Pelvic Vein Glossary

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Adenomyosis: A condition where the lining of the womb grows into its muscle wall, causing heavy, painful periods. It can cause pain similar to pelvic congestion and can exist alongside it.

Chronic pelvic pain: Pain below the belly button that has lasted at least six months. It has many possible causes, and pelvic vein problems are one of them.
Coil (embolisation coil): A tiny spring of metal, usually platinum or stainless steel, placed inside a vein to block it. It stays in place permanently and is safe for most later scans, including MRI.
Compression: Squeezing of a vein from outside, usually by an artery, which can slow drainage and cause blood to back up. Nutcracker and May-Thurner syndromes are examples.
CT venography: A CT scan timed to show the veins after an injection of contrast dye. It maps the veins of the abdomen and pelvis and shows compression.

Duplex ultrasound: An ultrasound scan that shows both the structure of the veins and the direction and speed of blood flow. It is the usual first test for pelvic vein problems.
Dyspareunia: Pain during or after sex. A deep ache that lasts for hours after sex is a common symptom of pelvic congestion syndrome.

Embolisation (embolization): A minimally invasive procedure that blocks a faulty vein from the inside using coils, plugs, a foam or liquid sclerosant, or glue, so that blood drains through healthy veins instead.
Endometriosis: A condition where tissue similar to the womb lining grows outside the womb, causing pain and sometimes fertility problems. It is an important cause of pelvic pain to rule out or treat alongside venous causes.

Gonadal vein: The vein draining the ovary (ovarian vein) or testicle (testicular vein). The left one drains into the left kidney vein; the right one drains into the main body vein (inferior vena cava).

Iliac veins: The large veins carrying blood from the legs and pelvis up to the inferior vena cava. The internal iliac veins drain the pelvic organs.
Inferior vena cava (IVC): The largest vein in the body, carrying blood from the legs, pelvis and abdomen to the heart.
Interventional radiologist: A doctor who uses imaging such as X-ray and ultrasound to guide minimally invasive treatments through small tubes, including pelvic vein embolisation.

Left renal vein: The vein draining the left kidney. It crosses in front of the aorta, where it can be squeezed in nutcracker syndrome.

May-Thurner syndrome: Compression of the left common iliac vein by the right common iliac artery. It can cause leg swelling, blood clots and, in some people, pelvic vein reflux. Also called iliac vein compression syndrome.
MR venography: An MRI scan that shows the veins. It avoids X-ray radiation and gives detailed pictures of the pelvic organs as well.

Nutcracker syndrome: Compression of the left renal vein between the aorta and the superior mesenteric artery. It can cause blood in the urine, left flank pain and pelvic vein reflux.

Ovarian vein: The vein that drains blood from each ovary. Reflux in one or both ovarian veins is the most common finding in pelvic congestion syndrome.

Pampiniform plexus: The network of veins around the testicle (and, in women, near the ovary). When widened in men, it forms a varicocele.
Pelvic congestion syndrome (PCS): Long-term pelvic pain associated with widened, refluxing pelvic veins, usually worse after standing and better lying down.
Pelvic venous disorders (PeVD): The umbrella term doctors now use for conditions caused by abnormal veins in the abdomen and pelvis, including pelvic congestion syndrome, nutcracker and May-Thurner syndromes, and varicoceles.

Reflux (venous reflux): Blood flowing backwards in a vein, the wrong way, because valves do not close properly or flow is blocked further up.

Sclerosant: A medicine injected as a liquid or foam that irritates the vein lining so the vein seals shut.
Stent (venous stent): A flexible metal mesh tube placed inside a narrowed vein to hold it open, for example in May-Thurner syndrome.
SVP classification: A system published in 2021 by venous specialist societies to describe pelvic venous disorders by Symptoms, Varices and Pathophysiology. It helps doctors and researchers describe patients consistently.

Transvaginal ultrasound: An ultrasound scan using a slim probe placed in the vagina. It gives clear views of the pelvic veins, uterus and ovaries.

Varicocele: Widened veins around the testicle, caused by reflux in the testicular vein. It is the male equivalent of ovarian vein reflux.
Venogram (catheter venography): An X-ray test in which contrast dye is injected through a thin tube in a vein. It shows vein reflux and compression in detail and is usually done at the start of embolisation.
Vulval varicose veins (vulvar varicosities): Swollen, twisted veins on the vulva or upper inner thigh, common in pregnancy and sometimes caused by pelvic vein reflux.