Superior Vena Cava Syndrome

This lecture is about the presentation,evaluation, investigation and management of patients presenting with Superior venacava syndrome

1. Superior Vena Cava Syndrome (SCS) Dr. Subhash Thakur Clinical Oncologist, CMC, Bharatpur, Nepal MD (PGIMER, Chandigarh)

2. Contents Introduction Physiology of SVC Obstruction (SVCO) Aetiology Clinical Evaluation Investigations Treatment Stenting in SVCO Radiotherapy Chemotherapy Surgery Thrombolytic and Anticoagulation Summary

3. Introduction A range of signs and symptoms from compression of SVC or associated greater veins (External Compression or Internal Obstruction) Secondary to malignancies: 73-97%

4. Rarely an emergency in absence of tracheal compression However, SVCO has an impact on prognosis Median survival who receive treatment: 46 weeks Median survival without treatment: 6 weeks

5. Physiology of Superior Vena Cava Obstruction Superior Venacava Thin walled, compliant and easily compressible vein 1/3 rd of total venous return to heart Head, neck and upper extremities

6. SVC compression or Obstruction can result in compromise of cardiac output in acute setting, but within few hours, collaterals develop Collateral vessels achieve steady state blood return to the azygous vein or inferior Venacava

7. Severity of Symptoms depend on: Degree of narrowing of SVC and Speed of Onset

8. Acute Setting

9. Aetiology Compression, Invasion or Thrombosis of SVC Result of Inflammatory, Benign or neoplastic processes Lung Cancer is the most frequent malignant cause

10. Principle Causes of SVCO Lung Cancer (52 – 81%) Small cell cancer Non small cell cancer Diffuse large cell cancer Lymphoma (2 -20%) Lymphoblastic Metastatic Disease to Mediastinum Breast Cancer Germ Cell Cancer Gastrointestinal Cancer Others

11. Primary Mediastinal Tumors Thymoma Sarcoma Melanoma Thymic Carcinoma Non-Malignant Causes Infectious diseases: syphilis, Tb, Histoplasmacytosis Central Thrombus and other iatrogenic causes Idiopathic fibrosing mediastinitis Congenital Heart Failure Goiter

12. Clinical Evaluation All patients with suspected SVCO should have thorough clinical history to assess duration and speed of symptom onset History should also involve previous invasive procedures and malignancies Detail examination can rule common differentials like CHF and Cushing's syndrome Careful examination of neurological system: subtle but life threatening due to cerebral Edema

13. Clinical Evaluation Symptoms of SVCO Dyspnea Cough Facial edema Headache Nasal stuffiness Tongue swelling Hoarseness Stridor Signs of SVCO Jugular vein distension Upper extremity swelling Facial and upper body plethora Chemosis Mental status changes Lethargy, Stupor and coma Syncope Cyanosis Papilledema

14. Radiological Evaluation Chest X-ray Often abnormal Can identify superior mediastinal masses or mediastinal widening Hilar masses and pleural effusion

15. Contrast CT or MRI Gold standard Localize the level of SVCO and underlying pathology Tumor mass/size SVC diameter Length of stenosis/obstruction Evidence of SVCO thrombus Formation of collateral vessels

16. Tissue Biopsy Treatment is determined by underlying pathology Sub-acute setting, malignancy is suspected, tissue biopsy should be obtained Can be done via Bronchoscopy Endobronchial ultrasound Mediastinoscopy FNAC or excision biopsy CT guided biopsy

17. Treatment Treatment Stenting in SVCO Radiotherapy Chemotherapy Surgery Thrombolytic and Anticoagulation Head elevation and supplementary Oxygen while obtaining investigations Steroids and diuretics are often used but their evidences are not well studied Anxiolytic and morphine : initial supportive management

18. Stenting in SVCO Safe and effective with rapid resolution of SVCO symptoms Endovascular stenting relieves symptoms in 95% of patients with lung cancer Can be accompanied even if there is complete SVCO or thrombosis Are percutaneously delivered into Venacava under fluoroscopic guidance Available in two fundamental designs: Self expanding or expandable

19. Immediate Endovascular Stenting Life threatening symptoms such as hemodynamic compromise, laryngeal edema or cerebral edema Strongly recommended for patients with limited treatment approaches like mesothelioma Questionable in chemo sensitive tumors like SCLC, Lymphoma and germ cell tumors

20. Complications of stenting 3 – 7% Infection Pulmonary emboli Pericardial tamponade Stent migration Perforation Bleeding Stent failure due to extrinsic tumor compression, infiltration of tumor through the stent or thrombus

21. Radiotherapy An effective treatment modality for certain tumor types as an Initial intervention or Adjuvant treatment after stenting Subjective improvement is seen within 72 hours of initiation of therapy 75% of malignancies associated SCS notice symptomatic improvement within 3 – 5 days, 90% in 1 week Objective response requires 1 – 3 weeks

22. Dose: 30 Gray in 10 # or 50 Gray in 25 # For lymphomas, daily dose of 1.8 to 2 Gy is recommended and for lung cancers 2 to 3 Gy daily dose All locoregional diseases including hilar and supraclavicular region should be treated with sufficient margin

23. Side effects of Radiotherapy Initial worsening of symptoms secondary to edema tumor necrosis with fever myelosuppression alopecia nausea, vomiting stomatitis esophagitis and infection

24. Failure of radiation therapy: Reasons Obstructive Thrombosis Tumor recurrence Radiation fibrosis Failure of development of collaterals secondary to fibrosis The mean post treatment survival is 6 to 7 months

25. Chemotherapy Treatment of Choice for Non Hodgkin lymphoma Germ Cell Tumors SCLC These tumors are exquisitely chemo sensitive Relief of symptoms: 80% of NHL, 77% in SCLC and 40% NSCL patients Symptoms usually improve within 1 – 2 weeks of treatment initiation

26. Targeted Therapy No data available till date

27. Surgery To bypass or resect tumors to decompress the venous system are effective in selected patients However, invasive procedures in this predominantly palliative patients has very limited role In patients with malignant Thymoma and Thymic carcinoma, surgery should be evaluated as part of multimodal treatment strategy

28. Thrombolytics and Anticoagulation Benefit is unclear 30 – 50 % of patients with SVCO have thrombosis at post mortem Experts recommendation: anticoagulation after thrombolysis to Prevent recurrence of thrombus and Reduce the incidence of pulmonary emboli Aspirin is often recommended after stent placement in absence of thrombus

29. Summary SCS is often clinically striking but rarely requires emergency intervention Treatment planning should be multidisciplinary Tissue biopsy is warranted to guide diagnosis and optimize treatment Life threatening symptoms or signs: intravascular stenting provide rapid relief In patients with malignancy, after stenting , radiotherapy/chemotherapy is advised Chemo sensitive malignancies : Chemotherapy should be initiated