|
This section has been reviewed and approved by the PLWC Editorial
Board, 02/05
Superior vena cava syndrome (SVCS) is a
collection of symptoms caused by the partial blockage or compression of
the superior vena cava, the major vein that carries blood from the head,
neck, upper chest, and arms to the heart. Nearly 95% of SVCS cases are
caused by cancer.
Causes
The superior vena cava, which drains into the right atrium of the heart,
can become compressed when a tumor growing inside the chest presses on
the vein. The most likely cancers to cause SVCS are lung cancer (especially
small cell lung cancer), squamous cell lung
cancer, adenocarcinoma
of the lung, non-Hodgkin lymphoma, large cell lung cancer, and other
cancers that spread to the chest. In some cases, a tumor originally
outside the superior vena cava may actually grow into, or invade, the
vein causing a blockage. Because the superior vena cava lies close to a
number of lymph nodes, any cancer that spreads to these lymph nodes,
causing them to enlarge, can also cause SVCS. Enlarged lymph nodes
compress the vein, which slows the blood flow and may ultimately result
in complete blockage. A less common cause of SVCS is a thrombosis (blood
clot) in the vein caused by an intravenous catheter or a pacemaker wire.
Symptoms
Symptoms usually develop slowly and include difficulty breathing
or shortness of breath, coughing, and swelling of the face, neck,
upper body, and arms. Rarely, patients may experience hoarseness, chest
pain, difficulty swallowing, and coughing
up blood.
Severe symptoms that are rarely seen include swelling of the veins in the
chest and neck, fluid collection in the arms and face, and accelerated
breathing. In severe cases, the skin may turn blue due to cyanosis (lack
of oxygen). Also, in rare instances, the patient may experience paralysis
of the vocal cords, and/or Horner's syndrome, characterized by a
constricted pupil, sagging eyelid, and the absence of sweat on only one
side of the face. SVCS can progress quickly to completely block the
trachea (airway). When this occurs, a ventilator may be needed to help
the patient breath until the obstruction can be treated. More commonly,
if the blockage develops slowly, other veins may enlarge to carry extra
blood and symptoms may be milder.
Diagnosis and treatment
Indications of SVCS can be seen with a chest x-ray and other imaging
techniques, such as chest computerized tomography (CT) scan or magnetic
resonance imaging (MRI). However, these tests are not diagnostic. If
symptoms are mild, the trachea is not blocked, and there is good blood
flow through other veins in the chest, treatment may not begin until a
clear diagnosis is made, or treatment may not be necessary at all. In
most cases, SVCS is managed by treating the underlying cancer with
chemotherapy or radiation treatment directed at the mass causing the blockage.
Other short-term treatments, aimed at reducing symptoms, include raising
the patient’s head, giving corticosteriods to
reduce swelling, or using diuretics to eliminate excess fluid from the
body. Less often, SVCS may be treated with thrombolysis
(treatment to break up a blot clot in the vein), stent
placement (a tube-like device inserted into the blocked area of the vein
to allow blood to pass through), or surgery (to bypass a blockage caused
by cancer).
Patient considerations
Because SVCS can cause serious breathing difficulties, it is considered
an emergency. Patients and their families should learn about potential
symptoms of SVCS and immediately report any symptoms to their doctor.
Even though SVCS is serious and its symptoms can be frightening, it is
successfully treated in most people.
SVCS in children
SVCS in children can be life threatening. Because a child's trachea is
smaller and softer than an adult's, it can quickly swell or be squeezed
shut causing breathing problems. Common SVCS symptoms in children are
similar to those in adults and may include coughing, hoarseness,
difficulty breathing, and chest pain. Fortunately, SVCS is rare in
children, occurring in about 12% of children with cancer in the chest.
Back
to Top
|
