AKT · Cardiovascular/Circulation & blood pressurelow yield

Superior vena cava obstruction

Obstruction of the SVC (extrinsic compression/thrombosis) → impaired venous return from the head and arms

Overview

Obstruction of the superior vena cava, usually by extrinsic compression from a mediastinal tumour (lung cancer, lymphoma) or thrombosis around an indwelling line/pacemaker. Venous return from the head, neck and arms is impeded, producing facial/arm swelling, distended veins and breathlessness. It is an oncological emergency when there is airway/cerebral compromise.

Recognise

Facial and upper-limb swelling and plethora, distended neck and chest-wall veins, headache (worse on bending/lying), breathlessness
Pemberton's sign: facial congestion/cyanosis and distress on raising the arms above the head
Underlying cause: lung cancer (esp. small cell), lymphoma, mediastinal mass, or central venous catheter/pacemaker thrombosis

Red flags

Stridor/airway compromise, cerebral oedema (severe headache, confusion) → emergency treatment
New SVCO is often the presenting feature of a malignancy → urgent imaging and tissue diagnosis (unless airway-critical)

Differentials & how to tell them apart

Cardiac failureraised JVP that is pulsatile and falls; bilateral dependent oedema, not facial plethora

Cardiac tamponadehypotension, pulsus paradoxus, effusion on echo

Angioedemaacute allergic facial swelling without distended veins

Investigations

CT chest with contrast (level/cause of obstruction — the key test); tissue diagnosis (biopsy) where possible before treatment, as it guides cancer therapy; CXR (mediastinal mass); assess for thrombus around lines.

Management

Sit up + oxygen + urgent oncology referral; SVC stenting and treat the underlying cause

1Sit the patient up, give oxygen and refer urgently; CT chest to define the cause and level. Obtain a tissue diagnosis where feasible (it guides cancer treatment).Gate: Airway compromise/stridor or cerebral oedema → emergency treatment (stenting, steroids) without waiting; otherwise secure a tissue diagnosis first to direct therapy.
2Endovascular SVC stenting for rapid relief; treat the cause with chemo/radiotherapy (or anticoagulation and line removal for thrombotic SVCO).

Sit up + oxygen; urgent oncology/respiratory referral — supportive; corticosteroids (dexamethasone) often given, especially for steroid-responsive tumours

Endovascular stenting of the SVC — rapid symptom relief, increasingly first-line for malignant SVCO

Treat the cause: chemo/radiotherapy for the tumour; anticoagulation/line removal for thrombotic SVCO — definitive therapy depends on the cause

Key points

Facial/arm swelling + distended neck and chest-wall veins + Pemberton's sign = SVC obstruction, usually from a mediastinal tumour (small-cell lung cancer, lymphoma). Sit up, oxygen, CT chest; stenting gives rapid relief. Airway/cerebral compromise = emergency.

Monitor & prognosis

Symptom relief, airway, response of the underlying tumour, stent patency.

Depends on the underlying cause; stenting palliates well; malignant SVCO often marks advanced disease.

Source: Oncological emergencies guidance