This document discusses Superior vena cava syndrome (SVCS), which is caused by obstruction of the superior vena cava leading to symptoms like facial swelling and difficulty breathing. The document covers the history, anatomy, pathophysiology, clinical features, investigations, grading, and management of SVCS. It notes that while SVCS was once considered a medical emergency, it rarely causes immediate life-threatening issues now. Treatment depends on the underlying cause but may include supportive care, stents, chemotherapy, radiation therapy, or surgery. Radiation often provides symptom relief within 2 weeks for cancers like lung cancer.

1. Superior
vena cava
syndrome
DR AMIT P JOSE
DEPARTMENT OF PULMONARY
MEDICINE
AIMS, KOCHI

2. HISTORY

3. HISTORY
▪ First recorded description of SVC obstruction (SVCO) - 1757 when
William Hunter described the entity in a patient with a syphilitic
aortic aneurysm.
▪ For nearly two centuries- nonmalignant processes such as aortic
aneurysms, syphilitic aortitis, or chronic mediastinitis due to
tuberculosis were the predominant etiologic factors.
▪ Now Rare

4. ▪ In the preantibiotic era-
▪ syphilitic thoracic aortic aneurysms,
▪ fibrosing mediastinitis,
▪ untreated infection were frequent causes of the SVC syndrome.
▪ Subsequently, malignancy became the most common cause,
accounting for 90 percent of cases by the 1980s.
▪ More recently, the incidence of SVC syndrome due to thrombosis
has risen, largely because of increased use of intravascular
devices such as catheters and pacemakers.
▪ Benign causes now account for 20 to 40 percent of cases of SVC
syndrome.

5. ▪ Once considered a medical emergency.
▪ SVCO rarely experience immediate, life-threatening complications.

6. ANATOMY

7. ANATOMY
Left
Brachiocephalic
vein
Right
Brachiocephalic
vein
Superior
vena
cava

9. ▪ Behind the lower border of the first right costal cartilage.
▪ Azygos vein joins it just before it enters the right atrium, at the
upper right front portion of the heart.
▪ Distal 2 cm lying within the pericardial sac
▪ Formed by the joining of the internal jugular and subclavian veins.
▪ No valve divides the superior vena cava from the right atrium.
▪ As a result, the (right) atrial and (right) ventricular contractions are
conducted up into the internal jugular vein and, through the
sternocleidomastoid muscle, can be seen as the jugular venous
pressure.

11. SVC SYNDROME
▪ Constellation of signs and symptoms caused by obstruction of
blood flow in superior vena cava.
▪ External compression
▪ Invasion
▪ Constriction
▪ Thrombosis of SVC
▪ Partial or complete obstruction

12. Pathophysiology

13. Pathophysiology
▪ Right lung.
▪ Lymph nodes.
▪ Mediastinal structures.
▪ Thrombosis of blood within SVC.

14. ▪ Collateral veins may arise from the
azygos, internal mammary, lateral
thoracic, paraspinous, and esophageal
venous systems .
▪ The venous collaterals dilate over several
weeks.
▪ Upper body venous pressure is markedly
elevated initially but decreases over time.
▪ Symptoms and signs from SVC
obstruction depends upon the rate at
which complete obstruction of the SVC
occurs in relation to the recruitment of
venous collaterals.

15. ▪ Malignant disease- symptoms of SVC
syndrome within weeks to months- Rapid
tumor growth does not allow adequate
time to develop collateral flow.
▪ In contrast, fibrosing mediastinitis due to
an infection such as histoplasmosis may
not become symptomatic for years.
▪ Edema- Narrow the lumen of the nasal
passages and larynx, potentially
compromising the function of the larynx
or pharynx- Dyspnea, stridor, cough,
hoarseness, and dysphagia.
▪ Cerebral edema can also occur and lead
to cerebral ischemia, herniation, and
possibly death.

16. ▪ Cardiac output- diminished transiently by
acute SVC obstruction
▪ Within a few hours, blood return is
reestablished by increased venous
pressure and collaterals.
▪ Hemodynamic compromise, if present,
more often results from mass effect on
the heart than from SVC compression.

17. Malignancy
Fibrosing
mediastinitis
Pacemaker
wires
Post
radiation
fibrosis
Central
venous
catheters

18. Clinical features of SVC
Shortness of breath
Chest pain
Cough
Dysphagia

19. Increased
Venous
pressure
Edema of
head, neck,
arms and
upper chest
Dilated
veins on
chest
wall
Pleural/
pericardial
effusion
Cerebral
edema/
increased
IC pressure

20. Clinical features of SVC syndrome
SIGNS Frequency
Thoracic vein distension 70%
Neck vein Distension 60%
Facial swelling 45%
UE/ Trunk swellings 40%
Cyanosis 15%

21. Grading
Grade Category Incidence Definition
0 Asymptomatic 10 Radiographic superior vena cava
obstruction in the absence of
symptoms
1 Mild 25 Edema in head or neck (vascular
distention), cyanosis, plethora
2 Moderate 50
Edema in head or neck with functional impairment
(mild dysphagia, cough, mild or moderate impairment
of head, jaw or eyelid movements, visual disturbances
caused by ocular edema)
3 Severe 10
Mild or moderate cerebral edema (headache,
dizziness) or mild/moderate laryngeal edema or
diminished cardiac reserve (syncope after bending)
4 Life threatening 5
Significant cerebral edema (confusion, obtundation)
or significant laryngeal edema (stridor) or significant
hemodynamic compromise (syncope without
precipitating factors, hypotension, renal insufficiency)
5 Fatal <1 Death
J Thorac Oncol 2008; 3:811. Copyright © 2008 Lippincott Williams & Wilkins.

22. Why SVC
▪ Surrounded by rigid structures
▪ Thin walled easily Compressible
▪ Prone to obstruction

23. Consequence of SVCS
▪ Venous collaterals
▪ Severity of symptoms depends on time course of obstruction

24. Collaterals
▪ Thoracic venous collaterals:
▪ Azygos- hemiazygos- accessory hemiazygos system
▪ Vertebral and subscapular plexuses
▪ Mediastnal venous plexus and esophageal venous plexus and
diaphragmatic venous plexus
▪ Lateral thoracic and superficial thoracoabdominal venous plexus
▪ Abominal venous collaterals

25. INVESTIGATION

26. Radiologic
•CXR
•CT
•MRI
•USG
•Contrast
enhanced
venography
•Tc 99m scan
Histologic
•Bone marrow
biopsy
•Lymph node
biopsy
•Sputum/
pleural fluid
cytology
•Bronchoscopy
•Thoracentesis
•Thoracotomy

27. Chest Radiograph
▪ Mediastinal widening.
▪ Venous collaterals:Large Azygous vein
▪ Mediastinal/ hilar mass
▪ Pleural effusion
▪ Calcifications

28. Contrast enhanced chest CT
▪ Defines the level and extent of venous blockage.
▪ Identification of the underlying cause of venous obstruction.
▪ Identify and map collateral pathways of venous drainage
▪ Presence of collateral vessels on CT is a strong indicator of SVC
syndrome, Specificity of 96 percent and sensitivity of 92 percent.
▪ Contrast-enhanced blood from the collateral circulation draining
into the inferior vena cava can simulate the appearance of a liver
"hot spot" on CT

30. Venography
▪ Bilateral upper extremity venography is the gold standard for identification of SVC
obstruction and the extent of associated thrombus formation.
▪ Superior to CT for defining the site and extent of SVC obstruction and for visualizing
collateral pathways.
▪ It does not identify the cause of SVC obstruction unless thrombosis is the sole
etiology.
▪ Radionuclide technetium-99m venography to assess SVC patency and venous flow
patterns does not provide the important diagnostic information that is supplied by
chest CT.
▪ Helical CT with bilateral upper extremity contrast injection (helical CT phlebography)
appears to combine the diagnostic benefit of CT with the same degree of enhanced
vascular detail as digital venography, as long as appropriate techniques for
intravenous injection of contrast material are used to minimize flow artifacts arising
from unopacified blood.
▪ Neither approach is warranted unless an intervention (placement of an endovascular
stent, surgery) is planned.

32. MR venography
▪ Magnetic resonance venography (MRI) is an alternative approach
that may be useful for patients with contrast dye allergy or those
for whom venous access cannot be obtained for contrast
enhanced studies

33. Ultrasonography
▪ Exclusion of thrombus in upper extremity, axillary, subclavian, and
brachiocephalic veins.

34. Histologic diagnosis
▪ The clinical history combined with CT imaging will generally
differentiate between benign causes of SVC obstruction
(particularly caval thrombosis) and extrinsic compression related
to malignancy.
▪ Histologic diagnosis is a prerequisite for choosing appropriate
therapy for the patient with SVC syndrome associated with
malignancy.

35. TREATMENT

36. Medical
•Thrombolytics
•Anticoagulants
•Diuretics and
corticosteroids
Chemotherapy
•NHL
•Germ cell tumour
•Limited stage small cell
carcinoma
Radiation
•80-90 % relieved
Surgical treatment
•Bypass
Endovascular treatment
•Minimally invasive
•Thrombolysis,angioplasty,
stent placement

37. ▪ SVC syndrome associated with malignancy
▪ Alleviate symptoms and treat the underlying disease.
▪ The average life expectancy among patients who present with malignancy-associated SVC syndrome is
approximately six months.
▪ But there is wide variability depending on the underlying malignancy.
▪ Treatment of SVC syndrome and its underlying cause results in long-term relapse-free survival and cure.
▪ Most likely to be achieved in chemotherapy-sensitive malignancies using a combined modality treatment
approach.
▪ Evidence-based guidelines for management of SVC syndrome are not available.
▪ A general recommendation supporting radiotherapy or stent placement for symptomatic SVC syndrome
from lung cancer has been made by both the National Comprehensive Cancer Network (NCCN) and the
American College of Chest Physicians .
▪ Initial management should be guided by the severity of symptoms and the underlying malignant condition
as well as the anticipated response to treatment.

38. Need for emergent RT ??????
▪ Emergency RT is no longer considered necessary for most patients for several reasons:
▪ Symptomatic obstruction is often a prolonged process developing over a period of weeks or
longer prior to clinical presentation.
▪ Deferring therapy until a full diagnostic work-up has been completed does not pose a hazard
for most patients, provided the evaluation is efficient and the patient is clinically stable.
▪ illustrated in a review of 107 cases of SVC syndrome, in which no serious complication
resulted from the SVC obstruction itself or investigative procedures leading to the diagnosis
despite a prolonged period between the onset of symptoms and the initiation of therapy in
some cases.
▪ RT prior to biopsy may obscure the histologic diagnosis.
▪ One study of 19 patients with symptomatic mediastinal masses who received emergency RT,
a histologic diagnosis could not be established in eight (42 percent) from a biopsy obtained
after such treatment.
▪ Current management guidelines-accurate histologic diagnosis prior to starting therapy and
the upfront use of endovascular stents in severely symptomatic patients to provide more rapid
relief than can be achieved using RT.

39. Exception
▪ Patients who present with stridor due to
▪ central airway obstruction
▪ severe laryngeal edema, and
▪ those with coma from cerebral edema.
▪ These situations represent a true medical emergency, and these
patients require immediate treatment (stent placement and RT) to
decrease the risk of sudden respiratory failure and death.

40. Supportive care and medical management
▪ No data documenting the effectiveness of this maneuver, the head
should be raised to decrease hydrostatic pressure and head and
neck edema.
▪ Obstruction of blood flow through the SVC slows venous return.
This can result in local irritation or thrombosis of veins in the upper
extremities, or delayed absorption of drugs from the surrounding
tissues. Thus, the use of intramuscular injections in the arms
should be avoided.
▪ For patients who have obstruction of the SVC resulting from
intravascular thrombus associated with an indwelling catheter,
removal of the catheter is indicated, in conjunction with systemic
anticoagulation.

41. Glucocorticoids
▪ Two settings in which systemic administration of glucocorticoids
may be helpful.
▪ Symptomatology due to SVC syndrome caused by steroid-
responsive malignancies such as lymphoma or thymoma.
▪ In patients undergoing RT, particularly if laryngeal edema is
present, glucocorticoids are commonly prescribed to reduce
swelling.
▪ Only case reports to suggest benefit.

42. Diuretics
▪ Diuretics are also commonly recommended, although it is unclear
whether venous pressures distal to the obstruction are affected by
small changes in right atrial pressure.
▪ In a retrospective series of 107 patients with SVC syndrome from a
variety of causes, the rate of clinical improvement was similar
among patients receiving glucocorticoids, diuretics, or both

43. Chemotherapy for small cell lung cancer, NHL, and
germ cell tumors
▪ Initial chemotherapy is the treatment of choice for patients with symptomatic
SVC syndrome.
▪ Clinical response to chemotherapy alone is usually rapid.
▪ When chemotherapy is the initial intervention of choice and the SVC obstruction
is unrelieved, chemotherapy should be administered through a dorsal foot vein .
▪ Symptomatic improvement usually occurs within one to two weeks of treatment
initiation. In a review of treatment for SVC obstruction in patients with lung
cancer, chemotherapy alone relieved symptoms of SVC obstruction in 77
percent of those with SCLC, although 17 percent had a later recurrence.
▪ For these malignancies, use of RT alone usually yields poorer long-term results
and may compromise the subsequent results of chemotherapy .
▪ Certain situations (eg, limited stage SCLC, some subtypes of NHL), the addition
of RT to systemic chemotherapy may decrease local recurrence rates and
improve overall survival.

44. ▪ Among patients with SVC syndrome and NHL, symptoms
suggesting involvement of other mediastinal structures (eg,
dysphagia, hoarseness or stridor) and shorter symptom duration
appear to be adverse prognostic factors

45. Non-small cell lung cancer
▪ As compared with more therapy-sensitive malignancies, the degree and
rapidity of response to chemotherapy is less in NSCLC.
▪ Symptom relief in this setting is more rapidly achieved by the use of an
endovascular stent.
▪ SVC obstruction is a strong predictor of poor prognosis in patients with
NSCLC, with a median survival of only five months in one series.
▪ Long-term relapse-free survival has been rarely reported in patients with
locally advanced disease and SVC syndrome treated with chemotherapy
alone or a combined modality approach that includes both RT and
chemotherapy, therapy of SVC syndrome in patients with NSCLC is most
often directed toward palliation of symptoms rather than long-term
remission. For previously unirradiated patients, palliation is most often
achieved with external beam irradiation.

46. Radiation therapy
▪ Radiation therapy (RT) is widely advocated for SVC syndrome caused by radiosensitive tumors in patients who have not
been previously irradiated.
▪ Most of the malignancies causing SVC syndrome are radiation-sensitive, and at least in lung cancer, symptomatic
improvement is usually apparent within 72 hours.
▪ In a systematic review, RT was associated with complete relief of symptoms of SVC obstruction within two weeks in 78 and
63 percent of patients with SCLC and NSCLC, respectively.The rates of relapse post-treatment were 17 and 19 percent for
SCLC and NSCLC, respectively.
▪ Objective measurement of the change in vena caval obstruction may not parallel measures of symptomatic improvement.
▪ In an autopsy series,complete and partial SVC patency was found in only 14 and 10 percent of patients after RT for SVC
syndrome, despite reported relief of symptoms in 85 percent. These data have led some to suggest that the development of
collateralization may have contributed more to symptomatic improvement than the effect of RT, and to question the value
of urgent RT in patients with SVC syndrome from chemotherapy sensitive malignancies.
▪ Relief of symptoms may not be achieved for up to four weeks, and approximately 20 percent of patients do not obtain
symptomatic relief from RT. F
▪ urthermore, the benefits of RT are often temporary, with many patients developing recurrent symptoms before dying of the
underlying disease.
▪ Particularly if symptoms are severe, more rapid palliation can be achieved through the use of an intraluminal stent, followed
by RT for disease control. Stent placement is also effective in relieving symptoms in patients who fail to respond to RT.

47. Endovascular Stents
▪ Indications:
▪ Stent can be placed before a tissue diagnosis is available
▪ Useful procedure for patients with severe symptoms who require
urgent intervention.
▪ An endovascular stent is particularly appropriate for rapid
symptom palliation in patients with NSCLC and mesothelioma and
for those with recurrent disease who have previously received
systemic therapy or RT.
▪ The role of endovascular stenting in patients presenting with
chemotherapy sensitive tumors (ie, SCLC, NHL, germ cell tumors)
and SVC obstruction is uncertain.

48. ▪ Self-expanding endovascular stent restores venous return and provides
rapid and sustained symptom palliation in patients with SVC syndrome.
▪ The technical success rate is in the range of 95 to 100 percent, and over
90 percent of patients report relief of symptoms.
▪ The stent is placed percutaneously via the internal jugular, subclavian, or
femoral vein, under local anesthetic. A guide wire is manipulated through
the stenosis or obstruction in order to deploy the metal stent across the
lesion. One stent may not be sufficient to bridge the entire extent of the
stenotic area, particularly with involvement of the brachiocephalic veins.
Sometimes two or even three stents in series ("kissing stents").
▪ Total occlusion of the SVC is not necessarily a contraindication to
intraluminal stent placement nor is the presence of thrombus within a
stenotic area. In such cases, balloon angioplasty or catheter-directed
thrombolysis or mechanical thrombectomy could be considered prior to
stent placement.

49. ▪ There appears to be no significant difference in the published
outcomes of the three most commonly used stainless steel stents
(Gianturco Z stent, the Palmaz stent, or the Wallstent) .There are
newer self-expanding stents (Luminex, Smart, Protege) made from
nitinol (a nickel-titanium alloy) that exhibit shape memory effect
and superelasticity. They have some advantages over the first-
generation stents including a greater precision in placement within
a stenotic area, lower thrombogenicity, and a higher radial force
that allows them to withstand extrinsic compression and better
maintain long-term patency. Covered stents may have higher long-
term patency rates as compared to uncovered stents, but
additional experience is needed.

50. ▪ Systematic review of the literature of patients with SVC obstruction due
to lung cancer (either SCLC or NSCLC) .
▪ 159 patients who underwent stent placement, 95 percent had relief of
symptoms, and the incidence of reocclusion (usually due to thrombosis
or tumor ingrowth into the stent) was only 11 percent.
▪ In contrast, of the over 600 patients with SCLC, chemotherapy alone,
chemoradiotherapy, and RT resulted in complete or partial relief of
symptoms in 84, 94, and 78 percent of cases, respectively.
▪ Among 150 patients with NSCLC, approximately 60 percent had relief
with chemotherapy or RT. Overall, relapse rates were lower with SVC
stenting (11 versus 17 to 19 percent with RT and/or chemotherapy) in
both SCLC and NSCLC.

51. Thrombolytic therapy
▪ When extensive thrombosis occurs as a complication of SVC stenosis,
local catheter-directed thrombolytic therapy may be of value to reduce
the length of the obstruction and the number and length of stents
required, and also reduce the risk of embolization.
▪ The thrombus may also be removed by mechanical thrombectomy,
although this is used less often than thrombolysis.
▪ Thrombolytic therapy has also been administered following placement of
an endovascular stent in an attempt to decrease secondary reocclusion.
▪ Benefit of thrombolytics- unclear, and increase the risk of hematoma,
gastrointestinal hemorrhage, hemoptysis and epistaxis.
▪ In a systematic review, the morbidity of stent insertion was greatest
when thrombolytics were also administered, and there was no evidence
that reocclusion rates were lower . Thus, this approach is not generally
recommended.

52. Need for long-term anticoagulation ???????
▪ Short-term anticoagulation is often recommended after stent
placement but whether long-term anticoagulation is necessary is
an area of uncertainty.
▪ To prevent stent reocclusion, some advocate anticoagulation for
periods of one to nine months while others suggest antiplatelet
therapy alone.
▪ There are no data upon which to form an evidence-based
recommendation: warfarin 1 mg daily with the goal of maintaining
an INR of less than 1.6 is a reasonable approach.
▪ An alternative approach is dual antiplatelet therapy (eg,
clopidogrel 75 mg daily plus aspirin) for three months after stent
placement.

53. Complications of stent placement
▪ 3 to 7 percent of patients.
▪ Early complications include infection, pulmonary embolus, stent
migration, hematoma at the insertion site, bleeding, and rarely,
perforation or rupture of the SVC.
▪ Late complications include bleeding (1 to 14 percent) and death (1 to 2
percent) from anticoagulation and stent failure with reocclusion.
▪ Stent failure is most often caused by thrombus or tumor ingrowth.
▪ Most patients with malignancy-related SVC syndrome have a short life
expectancy, the stent usually remains patent until death.
▪ If reocclusion does occur, it can be treated with a second stent or
thrombolytic therapy, with good secondary patency rates.

54. Surgical intervention
▪ Surgical bypass is rarely performed in patients with malignant
cause of SVC syndrome because of the success of endovascular
stenting.
▪ Surgical management is more often undertaken in patients with
benign causes of SVC syndrome.
▪ One possible exception is malignant thymoma and thymic
carcinoma, which are relatively resistant to chemotherapy and
radiation.

56. Treatment
J Thorac Oncol 2008; 3:811. Copyright © 2008 Lippincott Williams & Wilkins.

57. Summary
▪ SVC syndrome results from extrinsic and intrinsic compression of
SVC
▪ Clinical presentation depends on acuity of obstruction and
adequate collateral development.
▪ Majority of svc due to malignancy
▪ Histologic diagnosis to guide treatment and determine prognosis.