Inferior vena cava syndrome (IVCS) is a very rare constellation of symptoms resulting from either an obstruction, or stenosis of the

inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of th ...

. It can be caused by physical invasion or compression by a pathological process or by

thrombosis Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (th ...

within the vein itself. It can also occur during

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ...

. Pregnancy leads to high venous pressure in the lower limbs, decreased blood return to the heart, decreased cardiac output due to obstruction of the inferior vena cava, sudden rise in venous pressure which can lead to placental separation, and a decrease in kidney function. All of these issues can arise from lying in the supine position during late pregnancy which can cause compression of the inferior vena cava by the uterus. Symptoms of late pregnancy inferior vena cava syndrome consist of intense pain in the right hand side, muscle twitching,

hypotension Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the di ...

, and fluid retention.

Signs and symptoms

IVCS presents with a wide variety of signs and symptoms, making it difficult to diagnose clinically. *

Edema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels tight, the area ma ...

of the lower extremities (peripheral edema), caused by an increase in the venous blood pressure. *

Tachycardia Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal ( ...

. This is caused by the decreased preload, decreased cardiac output, and leads to increased frequency. * In pregnant women, signs of fetal hypoxia and distress may be seen in the cardiotocography. This is caused by decreased perfusion of the uterus, resulting in

hypoxemia Hypoxemia is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia has many causes, and often causes hypoxia as the blood is not supplying enough oxygen to the tissues of the bod ...

of the fetus. * Supine hypotensive syndrome

Causes

the causes for this condition are the following: * Obstruction by

deep vein thrombosis Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and enla ...

or tumors (most commonly

renal cell carcinoma Renal cell carcinoma (RCC) is a kidney cancer that originates in the lining of the proximal convoluted tubule, a part of the very small tubes in the kidney that transport primary urine. RCC is the most common type of kidney cancer in adults, re ...

) * Compression through external pressure by neighbouring structures or tumors, either by significantly compressing the vein or by promoting

by causing turbulence by disturbing the blood flow. This is quite common during the third trimester of

when the

uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...

compresses the vein in the right side position. *

Iatrogenic Iatrogenesis is the causation of a disease, a harmful complication, or other ill effect by any medical activity, including diagnosis, intervention, error, or negligence. "Iatrogenic", ''Merriam-Webster.com'', Merriam-Webster, Inc., accessed 27 ...

causes may be suspected in patients with a medical history of

liver transplantion Liver transplantation or hepatic transplantation is the replacement of a diseased liver with the healthy liver from another person (allograft). Liver transplantation is a treatment option for end-stage liver disease and acute liver failure, a ...

, vascular catheters, dialysis and other invasive procedures in the vicinity * Budd-Chiari syndrome

Diagnosis

The diagnosis can be made clinically by observing the patient when in the right sided position where you can see multiple dilated veins over abdomen due to collaterals. Ultrasound with Doppler flow measurement may be used to assess the IVC and circulatory system.

Treatment

Treatment will vary depending on the cause of the vena cava compression or interruption. Often, treatment includes positional changes, avoidance of supine positioning, especially on the right side. In pregnancy, definitive management of the IVCS is to deliver the baby. In other conditions, medical or surgical treatment to remove or relieve the offending structure will relieve symptoms.

Frequency

Epidemiological data is elusive owing to the wide variety of clinical presentation. In the U.S., incidence is estimated to be at 5–10 cases per 100,000 per year. Minor compression of the inferior vena cava during

is a relatively common occurrence. It is seen most commonly when women lie on their back or right side. 90% of women lying in the supine position during pregnancy experience some form of inferior vena cava syndrome; however, not all of the women display symptoms.

References

External links

{{DEFAULTSORT:Inferior Vena Cava Syndrome Vascular diseases Paraneoplastic syndromes Syndromes affecting the cardiovascular system