Superior vena cava syndrome

Superior vena cava syndrome (SVCS) is caused as consequence of restriction of blood flow in superior vena cava. Annual incidence is approximately 5/100 000. Most of the cases is caused by malignant tumors, usually lung cancer. Symptoms include edema of face, neck and upper limbs with often visible distended subcutaneous veins. Other frequent symptoms are shortness of breath, cough and opresson of other organs in mediastinum.

Pathophysiology


Syndrome is cause by reduced blood flow in superior vena cava. Usual cause is pressure on superior vena cava, but also other reasons can be thrombosis or tumor growing in wall of the vessel.

Common causes of reduced blood flow:
 * lung cancer (80 % of cases);
 * lymphoma;
 * embryonic tumours of medistinum;
 * metastasis to medisatinum;
 * iatrogenic cause: pacemaker electrode, central venous catheter;
 * infection: secondary mediastinal fibrosis;
 * benign mediastinal tumors;
 * medistinal fibrosis;
 * sarcoidosis;
 * aortic aneurysm.

Severity depends on hight of lesion and speed of defect development. Collateral vessels can be made when defect is slowly developing, therefore symptoms are less severe. When there is lesion under separation of v. azygos, symptoms are more severe, reason is that also collateral vessels are restricted.

Signs and symptoms


Edema of face, neck and upper limbs is characteristic sign. Usually distended vessels are also present. Aditionally edeme around eyes, subconjunctival hemorrhages, chest pains, headaches, epistaxis, tinnitus, dizziness, cyanosis and vocal cord paresis can be signs of SVCS.

Diagnosis
Clinical signs are so characteristic, that they are enough to make superior vena cava syndrome diagnosis. After finding of the primary cause is necessary. This can be done by using imaging techniques, that can picture tumor. Venography can be used when there is thrombosis is suspected.

Treatment
Basis of therapy is to solve primary cause. Symptomatic therapy includes corticoids and diuretics. This therapy can reduce edema around tumor.

Související články

 * Vena cava superior