Everything latest about SVCO.

1. SUPERIOR VENA CAVA SYNDROME

2. INTRODUCTION
• Superior vena cava syndrome (SVCS) is
obstruction of blood flow through the
superior vena cava (SVC).
• William Hunter first described the syndrome
in 1757 in a patient with syphilitic aortic
aneurysm.

3. •Anatomy
•Pathophysiology
•Etiology
•Clinical features
•Investigations
•Treatment

4. Anatomy
• Thin walled.
• Low pressure vessel.
• Drainage of venous
blood from upper
half of body.
• 7cm in length.
• 20-22mm in
diameter.

5. COLLATERALS
• There are four possible collateral systems
which were first described in 1949 by
McIntire and Sykes.
1.Azygos venous system.
2.Internal thoracic venous system.
3.Vertebral venous system.
4.External thoracic venous system.

6. Pathophysiology
• Pathogenetic basis of SVCS is obstruction to the blood flow.
• It can result from intrinsic or extrinsic obstacles.
– Intrinsic-thrombosis or invading tissue(uncommon).
– Extrinsic factors- compression or stricture of the vein.
• When obstruction of the SVC occurs,
– Vascular resistances rise and the venous return decreases.
– SVC pressure increases consistently.
– SVC with significant stenosis- collateral circulation opens up to
bypass the obstruction and restore the venous return.

7. Obstruction of upper SVC, proximal to Azygos entry point.

8. Obstruction with Azygos involvement

9. Obstruction of lower SVC, distal to Azygos entry point.

10. • The timing of the obstruction development is
important for its clinical implications.
– In acute impairments, the blood flow is not rapidly
distributed through the collateral network so
symptoms arise markedly.
– In the case of slow-growing diseases, the collateral
venous network has enough time to expand in
order to receive the circulating volume.
• For this reason, long-lasting, severe SVC obstruction can
sometimes be found without significant symptoms.

11. Etiology
• Previously infectious diseases used to be common
cause SVCS.
• Infections, such as Tuberculosis, Syphilis,
Histoplasmosis and Actinomycosis.
• Consistent decrease because of:
– Antibacterial therapies
– Improved social conditions.

12. • Benign
– Chronic mediastinitis.
– Catheter-induced Thrombosis.
– Aortic aneurysm
– Retrosternal goiter
– Pericardial, thymic, bronchogenic cysts.
– Lymphadenopaties.

13. • Malignant
– Non-small cell lung cancer(NSCLC):50%
– Small cell lung cancer(SCLC): 22%
– Lymphoma: 12%
– Mets:9%
– Germ cell tumors:3%
– Thymoma:2%
• Presently, Malignancies are predominant (95%) cause of SVCS.
Wilson L et al., NEJM 2007

14. • Incidence of Iatrogenic SVCS is currently
increasing.
• Pacemaker and defibrillator placement .
• Thrombosis related to the presence of central vein
catheters
McCurdy M et al., Crit Care Med 2012

15. Classification of SVCS
There are three main classification proposals which follow different methods of categorization.
• Doty and Standford’s classification (anatomical)
– Type I: stenosis of up to 90% of the supra-azygos SVC
– Type II: stenosis of more than 90% of the supraazygos SVC
– Type III: complete occlusion of SVC with azygos reverse blood flow
– Type IV: complete occlusion of SVC with the involvement of the major tributaries and azygos
vein
• Yu’s classification (clinical)
– Grade 0: asymptomatic (imaging evidence of SVC obstruction)
– Grade 1: mild (plethora, cyanosis, head and neck edema)
– Grade 2: moderate (grade 1 evidence + functional impairment)
– Grade 3: severe (mild/moderate cerebral or laryngeal edema, limited cardiac reserve)
– Grade 4: life-threatening (significant cerebral or laryngeal edema, cardiac failure)
– Grade 5: fatal
• Bigsby’s classification (operative risk)
– The low risk patients present:
• No dyspnea at rest,
• No facial cyanosis in the upright position,
• No change of dyspnea and No worsening of facial edema and Cyanosis, during the
supine position.
– The high risk patients present facial cyanosis or dyspnea at rest in the sitting position.

16. Doty and Standford’s
classification (anatomical)
• Type I: Stenosis of up to
90% of the supra-azygos
SVC
• Type II: Stenosis of more
than 90% of the supra-
azygos SVC
• Type III: Complete
occlusion of SVC with
azygos reverse blood flow
• Type IV: Complete
occlusion of SVC with the
involvement of the major
tributaries and azygos
vein

17. • The clinical seriousness is related to:
1.Level of obstruction and rapidity of development,
determining the effectiveness of collateral
circulation.
2. Involvement of other mediastinal structures
(compression or invasion of heart, pulmonary artery
and central airways, phrenic nerve paralysis)
Clinical presentation

18. • The clinical signs of this condition are mainly
represented by
– Cyanosis (due to venous stasis with normal arterial
oxygenation) and
– Edema of the upper chest, arms, neck and face (periorbital
initially).
• Swelling is usually more important on the right side,
because of the better possibility of collateral circulation
in the left brachiocephalic vein compared to the
contralateral.
• Other signs or symptoms are: 1. Coughing, 2. Epistaxis,
3. Hemoptysis, 4. Dysphagia, 5. Dysphonia and 6.
Hoarseness (caused by vocal cord congestion), 7.
Esophageal, Retinal and Conjuntival bleeding.

19. • In the case of significant cephalic venous stasis—
1.Headache- a common symptom and it is usually continuous
and pressing, exacerbated by coughing.
2. Dizziness,
3. Buzzing,
4. Drowsiness,
5. Stupor, Lethargy and even coma may be encountered.
• Dyspnea can be directly related to
1.Mediastinal mass or
2. Pleural effusion or
3. Cardiocirculatory impairment.
• Supine position may worsen the symptoms.

20. • Yu’s classification (clinical)
– Grade 0: Asymptomatic (Radiological SVC obstruction in
the absence of symptoms)
– Grade 1: Mild (Edema in head or neck, cyanosis, plethora)
– Grade 2: Moderate (Edema in head or neck with functional
impairment)
– Grade 3: Severe (mild/moderate cerebral or laryngeal
edema, limited cardiac reserve)
– Grade 4: Life-threatening (significant cerebral or laryngeal
edema, cardiac failure)
– Grade 5: Fatal

21. Diagnosis
• Physical examination is often crucial:
– Presence of edema and superficial venous network of
the upper chest may support the clinical diagnosis.
• Imaging studies are however required.

22. • Chest X ray -The most common radiological
findings are superior mediastinal widening
and pleural effusion.

23. • CECT is the most useful tool in the evaluation of the
mediastinal syndromes.
– Assess level of obstruction.
– Differentiate between thrombosis and tumor.
– Differentiate between compression and infiltration.
• The contrast flow can also help to distinguish the extent of the
collateral network.

24. • Invasive venography –
– Now rarely used due to the huge improvement in
vascular CT imaging.
– It is currently performed only as a preliminary to
operative procedures such as stent placement.
• Recently FDG-PETCT has gained an important
role.

25. • The histological diagnosis remains the key factor
for the causative treatment, in the case of
neoplastic etiology.
• It is necessary to have histological confirmation
before starting treatment.
• Pathologic confirmation of a thoracic malignancy
can be obtained as a cytologic specimen via
– Endobronchial fine needle aspiration
– Mediastinoscopy
– CT-guided needle biopsy

26. • Mediastinoscopy has a very high success rate and
low complication rate.(5%)
• Percutaneous transthoracic CT-guided fine
needle biopsy is an effective and safe alternative
to an open biopsy or mediastinoscopy.
• Thoracocentesis-In presence of a pleural
effusion, can establish the diagnosis of
malignancy in 71% of patients.
• Thoracoscopic biopsy or Thoracotomy is
diagnostic if all other procedures have failed.

27. Treatment
• Treatment depends on
1. Severity of symptoms.
2. Etiology.
3. Prognosis.
• Goals
– Relieve symptoms.
– Attempt cure of the primary malignant process.

28. Supportive Care:
– Elevation of head end of bed to decrease the
hydrostatic pressure and thereby the edema.
– Oxygen
– Diuretics- reduce cerebral edema.
– Glucocorticoids reduce the tumor burden in
Lymphoma and Thymoma- likely to reduce the
obstruction.

29. • Only a small percentage of patients with
rapid-onset obstruction of the superior vena
cava (SVC) are at risk for life-threatening
complications.
• Emergency treatment is indicated with
– Central airway compromise.
– Severe laryngeal edema.
– Coma secondary to cerebral edema.

30. • Chemotherapy indicated in
– Lymphomas.
– Germ cell tumors.
– Small cell lung cancer.

32. • A Cochrane systematic review concluded that
chemotherapy and radiotherapy were equally
effective at relieving SVCO secondary to lung
cancer, where as stent insertion provided
higher rates of response more rapidly.
(Rowell and Gleeson, 2001).

34. Endovascular stents
• The placement of an endovascular stent restores
venous return and provides rapid and sustained
symptomatic relief.
• The technical success rate is in the range of 95 to 100%,
and over 90% of patients report relief of symptoms.
• Indications –
– It is a useful procedure for pts with severe symptoms (eg,
stridor) who require urgent intervention.
– Can be placed before a tissue diagnosis is available
– For rapid symptom palliation in pts with NSCLC and
mesothelioma and for those with recurrent disease who
have previously received systemic therapy or RT.

36. • Complications -Reported in 3 to 7% 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.

37. • Stent failure is most often caused by thrombus or
tumor ingrowth.
• However, since most pts 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.
• Need for long-term anticoagulation — Short-term
anticoagulation/antiplatelet therapy is often
recommended.

38. Surgical intervention
• Surgical bypass is now rarely performed because of the
success of endovascular stenting.
• The main proposal for SVC resection is direct
infiltration in thymomas or in N0-N1 non-small cell
lung cancer.
• Armoured PTFE grafts and biologic material are the
preferred choices.
• Morbidity after SVC surgical procedures is high and the
post-operative care must be intensive.
• Long-term patency of a SVC by-pass graft is uncertain
but, usually, the slow onset of the graft thrombosis
favors the development of effective collateral
circulation.

39. • RT provides considerable relief by reducing
tumor burden.
• Response time is 7-15 days but Symptomatic
relief may be apparent as soon as 72 hours.
(Wan J et al., Emerg Med Clin N Am 2009)
• Palliative Schedules are:
– 20 Gy in 5 fractions (4Gy/fraction,1 week)
– 30 Gy in 10 fractions (3Gy/fraction,2week)
Radiation therapy

40. • The fractionation schedule for radiotherapy
– 2.5-4 Gy in 3 fractions,
– followed by daily dose of 1.5-2 Gy,
– Total dose of 35-60 Gy.
• The radiation dose depends on tumor size and
radioresponsiveness.
• The radiation portal should include a 2-cm margin
around the tumor.
• Radiation therapy palliates SVC obstruction in 70% of
patients with lung carcinoma and in more than 95% of
those with lymphoma.

42. Management of Iatrogenic SVCS
• Central venous catheter induced thrombosis
– Thrombolytics (eg, streptokinase, urokinase, or
Recombinant tissue-type plasminogen activator)
– Anticoagulants (eg, heparin or oral
anticoagulants).
• Removal of the catheter, if possible, is another
option, and it should be combined with
anticoagulation to prevent embolization.

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