Overview
Superior Vena Cava Obstruction
Topic Overview
Summary
Superior vena cava obstruction (SVCO) is compression, invasion, or thrombosis of the SVC, impeding venous return from the head, neck, and upper limbs. It is most commonly caused by malignancy (lung cancer, lymphoma, metastases). Classic presentation is facial/neck swelling, dilated neck veins, and upper limb oedema. Stridor or cerebral oedema are life-threatening. Treatment is urgent: dexamethasone, stenting (often first-line), and treatment of underlying cause (chemotherapy, radiotherapy).
Key Facts
- Most common cause: Malignancy (lung cancer 70%, lymphoma, metastases)
- Presentation: Facial swelling, dilated neck veins, arm oedema, dyspnoea
- Life-threatening features: Stridor, cerebral oedema
- Treatment: Dexamethasone + SVC stenting + oncological treatment
- Diagnosis: CT with contrast (CT venogram)
Clinical Pearls
SVCO is usually NOT immediately life-threatening — take time for tissue diagnosis
However, stridor or cerebral oedema = immediate intervention needed
SVC stenting gives rapid symptom relief (hours to days)
Why This Matters Clinically
SVCO is distressing and may be the first presentation of malignancy. Recognising it, excluding life-threatening features, and coordinating oncological management is essential.
Visual Summary
Visual assets to be added:
- SVC anatomy and causes of obstruction
- Clinical photo showing facial swelling and dilated veins
- CT showing SVC compression
- SVCO management algorithm
Epidemiology
Incidence
- 15,000 cases/year in US
- Occurs in 2-4% of lung cancer patients
Demographics
- Median age: 50-70 years
- Male predominance (lung cancer association)
Causes
| Cause | Frequency |
|---|---|
| Lung cancer (especially SCLC) | 50-70% |
| Lymphoma | 10-15% |
| Metastases | 5-10% |
| Thymoma | 5% |
| Benign causes | 10-15% (thrombosis, fibrosing mediastinitis, goitre) |
| Central venous catheter thrombosis | Increasing |
Pathophysiology
Mechanism
- SVC compressed by mediastinal mass or invaded by tumour
- Or thrombosis within SVC (catheter, hypercoagulable)
- Impaired venous return from head, neck, arms
- Venous hypertension → oedema
- Collateral circulation develops (azygos, internal mammary, thoracic veins)
Why Symptoms Vary
- Gradual onset → collaterals develop → less severe symptoms
- Rapid onset → no collaterals → more severe
Life-Threatening Features
- Stridor: Laryngeal oedema
- Cerebral oedema: Headache, confusion, papilloedema
Clinical Presentation
Symptoms
Signs
Pemberton's Sign
Red Flags
| Finding | Significance |
|---|---|
| Stridor | Laryngeal oedema — urgent |
| Confusion, headache, papilloedema | Cerebral oedema — urgent |
| Syncope | Reduced cardiac output |
Facial swelling (worse on bending forward, lying down)
Common presentation.
Neck swelling
Common presentation.
Arm swelling (unilateral or bilateral)
Common presentation.
Dyspnoea
Common presentation.
Cough
Common presentation.
Headache (worse on waking)
Common presentation.
Visual disturbance
Common presentation.
Clinical Examination
General
- Facial plethora
- Periorbital oedema
- Dilated neck veins
Chest
- Chest wall venous distension
- Stridor
- Signs of underlying cause (lung cancer, lymphadenopathy)
Neurological
- Papilloedema (if cerebral oedema)
- Confusion
Investigations
Blood Tests
| Test | Purpose |
|---|---|
| FBC | Baseline |
| U&E, LFTs | Baseline |
| LDH | Elevated in lymphoma |
| Clotting | Pre-biopsy |
| Tumour markers | AFP, β-hCG if germ cell tumour suspected |
Imaging
| Modality | Role |
|---|---|
| CXR | Mediastinal widening, mass |
| CT chest with contrast | Gold standard; shows mass, extent, collaterals |
| CT venogram | Defines SVC obstruction |
Tissue Diagnosis
| Method | Notes |
|---|---|
| Bronchoscopy | If lung mass |
| CT-guided biopsy | Mediastinal mass |
| Lymph node biopsy | If palpable nodes |
| Bone marrow | If lymphoma suspected |
Important: Obtain tissue diagnosis before treatment (unless life-threatening)
Classification & Staging
By Aetiology
- Malignant (most common)
- Benign (thrombosis, fibrosing mediastinitis)
By Severity
- Mild: Facial oedema, dilated veins
- Moderate: Significant dyspnoea, arm swelling
- Severe: Stridor, cerebral oedema
Management
Immediate — If Life-Threatening Features
| Action | Details |
|---|---|
| Sit patient upright | Reduces venous pressure |
| Oxygen | If hypoxic |
| Dexamethasone | 8-16 mg IV (reduces oedema) |
| Urgent SVC stenting | IR procedure for rapid relief |
| Intubation | If airway compromise |
General Management
Dexamethasone:
- 8 mg BD (reduces oedema)
- Limited evidence but commonly used
SVC Stenting:
- First-line for rapid symptom relief
- Interventional radiology
- Relief within hours to days
- High success rate (over 90%)
Oncological Treatment:
- Chemotherapy (SCLC, lymphoma — very chemo-sensitive)
- Radiotherapy (palliative for NSCLC)
- Target underlying malignancy
Anticoagulation:
- If thrombosis identified
- LMWH or DOAC
Sequence
- Stabilise (dexamethasone, stenting if severe)
- Tissue diagnosis (if not immediately life-threatening)
- Definitive oncological treatment
Complications
Of SVCO
- Airway obstruction
- Cerebral oedema
- Death (rare acutely)
Of Treatment
- Stent migration
- Stent thrombosis
- Bleeding from biopsy
- Treatment side effects
Prognosis & Outcomes
Symptom Relief
- Stenting: Over 90% achieve symptom relief
- Radiotherapy: 70-80% response
Prognosis
- Depends on underlying malignancy
- SCLC/lymphoma: May respond well to chemotherapy
- NSCLC: Poorer prognosis
Evidence & Guidelines
Key Guidelines
- NICE Lung Cancer Guidelines
- ESMO Clinical Practice Guidelines
Key Evidence
- SVC stenting provides rapid symptom relief
- Chemotherapy is first-line for chemo-sensitive tumours
Patient & Family Information
What is SVCO?
SVCO is a blockage of a large vein that drains blood from the head, neck, and arms back to the heart. It causes swelling of the face and arms.
Symptoms
- Swelling of the face and neck
- Visible veins on the chest
- Shortness of breath
- Headache
Causes
- Usually caused by a tumour in the chest pressing on the vein
Treatment
- Steroids to reduce swelling
- A stent (small tube) to open the vein
- Treatment for the underlying cause (chemotherapy, radiotherapy)
Resources
References
Key Reviews
- Wilson LD, et al. Clinical practice. Superior vena cava syndrome with malignant causes. N Engl J Med. 2007;356(18):1862-1869. PMID: 17476012
- Drews RE, Rabkin DJ. Malignancy-related superior vena cava syndrome. UpToDate. 2023.
Guidelines
- NICE. Lung Cancer: Diagnosis and Management (NG122). 2019.