Introduction:
Superior vena cava syndrome or SVCS refers to a group of signs and symptoms that is caused by the severe obstruction of the superior vena cava, known as SVC, which is a short and wide blood vessel that is known to carry and circulate the blood into the heart and eventually to the rest of the body. In the majority of superior vena cava syndrome, the cases of this disease are caused because of several malignant tumors, such as lung cancer, non-Hodgkin's lymphoma, non-malignant benign mediastinal tumors, and aortic aneurysm. Infections and fibrosing mediastinitis may cause the same as well.
A few of the characteristic features- edema or swelling because of excess fluid in the face and the arms, the development of swollen veins in the chest, shortness of breath, coughing, difficulty swallowing, headache, and stridor or a high-pitched wheeze with edema of the epiglottis, edema of the brain and severe neurological symptoms that compromise airway being amongst the fatal manifestations. The resolution of superior vena cava syndrome is directly proportional to the treatment and management of the underlying etiology.
What Is the Superior Vena Cava?
The heart has four chambers- two upper sections, the right and left atrium, and two lower sections, the right and left ventricles. Parallel to four chambers, the heart has four valves: mitral, tricuspid, aortic, and pulmonary. Valves are a crucial part of the heart’s structure. They open and close as the blood passes through them. They mainly regulate the entry and exit of blood into the various chambers of the heart. The valves have flaps or leaflets that open and close. Valves with three leaflets open and close simultaneously. In order to avoid any sort of backflow of blood, the leaflets close, and vice versa is why they open. The superior vena cava, or the SVC, is the larger of the two vena cava and is the greatest venous trunk that functions to return the deoxygenated blood from the circulatory system into the right atrium of the heart with a diameter of 24 mm (millimeters) that receives all the venous return from the upper section of the body, above the level of the diaphragm. In addition to this, the venous return from the lower section of the body and below the diaphragm flows within the inferior vena cava.
What Are the Signs and Symptoms of Superior Vena Cava Syndrome?
SVCS, or superior vena cava syndrome generally represents a more gradual increase and severity along with escalated symptoms over time as and when there is an increase in the malignancies’ size or invasiveness. Mentioned below are a few of the signs and symptoms of superior vena cava syndrome.
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Difficulty while breathing.
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Frequent headaches.
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Facial edema or swelling.
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Venous distention- neck, upper arm, chest.
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A sudden drop in lung capacity.
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Facial swelling while bending.
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Increased swelling while bending forward.
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Upper limb swelling.
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Frequent lightheadedness.
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Heavy cough.
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The collar of Stokes.
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Presence of the Emberton's sign.
What Are the Causes of Superior Vena Cava Syndrome?
More than half of the cases that have been diagnosed with superior vena cava syndrome are reported to have been caused because of the presence of malignant tumors that compress the superior vena cava. During lung cancer, even a small-sized carcinoma may lead to the development of this condition. Mentioned below are a few of the causative agents behind the formation and development of superior vena cava syndrome.
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Non-Hodgkin lymphoma.
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Diffuse large B-cell lymphoma.
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Rare malignant Hodgkin's lymphoma.
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Metastatic cancers.
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Leukemia (blood cancer).
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Leiomyosarcoma of the mediastinal vessels (a malignant tumor that arises from smooth muscle cells in the blood vessels within the chest cavity).
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Plasmocytoma (a localized tumor composed of abnormal plasma cells).
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Syphilis (a sexually transmitted infection caused by the bacterium Treponema pallidum).
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Tuberculosis (an infectious disease caused by the bacterium Mycobacterium tuberculosis, primarily affecting the lungs but can also affect other parts of the body).
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Invasion by a pathological process.
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Compression by a deep vein thrombosis.
How to Diagnose Superior Vena Cava Syndrome?
The main techniques for diagnosing superior vena cava syndrome are chest X-rays or CXR, CT scans or computed tomography scans, transbronchial needle aspiration, and mediastinoscopy. Chest X-rays are generally provided in order to check the ability to measure the mediastinal widening and thus may possibly reveal the primary reason for superior vena cava syndrome. It should be noted that a good amount of patients with superior vena cava syndrome may have a normal chest x-ray. The required CT scans must be precisely contrast-enhanced, and they must be taken of the chest, neck, chest, pelvis, and lower abdomen.
How to Treat Superior Vena Cava Syndrome?
There are several ways and methods for the treatment of superior vena cave syndrome. Drug therapy and careful surgery are the two major divisions for the management of this condition surgery. The symptoms get relieved to some extent with radiotherapy. Mentioned below are a few of the available treatment and management strategies for superior vena cava syndrome.
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Therapy with glucocorticoids like Prednisone and Methylprednisolone has the potential to drastically decrease the inflammatory response and the surrounding edema since they create a steroid response in tumors such as lymphoma.
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Diuretics such as Furosemide can be used to decrease the venous return to the cardiovascular system, which may then relieves the increased amount of pressure.
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Endovascular stenting.
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Bilevel positive airway pressure or BiPAP.
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Positive airway pressure that is continuous.
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Mechanical ventilation.
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Spontaneous respiration.
Conclusion
Superior vena cava syndrome is the obstruction of the superior vena cava that results in an immediate blockage of the flow of blood to the heart and out of the heart. This eventually leads to abruption in the normal circulatory system of the body. Shortness of breath and swelling of the face, along with swelling of the limbs, are the most common signs and symptoms that the patient presents with. Tumors that compress the superior vena cava are one of the highest reported causes of this condition. There are several diagnostic measures to evaluate the condition of the patient, with chest X-rays being the most simple and most valuable of them all. Treatment includes both medication therapy as well as surgical intervention. Radiotherapy does give relief to the disruptions caused by superior vena cava syndrome but only to some extent.
