, number, and location of gonadal vein valves in male and females. The right and left gonadal veins were evaluated in 13 embalmed cadavers (7 males, 6 females; mean age = 86.3 +/− 6.2 years). Twenty‐four veins were available for dissection; two veins were lost to dissection and therefore omitted. The veins were dissected from the ovary (females) or deep inguinal ring (males) to the point of drainage into the inferior vena cava (right gonadal vein) or left renal vein (left gonadal vein). The veins were incised along the entire length of this course, and the number and location of valves was noted and photographed. Anatomical variation and pathological dilation in the vasculature was also documented. A total of 8 valves were found among the 24 dissections. Valves were present in four of the six females (67%) compared to one out of seven males (14%). The valve in the male was located in the left gonadal vein; the bilateral distribution in females was more randomly patterned. The majority of the valves (87.5%) in females were located distally, adjacent to the ovary, while a single valve was located adjacent to the left renal vein confluence. No dilation was noted in any of the specimens. The male population in this study had a lower incidence of gonadal vein valves than in previous studies. However, the number of valves in female gonadal veins was considerably greater than in males. This finding has not been reported previously, perhaps due to the emphasis on male pelvic congestion as a risk for infertility versus attributing the condition in females to a psychosomatic etiology. The primary limitation of this research is the small sample size. Future work will explore the clinical implications of these preliminary findings in a patient population. Clinical correlation with patients who are suspected or known to suffer from pelvic congestion syndrome may shed further light on the role of gonadal vein valves in vein sufficiency and inform more effective treatment for this poorly understood condition in the female patient population.