Superior vena cava syndrome
Superior vena cava (SVC) syndrome is obstruction of blood flow through the SVC, most often from extrinsic compression by a mediastinal malignancy (lung cancer causes about 75% of cases) or, less commonly, catheter-related thrombosis. Contrast-enhanced chest CT establishes the diagnosis. Unless stridor, cerebral edema, or hemodynamic compromise demand emergency endovascular stenting, tissue biopsy precedes treatment, which targets the underlying malignancy with chemotherapy, radiation, or surgery.
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What this article covers
- Overview
Superior vena cava (SVC) syndrome is the set of findings that follows obstruction of blood flow through the SVC, the thin-walled vessel returning blood from the head, neck, and arms to the right atrium.
- Epidemiology
SVC syndrome develops in patients with intrathoracic malignancy, typically an older adult with a heavy smoking history presenting with subacute dyspnea, facial swelling, and cough evolving over days to weeks.
- Risk factors
Tobacco smoking: the dominant risk factor, driving the lung cancers that cause most cases.
- Pathophysiology
The SVC is a low-pressure, thin-walled vessel confined in a rigid mediastinal space bounded by the trachea, right mainstem bronchus, aorta, pulmonary artery, and lymph node stations, which makes it vulnerable to compression.
- Clinical features
Facial and upper-body edema: worse on waking and after lying flat or bending forward, improving somewhat when upright.
- Differential diagnosis
Upper extremity deep vein thrombosis: unilateral arm swelling, redness, and pain, often catheter-related, but without facial swelling or jugular venous distention.
- Diagnosis
First, assess airway and hemodynamic status at the bedside, then obtain a chest radiograph: vital signs, oxygen saturation, and exam for stridor, altered mental status, or hypotension identify who…
- Management
First, identify patients needing emergency intervention: stridor, significant laryngeal or cerebral edema, or hemodynamic compromise warrant endovascular SVC stenting without waiting for a tissue…
- Complications
Cerebral edema and raised intracranial pressure: from venous congestion, causing headache and confusion, and rarely rupture of intracranial collateral vessels; drives the emergency stenting decision in rapid-onset, severe cases.
- Prognosis
SVC syndrome itself is rarely fatal, and deaths directly attributable to it are uncommon; prognosis is governed by the stage and chemosensitivity of the underlying malignancy rather than by the syndrome itself.
- Prevention
Smoking cessation: the single most effective measure against the lung cancer that causes most cases.
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