2. Introduction
• Emergencies in patients with cancer may be classified into three
groups: Pressure or obstruction caused by a space-occupying lesion,
metabolic or hormonal problems (paraneoplastic syndromes) and
treatment-related complications.
• Superior vena cava syndrome (SVCS) is the clinical manifestation of
superior vena cava (SVC) obstruction, with severe reduction in venous
return from the head, neck, and upper extremities.
• Characteristic symptoms and signs may develop quickly or gradually
when this thin-walled vessel is compressed, invaded, or thrombosed
by processes in the superior mediastinum.
3. Malignant causes
1.Primary : Older age groups : NSCLC (most common)
SCLC (highest risk)
Younger age groups : Lymphoma (PMBL,T-
LBL,DLBCL)
Mediastinal Germ cell tumour.
2.Secondaries (Nodal metastasis) : Breast carcinoma
Benign Causes : Catheter induced, Behcet’s, TB,
Mediastinal fibrosis etc
4.
5. Malignancy is the most common cause of SVCS by and far .This can be
due to any of the following mechanisms :
1. Extrinsic compression of the vein in the superior mediastinum by the
tumour or mediastinal lymph nodes.
2. Direct intravenous infiltration by the tumour mass.
3. Procoagulant status in malignancy can enhance catheter related venous
thrombosis.
In some cases, both external compression and thrombosis coexist
6. Lung Cancers
• Because of their common presentation with bulky centrally located masses
involving the hila and mediastinum, small cell lung cancer (SCLC) and squamous
cell carcinoma are the most common histologic lung cancer subtypes responsible
for SVCS.
• In lung cancer patients, SVCS was present in up to 8.6% of the patients.
• In patients with stage III non–small-cell lung cancer (NSCLC), the presence of SVCS
has been reported to be a significant factor indicative of shorter survival.
• Risk of SVCS is highest with small cell lung ca ,but due to higher prevalence NSCLC
are the most common cause of svc.
7. Lymphomas
• Lymphoma involving the mediastinum is the cause of SVCS in 2% to 21% of
patients
• Most patients with SVCS have either diffuse large cell B lymphoma or
lymphoblastic lymphoma.
• Although Hodgkin lymphoma commonly involves the mediastinum, it rarely
causes SVCS.
• SVC syndrome is even more common in patients with primary mediastinal large
B-cell lymphoma with sclerosis, an unusual and aggressive NHL subtype that
represents 3 to 7 percent of all diffuse large cell lymphoma .
8. Although most NHLs cause SVC
syndrome by extrinsic
compression due to enlarged
lymph nodes , patients with
intravascular (angiotropic)
lymphoma have intravascular
occlusion as the primary
pathogenic mechanism
9. Other malignancies
• Breast cancer is the most common metastatic disease causing SVCS in up to 11%
of the cases.
• Other rare primary or metastatic mediastinal malignancies such as thymic
malignancies, pleural mesothelioma, sarcomas, and primary mediastinal germ
cell tumors may cause SVCS.
• The prognosis of patients with SVCS strongly correlates with the prognosis of the
underlying disease.
10. Non malignant aetiologies
• As many as 40% of patients have been reported to present with nonmalignant
SVCS, most commonly due to thrombosis due to the presence of central vein
catheters .
• Other rare nonmalignant causes of SVCS include inflammatory vascular
conditions that may be associated with an increased risk of thrombosis, such
as Behçet’s disease, vascular anomalies or aneurysms exerting pressure on
the SVC, and inflammatory mediastinal processes such as fibrosing
mediastinitis (a prior infection with Histoplasma capsulatum) or Castleman
disease.
• Other infections that have been associated with fibrosing mediastinitis include
tuberculosis, nocardiosis, actinomycosis, aspergillosis, blastomycosis, and
Bancroftian filariasis
11.
12. SUPERIOR VENACAVA ANATOMY
• The SVC is the major low-pressure vessel for drainage of venous blood from the head, neck, upper
extremities, and upper thorax
• It is located in the right superior mediastinum and is surrounded by the sternum, trachea, right
mainstem bronchus, aorta, pulmonary artery, and perihilar and paratracheal lymph nodes.
• The SVC extends from the junction of the right and left innominate veins to the right atrium, over
a distance of 6 cm to 8 cm. The distal 2 cm of the SVC are within the pericardial sac.
• The left and right brachiocephalic veins merge at the level of the aortic arch to form the SVC. The
brachiocephalic veins themselves receive contributions from the internal and external jugular
veins, subclavian veins, internal mammary veins, pericardiophrenic veins, superior intercostal
veins, and inferior thyroid vein.
• The azygos vein—the main auxiliary vessel—enters the SVC posteriorly, just above the pericardial
reflection. The physiologic width of the SVC is 1.5 cm to 2 cm.
13.
14. Anatomic
classification
of SVC
obstruction
includes 3
levels of
obstruction:
An obstruction proximal to the azygous vein causes the
blood to return to right atrium through the azygous
system and intercostal veins into the SVC
In SVC obstruction at the level of azygos, blood cannot
re-enter the SVC through the azygos system and is
forced to utilize other collateral veins, leading into the
inferior vena cava (IVC) and from there into the right
atrium- and symptoms are usually more severe
In SVC obstruction below the level of azygos vein, blood
will be redirected via azygos and hemiazygos system in
a retrograde manner ultimately to the IVC, hence
causing less severe symptoms
18. Clinical Presentation :
The presentation of SVC obstruction depends upon the
• Time course of SVC invasion or compression,
• The degree of luminal compromise, and
• Whether recruitment of venous collaterals has compensated for the narrowing.
While this often occurs over a protracted period, acute thrombosis of a prior stable
partial obstruction can also occur, leading to abrupt symptoms
19. Clinical features :
#Symptoms and signs may be aggravated by bending forward, stooping, or lying down.
Mild to Moderate symptoms
• Non pulsatile dilated veins
• Diffuse edema of upper limbs
and face
• Heaviness of head
Dyspnea
Severe symptoms
• Reduced C.O resulting in Heart
failure
• Massive pleural effusions (rt>lt)
• Seizures with significant cerebral
edema
• Visual disturbances
• Stridor
20. •Respiratory symptoms can be related to edema from
SVC syndrome, which can narrow the lumen of the
nasopharynx and larynx, causing dyspnea, stridor,
cough, hoarseness, and dysphagia.
• Respiratory distress can also be related to pleural
effusion or from pulmonary restriction from severe
chest or breast swelling .
•Severe manifestations of venous outflow obstruction
can reduce perfusion pressure, potentially leading to
ischemia and venous gangrene, limb loss, and even
death .
25. Management
• Older broad principle : Initiate radiotherapy immediately after diagnosis.
• The paradigm shift in management:
• Acute mortality owing to SVC syndrome is uncommon (0.3%)
• The clinical course of SVCS rarely represents an absolute emergency.
• Radiotherapy without confirming the tissue diagnosis in chemo-sensitive,
tumours is not useful.
• Biopsy after radiotherapy gives inaccurate tissue diagnosis and hampers
further management.
26. Investigations
• Initial imaging :
1. X Ray chest : The most common radiographic abnormalities seen
are superior mediastinal widening and pleural effusion.
2. Conventional venography:The limitation of invasive venography
is the inability, to evaluate the specific cause of extrinsic SVC
compression
3. Imaging of choice : CECT thorax
4. Venous doppler used as adjunct in minor cases.
27. • Tissue Diagnosis :
1. Ct guided core needle biopsy .If not possible, invasive procedures are used
(risk of tracheal collapse).
2. Endobronchial fine-needle aspiration, Mediastinoscopy, Thoracocentesis.
3. Thoracoscopic biopsy: It is diagnostic if all other procedures have failed
• Disease Staging :FDG PET CT
28. Ultrasound
• Ultrasound — The central vasculature offers several challenges to
ultrasonography. As compared with the peripheral vasculature, evaluation of the
central veins using ultrasonography is more indirect.
• Doppler is used to assess respiratory variations and waveforms while color
Doppler is used to assess flow and direction.
• Findings that suggest central venous occlusion include dampening of the
waveforms with loss of venous pulsatility and loss of respiratory variation.
• Typical manoeuvres used during peripheral ultrasonography such as venous
compression and other supportive manoeuvres are limited because of anatomic
constraints
29. CT –MRV
• Computed tomography — Both non-contrast and contrast-enhanced CT can
demonstrate overall size, position, and calcifications of the thoracic central
vasculature .
• CT or MR venography can define the level and extent of venous blockage, identify
and map collateral pathways of venous drainage, and often permit identification
of the underlying cause of venous obstruction.
• The presence of collateral vessels on CT is a strong indicator of SVC obstruction,
with a specificity of 96 percent and sensitivity of 92 percent
30. Conventional venography
• Conventional, catheter-based venography remains the gold standard
for vascular imaging though is rarely necessary for initial diagnosis .
• While CT or MR provides a broad picture, in addition to providing
visualization of stenosis, thrombus, and collateral pathways, catheter-
based venography provides real-time clinical information regarding
flow patterns and rates and better "resolution" of smaller vessels,
often with less contrast than less invasive modalities.
• Furthermore, catheter-based venography offers an opportunity to
treat any hemodynamically significant lesions.
• However, catheter-based venography does not image the surrounding
structures, and thus will not identify the specific cause of
31. Recommendations
• For patients who present with mild to moderate symptoms (edema, pain),
including suspected superior vena cava (SVC) syndrome (grade 0,1,2 with
or without a known malignancy, either a venous duplex study or cross-
sectional imaging (computed tomographic [CT] venography, magnetic
resonance [MR] venography) may be used as the initial study .
• Duplex ultrasound is useful for excluding thrombus in the subclavian,
axillary, and brachiocephalic veins and is the initial imaging study for
patients with mild-to-moderate symptoms who present with extremity
swelling and who have an indwelling device, or those with a known
malignancy at low risk to cause venous obstruction. Additional imaging
studies may be needed depending upon the suspected etiology.
32. •Severe symptoms — For patients with severe or life-
threatening symptoms (e.g., severe acute primary
venous thrombosis, grade 3,4 SVC syndrome (table 1),
cross-sectional imaging with either CT or MR
venography is typically recommended as the initial
imaging modality to establish the diagnosis and for
surgical planning, depending upon the clinical
scenario and availability of institutional resources.
33. During the Diagnostic process :
• Supplemental oxygen
• Head end elevation (as high as tolerated)
• Diuretics (carefully assessing the hemodynamic status )
• Salt restricted diet (SRD)
*The use of upper extremities to deliver injectables should be avoided
34. Role of Steroids
• Steroids:They should only be considered after pathologic
confirmation of the cause of SVCS in symptomatic patients who
require urgent palliation, as steroid initiation prior to pathologic
confirmation can significantly hamper efforts for an accurate
diagnosis, especially with lymphomas.
• For patients receiving RT on an emergency basis -a short course of
high-dose corticosteroids is suggested to minimize the risk of central
airway obstruction secondary to edema .
35. • The goal of SVCS treatment depends on the cause, and in
malignancies, it depends on the stage of the disease.
• Malignant tumors are potentially curable if they present at
a non-metastatic stage, even in the presence of SVCS.
• The treatment of SVCS should be selected according to the
underlying histology and stage of the primary process.
36. SUPERIOR VENACAVA SYNDROME
Immediate
endovascular
procedure to
relieve obstruction
Grade 3 and lower
symptoms with no life
threatening signs.
Oxygen
Low salt diet
Head end elevation
Diuretics
Malignant(Metast
atic vs local)
Benign
,treat
underlying
cause.
Curative intent
(Multimodality
CT /RT)
Palliative
intent –RT
/Stent
Life threatening
symptoms
Cardiac failure, Stridor,
significant cerebral
edema
Diagnostic evaluation,
FDG PET, Tissue
Diagnosis.
38. “When the therapeutic goal is only palliation of SVCS or
when urgent treatment of the venous obstruction is required,
direct opening of the occlusion should be considered.
Endovascular stenting and angioplasty with possible
thrombolysis may provide prompt relief of symptoms before
more cancer-specific therapy”
39. Managing a thrombus :
• Thrombolysis : Mechanical > Pharmacological.
Anti coagulation based on Khorana score after thrombolysis and anti
platelets after stenting for 2 to 3 months to prevent stent thrombosis.
• Thrombolysis is often an integral part of the endovascular
management of SVCS, because thrombosis is frequently a critical
component of the obstruction and lysis is necessary to allow the
passage of the wire. Most reports have emphasized the use of
combination endovascular therapy: thrombolysis, angioplasty, and
stent insertion.
40.
41.
42. SMALL-CELL LUNG CANCER
• Platinum-based chemotherapy alone or in combination with thoracic
RT is the standard treatment for SCLC and is effective in rapidly
improving the symptoms of SVCS.
• No significant difference in response rates to chemotherapy or RT has
been detected in most studies.
• However, upfront RT in combination with chemotherapy may be
associated with better overall survival, suggesting that optimal local
control matters. Relief of SVCS typically occurs within 7 to 10 days
after initiation of therapy.
43. NON–SMALL-CELL LUNG CANCER
• A review of SVCS in lung cancer indicated that chemotherapy relieved
SVCS in 59% of patients with NSCLC; RT relieved the obstruction in
63% of patients with NSCLC.
• Nevertheless, in almost 20% of the patients, the obstruction recurred.
Response to RT was higher in patients who had received prior therapy
(94% vs 70%), suggesting that RT is an effective salvage option even in
recurrent SVCS.
44. NON-HODGKIN LYMPHOMA
• The primary treatment for non-Hodgkin lymphoma is chemotherapy,
as it has both local and systemic activity.
• Local consolidation with RT is beneficial in patients with early-stage,
diffuse, large-cell lymphoma, particularly if the mass is bulky.
• In a report of 36 patients with SVCS secondary to non-Hodgkin
lymphoma, all patients achieved complete relief of SVCS symptoms
within 2 weeks of the onset of any type of treatment, whether
treated with chemotherapy alone, chemoradiation, or RT alone.
45. Radiotherapy :
• The primary effect of palliative RT is achieved by shrinking the
underlying compressive/invasive malignant masses, thus decreasing
the extrinsic pressure on the SVC.
• For lymphomas, daily fractions of 1.8 to 2 Gy are recommended. For
lung cancers, standard palliative fractions of 3 to 4 Gy per fraction are
commonly used.
• In the absence of distant metastatic disease, the RT course may be
extended to a definitive treatment course, in combination with
sequential or concurrent chemotherapy when feasible.
46. • In the definitive treatment setting, the radiation field should encompass
all gross disease with appropriate margins for clinical and planning
target volumes.
• The total prescription dose of definitive RT is determined by the
underlying histology and matching standard of care.
• In the palliative setting, the RT field should encompass all gross disease
responsible for the SVCS, which may include the hilar, mediastinal, and
supraclavicular lymph nodes.
• Elective nodal irradiation is generally not recommended when treating
patients with lymphoma or lung cancer.
47. • Percutaneous transluminal angioplasty using balloon dilatation,
insertion of expandable metal stents, or both has been used successfully
to open and maintain the patency of SVC obstruction resulting from
malignant and benign causes.
• It is an effective and safe initial treatment for obtaining immediate relief
of the obstruction if the clinical status of the patient is rapidly
deteriorating.
48. Surgery
• In malignancy-induced SVCS, the tumor involvement causing SVCS is typically so
extensive that it is not considered technically resectable.
• There may be exceptions in which definitive surgical resection may be considered if
feasible (e.g., in a young, fit patient with a non-lymphomatous, nonmetastatic diagnosis
of malignancy & Residual mass after treatment for germ cell tumor) .
• In most cases, however, palliative surgical intervention should be considered only after
other therapeutic maneuvers such as RT, chemotherapy, and stenting have been
exhausted.
• The most common surgical approach is via a sternotomy or thoracotomy with extensive
resection of the tumor and reconstruction of the SVC.
49. SVC RECONSTRUCTION
• SVC reconstruction using grafts such as expanded polytetrafluoroethylene has become
possible with modern surgical techniques.
• There is also growing experience with direct bypass grafts for SVC obstruction.
• The preferred bypass route is between an innominate or jugular vein on the left side and
the right atrial appendage, using an end-to-end anastomosis.
50. SUMMARY OF TREATMENT:
• In patients with suspected underlying malignancy as the cause of SVCS who present with non–life-
threatening symptoms, an efficient diagnostic effort should be attempted before any oncologic treatment
is given.
• After the cause of SVCS has been established, treatment of the primary process should promptly follow.
• Combination of systemic therapy and RT is the treatment of choice for most NSCLC, SCLC, and
lymphomas.
• RT of the lesion and adjacent nodal areas results in optimal local control.
• Updated CT scanning and [18F]-fluorodeoxyglucose positron emission tomography imaging should be
incorporated into any carefully designed definitive RT treatment plan.
• Percutaneous endovascular intervention should be considered in severe cases because it relieves
symptoms rapidly without masking the diagnosis.
• Significant progress has been made in endovascular stent placement, with high rates of technical success
and low restenosis and complication rates.
• These endovascular techniques are optimally combined with histology-specific oncologic treatments for
durable local control.
51. • It emphasizes that in most patients (>85%) with SVCS, the symptoms are
not severe (grades 0, 1, and 2) and cancer-specific treatment could follow
appropriate diagnosis and staging.
• . Grade 3 (severe) patients who present with mild or moderate cerebral
edema, mild or moderate laryngeal edema, or diminished cardiac reserve
may be considered for immediate stent intervention or early RT;
otherwise, they should receive disease-specific treatment.
• Only the rare (<5%) grade 4 (life-threatening) patients who develop
significant cerebral edema or laryngeal edema with stridor or have
significant hemodynamic compromise should undergo stent insertion
immediately.
• Most experts recommend anticoagulation after thrombolysis (to prevent
disease progression and recurrence) and aspirin after stent placement in
the absence of thrombosis, but data are limited.
