Superior Vena Cava Syndrome
What is Superior Vena Cava Syndrome?
The blood flow when stuck due to obstruction occur in Superior Vena Cava is termed as Superior Vena Cava Syndrome. This condition is indication of thorax malignancy and need immediate medical diagnostic assessment to detection of the underlying cause. This assists to plan for the further treatment plan. The Superior Vena Cava Syndrome requires emergency medical assistance. (1)
Pathophysiology
The supeior vana cava transmits almost one third of the venous return from upper part of the body including head, arm upper trunk to the heart. The pathophysiology of Superior Vena Cava Syndrome involves clotting in the anterior or middle mediastinum. The generation of thrombosis in superior vena cava may or may not involve extrinsic compression.
The thrombus formation in the superior vena cava leads to the utilization of a collateral vascular network of the lower body parts and also involved inferior vena cava. The sudden flow load increase in cervical venous pressure almost 20 mm Hg. This increase in pressure occurs due to the diameter of collateral vascular network and inferior vena cava is narrower than the venous return volume. (2,3)
Causes
The secondary complication of infection can lead to the supeior vana cava syndrome. The included infections are syphilitic aortic aneurysm or tuberculosis. Thrombus formation is the main cause of supeior vana cava syndrome.
In recent findings support that malignancy which provides the extrinsic mass effect due to invasive or venous intima.
The other considerable factors causes SVC syndrome are lung, breast and mediastinal neoplasms. Among these one of the prime cause is adenocarcinoma of the lung for development of SVC syndrome . Tumor development in the chest cavity which obstruct blood flow through SVC. Malignancy in the lymph nodes present surrounding parts of the SVC. Abrupt thrombotic event even a major cause of SVC syndrome. (3)
Signs & symptoms
The clinical signs of SVC syndrome include edema (fluid retention) and retrograde flow.
The commonly developed symptoms in SVCS are as follows:
- Breathing difficulty
- severe coughing
- Puffiness on the neck, face, arms and upper body.
Other than these, the following symptoms can also feel some affected individuals
- Huskiness
- Pain in chest
- Difficulty in deglutition
- Blood excreted from the throat or lungs during coughing
- Chest veins and neck veins become inflamed
- Fluid retention in the arms
- Breathing rate become rapid
- Cyanosis due to lack of oxygen supply
- Speech difficulty due to vocal cord paralysis
- Pupil of the eye becomes constricted, drooping eyelid and less perspiration on one side of the face due to Horner’s syndrome.
The severity of the symptoms depends upon how fast blockage develops. If the thrombus formation is moderate to mild and slowly obstruct the blood flows, then symptoms are milder and in case of fast developed obstruction leads to sudden outbreaks of severe symptoms. (2)
Diagnosis
The clinical presentation is one of the prime, but initial detecting rather suspecting criteria. This does not provide any confirmation of the presence of SVC syndrome.
The included different confirmatory tests are plain radiography, venography and CT scan (computed tomography). These tests do not only confirm the presence of disease, but it also helps to detect the location of the thrombus.
A tissue diagnosis need to conduct for detection of underlying cause. Sputum analysis, cytological investigation, bronchoscopy thoracocentesis and needle aspiration are different tissue diagnostic methods. (3,4)
Treatment
The treatment plan is made depending upon the underlying cause.
Cancer related Superior Vena Cava Syndrome is treated with chemotherapy and radiation may be single therapy or combination of both to reduce the size of the tumor that is responsible to create an obstruction.
Certain adjuvant therapies such as corticosteroids, anticoagulants, thrombolytics and diuretics may incorporate in the treatment plan depending upon the patient’s physiological condition.
Currently fibrinolytic therapy with urokinase and endovascular treatment via intraclot infusion are recommended for thrombolysis and anticoagulation.
Endo vascular surgery can be conducted by stenting and/or angioplasty.
Surgical bypassing of the obstruction assists with continuous blood flow, but the process is may not apply for all the cases. The obstruction of the blood flow has some technical difficulty and indicate may not applicable practically for all the cases; which depends on the site of thrombus formation.
In certain cases, compression and dilation are considered as reconstructive surgery and provide good outcome for malignancy.
Percutaneous stent placement is an uncomplicated, safe and effective measure for malignant cells.
Other than therapeutic measures, some overall patient management technique like uplifting the top or head positioning of the patient’s bed can helpful process. (3,4)
Prognosis
The treatment specific prognosis depends upon the underlying cause of the patient, but radiation therapy or stenting provide good outcome. (4)
References
- Todd A Nickloes (2015); Superior Vena Cava Syndrome; Retrieve from: http://emedicine.medscape.com/article/460865-overview
- Superior Vena Cava Syndrome; Cancer. Net; Retrieve from: http://www.cancer.net/navigating-cancer-care/side-effects/superior-vena-cava-syndrome
- Ronny Cohen, Derrick Mena, Roger Carbajal-Mendoza, Ninon Matos, Nishu Karki; Superior vena cava syndrome: A medical emergency?; Int J Angiol. 2008 Spring; 17(1): 43–46; PMCID: PMC2728369; Retrieve from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2728369/
- Dr. Nick Imm (2014); Superior Vena Cava Obstruction; Retrieve from: http://patient.info/doctor/superior-vena-cava-obstruction
