Superior Vena Cava syndrome occurs when blood flow is obstructed in the superior vena cava, typically due to external compression or invasion by a lung or mediastinal malignancy (1). It presents with swelling of the face, neck, and arms due to elevated venous pressure above the obstruction (2). Diagnosis involves imaging like CT scans to locate the obstruction and identify its cause, while treatment aims to both relieve venous obstruction and address the underlying condition (3). Options for relieving obstruction include endovascular stenting, angioplasty, or surgical bypass/replacement of the superior vena cava.

1. Superior Vena Cava syndrome
Dr. K. Srikanth
DNB (Cardiothoracic Surgery) Resident – 3rd year
Narayana Hrudayalaya, Bangalore
01.11.2019

2. Scope of my talk
• Anatomy of SVC and its tributaries
• Pathophysiology
• Etiology
• Clinical presentation
• Diagnosis
• Management – Interventional/ Surgical

3. Relevance to our speciality
• As a cardiothoracic surgeon, you may encounter this clinical entity
when dealing with late stage lung /mediastinal malignancies,
incidence being 5-10% in right sided intra-throracic malignancies
• Should know the various available options in our armamentarium to
handle this problem including endovascular interventions
• Familiarise yourselves with the surgical techniques to treat SVC
obstruction

4. Anatomy of SVC
• SVC carries venous return to the heart from the tissues above the
diaphragm.
• Formed by the junction of the right and left brachiocephalic veins
behind the lower border of the first right costal cartilage near the
sternum
• Thin-walled, low pressure system approximately 7 cm in length, 20-
22mm in diameter

5. • Descends vertically and ends in the upper right atrium behind the
third right costal cartilage
• Its inferior half is within the fibrous pericardium, which it pierces level
with the second costal cartilage
• The superior vena cava has no valves
• Azygous vein and a few small pericardial veins are the direct
tributaries to SVC

7. Relations of SVC
• Anterior - Anterior margins of the right
lung and pleura above and the pericardium
below
• Posteromedial - Trachea and right vagus
nerve
• Posterolateral - Right lung and pleura
• Posterior - Right pulmonary hilum
• Right lateral - Right phrenic nerve and
pleura
• Left lateral - Brachiocephalic artery and
ascending aorta

8. SVC syndrome – What is it?
Constellation of signs and symptoms caused by
obstruction of blood flow in the superior vena cava
due to partial or complete obstruction secondary to
external compression, invasion, constriction or
thrombosis of the SVC
• William Hunter first described the syndrome in 1757 in a patient with
syphilitic aortic aneurysm

9. Pathophysiology of SVCS
• Obstruction of SVC blood flow from the brachiocephalic veins to right
atrium
• Vascular resistances rise and the venous return decreases. The resultant
upstream cervical venous pressure may be increased from 2 to 8 mm Hg to
between 20 to 30 mm Hg, which causes clinical manifestations, including
facial and arm edema.
• Bilateral occlusion of the brachiocephalic veins can also produce similar
symptoms.
• SVC pressure increases consistently
• Over a period of time, collateral circulation opens up to bypass the
obstruction and restore the venous return to the RA

10. • The timing of 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 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. Collateral systems in SVC obstruction
• 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.

12. Azygous venous
system

13. Three levels of SVC obstruction
• Supra-azygous SVC obstruction
• SVC obstruction with azygous involvement
• Infra-azygous SVC obstruction

14. Supra-azygous SVC
obstruction

15. SVC obstruction with
azygous involvement

16. Infra-azygous SVC
obstruction

17. Etiology
• Previously infectious diseases such as Tuberculosis, Syphilis,
Histoplasmosis and Actinomycosis used to be the common cause of
SVCS
• In the present day, because of antimicrobial therapy and improved
social conditions those have become rarer causes
• Malignancy tops the list with about 60% of the cases of SVCS being
attributed to it, followed by indwelling catheters like dialysis
catheters/ chemoports (Hickman)

19. Less common causes of SVCS
• Post-cardiac surgery (Heart transplant, Baffles)
• Retrosternal goitre
• Sarcoidosis
• Radiation-induced

20. Clinical presentation
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)

21. Symptoms
• Swelling of the upper chest, arms, neck and face (periorbital initially)
usually more on the right side, because of the better possibility of
collateral circulation in the left brachiocephalic vein
• Cough
• Epistaxis
• Hemoptysis
• Dysphagia
• Dysphonia
• Hoarseness (caused by vocal cord congestion)

23. Yu’s clinical grading of SVC obstruction
• 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

24. Signs of SVCS
Video

25. Diagnosis
• SVCS is a clinical diagnosis because of the obvious features but
necessitates additional imaging studies to localize the obstruction
and to identify the cause of obstruction
• Imaging includes Chest X-ray, CT /MRI scan and PET scan if required
• Additional investigations like sputum cytology/ biopsy/
bronchoscopy/ mediastinoscopy as and when required

26. Chest X-Ray
• A right hilar or upper lobe lung lesion
• Mediastinal lymphadenopathy
• Mediastinal or hilar calcification suggests the
diagnosis of fibrosing granulomatous
mediastinitis
• A normal x-ray in the absence of previous
surgical procedures or instrumentation is
almost pathognomonic of superior vena caval
obstruction secondary to chronic fibrosing
mediastinitis

27. CT chest with contrast
• Computed tomography provides more definitive information as to the
extent and mechanism of caval obstruction, whether by compression,
direct tumour invasion or intraluminal thrombosis and also the extent of
collateralisation
• It also serves to suggest further diagnostic testing, especially fine-needle
aspiration or core biopsies when these procedures are indicated. CT is less
invasive than bronchoscopy or mediastinoscopy for the initial evaluation
Two criteria that must be met to confirm the diagnosis of superior vena caval
obstruction on contrast CT scanning
• Non-opacification with IV contrast of the superior vena cava inferior to the
site of obstruction
• Opacification with contrast of collateral venous structures

30. Other ancillary investigations
• A sputum cytology is the easiest and least invasive way to establish a malignant
diagnosis
• Fiberoptic bronchoscopy with transbronchial biopsy has been an effective tool in
establishing a malignant diagnosis in superior vena cava syndrome.
• In the presence of an endobronchial mass, a direct biopsy and assessment of the extent
of the tumor are possible
• In the absence of an identifiable endobronchial mass, selective subsegmental bronchial
washings and brush collections for cytology are often diagnostic and localize the
involved bronchopulmonary segment.
• A lymph node aspiration or biopsy in the presence of cervical adenopathy or
thoracentesis for a pleural effusion may provide either a cytologic or histopathologic
diagnosis. A positive diagnosis of malignancy with either procedure also establishes
surgical non-resectability

31. • Mediastinoscopy, mediastinotomy and video-assisted thoracoscopy with
biopsies are excellent approaches for diagnosis and staging in most
patients with lung cancer
• However, these procedures may be hazardous and must be utilized with
caution to avoid bleeding complications from the dilated, thin-walled, high-
pressure cervical, mediastinal, and chest wall venous collaterals that
accompany this syndrome.
• Intravenous biopsy and percutaneous venous atherectomy have also been
usedto establish a histologic diagnosis. Alterative methods to safely obtain
a tissue diagnosis include EBUS (endobronchial ultrasound) and
navigational bronchoscopy biopsy.
• Venography and venous nuclear scintigraphy are pretty much historical

32. Stanford classification of SVCS
• Radiologic (angiographic) stages of vena cava obstruction was developed to assist
in identifying patients at risk of substantial airway or cerebral compromise and
therefore warranting rapid intervention
• Stanford type I: mild SVC obstruction, with vessel obstruction of less than 90%
• Stanford type II: high-grade SVC stenosis (grade of stenosis 90 –100%)
• Stanford type III: complete SVC obstruction and prominent flow through collateral
veins, but without involvement of the mammary and epigastric veins
• Stanford type IV: complete SVC obstruction and prominent flow through collateral
veins and the mammary and epigastric veins

34. Management of SVCS
The goals of managing SVC syndrome are two
• Relive symptoms due to venous obstruction
• Identify and treat the causative factor

35. Emergency treatment
Usually SVC syndrome is a gradually progressive condition, if acute
obstruction happens in case of thrombosis or trauma, emergency
treatment is indicated in patients with
• Central airway compromise
• Severe laryngeal edema
• Coma secondary to cerebral edema

36. Supportive Care
• Elevation of head end of bed to decrease the hydrostatic pressure and
thereby the facial and cervical edema
• Supplemental oxygen therapy
• Diuretics and corticosteroids - reduce cerebral edema (and laryngeal
edema to some extent)
• Glucocorticoids reduce the tumor burden in Lymphoma and
Thymoma - likely to reduce the obstruction.

37. Interventions to relieve the SVC obstruction
• Intravenous thrombolysis
• SVC balloon angioplasty
• Endovascular stenting

38. Balloon SVC angioplasty
• Video
• Similar to coronary angioplasty
• Useful to immediately restore the forward flow due to obstruction,
especially intrinsic than extrinsic

39. Endovascular stents
Indications:
• It is a useful procedure for patients with severe symptoms (eg,
stridor) who require urgent intervention
• Can be placed before a tissue diagnosis is available
• For rapid symptom palliation in patients with NSCLC and
mesothelioma and for those with recurrent disease who have
previously received systemic therapy or RT

41. • Stent failure is most often caused by thrombus or tumor ingrowth
• However, since most patients with malignancy related SVC syndrome
have a short life expectancy, the stent usually remains patent until
death
• If re-occlusion does occur, it can be treated with a balloon dilatation,
second stent or thrombolytic therapy, with good secondary patency
rates
• Need for long-term anticoagulation/antiplatelet therapy is often
recommended.

42. Surgical options
• Expanded saphenous spiral vein bypass
• Jugulo-atrial bypass with RSVG
• Internal jugular to femoral vein bypass with in-situ saphenous vein
• SVC Replacement with artificial conduits

43. Indications of surgical treatment
Due to the advent of interventional methods, the role of surgery is
predominantly restricted to cases with
• Failure of conservative measures/ interventional techniques
• Surgically correctable cause of SVC obstruction like a resectable
malignancy/ benign lesions

44. Expanded saphenous spiral vein bypass

45. Jugulo-atrial conduit

46. Internal jugular to femoral vein bypass with in-situ
saphenous vein

47. SVC Replacement
• The obstructed portion of the SVC is resected partially or in-toto and
reconstructed/ replaced with an artificial conduit like PTFE or bovine
pericardium
• Long-term patency rates of such conduits is promising
• Video

48. Take home messages
• SVC obstruction – not a rare entity
• Should recognise the clinical signs of SVC obstruction
• Collaterals – natural bypass
• Treatment – Relief of obstruction + Treatment of causative factor
• Endovascular intervention Vs Surgical therapy – When to do what?
• To keep in mind the various options for bypass/ replacement

49. Thank You!