Overview
The superior vena cava (SVC) is the second largest vein in your body, carrying deoxygenated blood from the upper half of your body to the right atrium, which is one of the four chambers in your heart. SVC obstruction occurs when the vein becomes narrowed or blocked. SVC obtruction can occur in chest tumours or enlarged lymph nodes, leading to external compression of the SVC. The obstruction may be a chronic condition, meaning it lasts for a long time, or it may be acute, meaning the condition starts suddenly and lasts for a short time.
In most cases, the cause of the obstruction is cancer, particularly lung cancer, although not all of the possible causes are cancerous.
Symptoms
The main symptom is shortness of breath. Other symptoms include a cough, headaches, swelling of the face, neck or arms, and swelling of veins in the neck, chest or arms.
Diagnosis
A doctor can diagnose the condition using imaging techniques, such as contrast-enhanced CT, MRI or a technique called a digital subtraction angiography.
Treatment
If the obstruction in the vein is caused by cancer, it is usually treated with radiation therapy and chemotherapy. However, it may take several weeks for the patient to respond to these treatments.
SVC stenting is a safe and effective procedure in which an interventional radiologist places a metal stent into the narrowed or blocked vein to hold it open. It is a minimally invasive option which can be carried out as a stand-alone procedure or in addition to other treatments. SVC stenting can be performed under general anaesthesia or mild sedation. A stent is a tube woven of thin metal wires. Stents are available in different length and sizes. By access via a vein in the groin or neck, a plastic tube called a catheter and a thin wire are used to pass the narrowing of the vessel. Afterwards, a stent is positioned under fluoroscopic guidance. Sometimes the stent has to be pushed to vessel wall by using a small balloon which is inflated inside the stent. In case of long stenosis two or more stents are positioned to bypass vessel narrowing In most cases, symptoms will clear up quickly following the stent placement, usually within 24 to 48 hours. Theain procedure risks are stent migration to the right heart, stent defect, and obturation of the SVC.