Inferior vena cava syndrome (IVCS) is a result of obstruction of the inferior vena cava

Inferior vena cava

The inferior vena cava , also known as the posterior vena cava, is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart....

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

Thrombosis

Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...

 in the vein itself.

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.

Causes

• Obstruction by deep vein thrombosis
  Deep vein thrombosis
  Deep vein thrombosis is the formation of a blood clot in a deep vein. Deep vein thrombosis commonly affects the leg veins or the deep veins of the pelvis. Occasionally the veins of the arm are affected...
  
   or tumors (most commonly renal cell carcinoma
  Renal cell carcinoma
  Renal cell carcinoma is a kidney cancer that originates in the lining of the proximal convoluted tubule, the very small tubes in the kidney that filter the blood and remove waste products. RCC is the most common type of kidney cancer in adults, responsible for approximately 80% of cases...
  
  )
• Compression through external pressure by neighbouring structures or tumors, either by significantly compressing the vein or by promoting thrombosis
  Thrombosis
  Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
  
   by causing turbulence by disturbing the blood flow. This is quite common during the third trimester of pregnancy
  Pregnancy
  Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
  
   when the uterus
  Uterus
  The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
  
   compresses the vein in the right side position.
• Iatrogenic causes may be suspected in patients with a medical history of liver transplantion, vascular catheters, dialysis
  Dialysis
  In medicine, dialysis is a process for removing waste and excess water from the blood, and is primarily used to provide an artificial replacement for lost kidney function in people with renal failure...
  
   and other invasive procedures in the vicinity
• Budd-Chiari syndrome
  Budd-Chiari syndrome
  In medicine , Budd–Chiari syndrome is the clinical picture caused by occlusion of the hepatic veins. It presents with the classical triad of abdominal pain, ascites and hepatomegaly. Examples of occlusion include thrombosis of hepatic veins. The syndrome can be fulminant, acute, chronic, or...
  
  

Symptoms

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

• Edema
  Edema
  Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
  
   of the lower extremities
• Tachycardia
  Tachycardia
  Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
  
  
• In pregnant women, signs of fetal hypoxia and distress may be seen in the cardiotocography
  Cardiotocography
  In medicine , cardiotocography is a technical means of recording the fetal heartbeat and the uterine contractions during pregnancy, typically in the third trimester...