Gonadal veins (testicular / ovarian)
Vena testicularis / Vena ovarica
Also known as: testicular vein, ovarian vein, pampiniform plexus
The gonadal veins drain the testes or ovaries. The right gonadal vein drains into the IVC, while the left drains into the left renal vein. This asymmetry explains why varicoceles are much more common on the left.
Overview
Pampiniform plexus. In men, the testis and epididymis drain into a network of 8–12 veins in the spermatic cord, the pampiniform plexus. The plexus surrounds the testicular artery and cools the arterial blood before it reaches the testis. At the deep inguinal ring the plexus merges into one or two testicular veins.
Course. The gonadal veins ascend on psoas behind the peritoneum, alongside the gonadal arteries. The right gonadal vein enters the IVC at an acute angle. The left gonadal vein joins the left renal vein at a right angle. Its longer column of blood, the higher pressure in the left renal vein and the possible compression of that vein between the aorta and the SMA all make the left side more prone to venous congestion. In women, the ovarian veins drain the ovary through a plexus in the broad ligament.
Function
- Drain the testes and epididymis or the ovaries.
- Help regulate testicular temperature by countercurrent heat exchange (pampiniform plexus).
Clinical significance
Varicocele
A varicocele is a dilated pampiniform plexus that feels like a "bag of worms" above the testis. About 90% are on the left. It is associated with reduced fertility. A varicocele that appears suddenly on the right, or one on the left that does not empty when the patient lies down, should prompt imaging for a renal or retroperitoneal tumour.
Pelvic congestion and ovarian vein thrombosis
Reflux down incompetent ovarian veins causes chronic pelvic pain (pelvic congestion syndrome). Ovarian vein thrombosis, usually on the right, can occur after childbirth.
Test yourself
The left testicular vein usually drains into the:
- Inferior vena cava
- Left renal vein
- Left common iliac vein
- Left internal iliac vein
Answer: Left renal vein
The left gonadal vein joins the left renal vein at a right angle, while the right gonadal vein joins the IVC directly. This asymmetry is one reason why about 90% of varicoceles are on the left.
Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.