Paget Schroetter Syndrome

Effort thrombosis: thrombosis of the axillary or subclavian vein from repeated trauma where the vein passes through the thoracic outlet, usually in young, healthy, active people. It is the primary form of upper extremity deep vein thrombosis and accounts for about 1 to 4% of all deep vein thrombosis.

• Incidence is about 1 to 2 per 100,000 per year, with male predominance (about 2:1), mean age about 30 years, and about two thirds affecting the dominant arm. Typical patients are athletes and workers with repetitive overhead arm use: swimmers, baseball players, rowers, weightlifters, tennis players, wrestlers, painters, and musicians.
• Mechanism: the costoclavicular space is narrowed by the first rib, clavicle, subclavius muscle and tendon, costoclavicular ligament, and anterior scalene muscle (hypertrophy with training, a cervical rib, a fibrous band, or a healed clavicle fracture). Repeated compression causes venous endothelial injury, perivenous fibrosis, stenosis and thrombosis. An underlying thrombophilia contributes in a minority (about 10 to 20%).
• Without definitive correction, chronic arm symptoms and rethrombosis are common; with early thrombolysis and decompression, outcome is excellent (about 90% or more return to full activity).

• Sudden arm swelling, heaviness, aching, discolouration (blue, dusky), venous distension and dilated collateral veins around the shoulder, chest and upper arm after strenuous or prolonged arm activity. Symptoms often develop over hours to days; symptom severity depends on collaterals.
• Signs: swollen, tense arm, cyanosis, prominent veins on the anterior chest wall and shoulder, warmth, tenderness along the axillary vein, and normal arterial pulses (arterial or neurogenic thoracic outlet syndrome may coexist).
• Differential diagnosis: secondary upper extremity thrombosis (catheter, cancer), cellulitis, lymphoedema, muscle strain or haematoma, arterial thoracic outlet syndrome, neurogenic thoracic outlet syndrome, superior vena cava syndrome, axillary vein compression by tumour or lymph nodes, and Pancoast tumour.
• Complications: pulmonary embolism (about 5 to 10%), post-thrombotic syndrome with chronic arm pain and swelling (about 10 to 30% without treatment), recurrent thrombosis, loss of athletic function, and venous gangrene (very rare).

• Compression ultrasonography with colour Doppler (non-compressible axillary or subclavian vein, absent respiratory variation, absent flow); central veins are poorly seen so a negative scan with a typical history needs further imaging.
• Contrast venography (also therapeutic): thrombus and the characteristic extrinsic compression of the subclavian vein at the costoclavicular junction, collaterals, and dynamic compression with the arm abducted. CT or MR venography when venography is not planned, to define the first rib, cervical rib, and the thoracic outlet anatomy.
• Blood tests: full blood count, creatinine, coagulation, and thrombophilia screen (lupus anticoagulant, anticardiolipin and beta-2 glycoprotein I antibodies, factor V Leiden, prothrombin gene variant, protein C and S, antithrombin) given the young age; chest X-ray (cervical rib, mass); pregnancy test.

• Treatment is staged: early restoration of flow, anticoagulation, then correction of the compression.
• Immediate: unfractionated heparin 80 units/kg IV bolus then 18 units/kg/h (aPTT 1.5 to 2.5 times control), or enoxaparin 1 mg/kg SC twice daily; analgesia with paracetamol 1 g four times daily; arm elevation.
• Thrombolysis (best within 14 days of symptoms, up to about 4 weeks selected), restores patency in about 90% when done early:
  • Catheter directed alteplase 0.5 to 1 mg/h (maximum total about 20 to 40 mg) through a multi-side-hole catheter, with heparin 500 to 1000 units/h through the sheath, checking fibrinogen every 4 to 6 hours (stop at less than 1 g/L) and repeat venography at 12 to 24 hours; pharmacomechanical or aspiration thrombectomy as an alternative. Typical infusion lasts 12 to 48 hours.
  • Contraindications: active bleeding, stroke or intracranial surgery within 3 months, major surgery or trauma within 3 weeks, uncontrolled hypertension (greater than 180/110 mmHg), brain metastases.
  • Do not place a stent before decompression, because the compressed stent fractures and thromboses.
• Anticoagulation after thrombolysis: enoxaparin 1 mg/kg SC twice daily, then rivaroxaban 20 mg once daily or apixaban 5 mg twice daily (or warfarin to INR 2.0 to 3.0) until surgery and for 1 to 3 months afterwards. Avoid direct oral anticoagulants in antiphospholipid syndrome.
• Surgical decompression of the thoracic outlet:
  • First rib resection (transaxillary, supraclavicular or paraclavicular approach), with scalenectomy, removal of a cervical rib and fibrous bands, and venolysis, performed 1 to 3 months after thrombolysis (some centres operate within 2 to 5 days of thrombolysis during the same admission, with similar results and less recurrence).
  • Completion venography after decompression: balloon angioplasty of residual stenosis (greater than 50%) is done after decompression, with stent placement only for recurrent or recoil stenosis (evidence is limited).
  • Venous reconstruction (jugular vein turndown, patch angioplasty or bypass) for persistent occlusion with disabling symptoms.
  • Anticoagulate for 1 to 3 months after surgery and stop if the vein is patent on repeat venography or duplex ultrasonography; continue for 3 to 6 months or longer if residual stenosis, thrombophilia or recurrence.
• Without decompression, recurrence and chronic disability are common, so conservative treatment (anticoagulation alone) is reserved for older, sedentary, high risk or unwilling patients (evidence is limited).
• Rehabilitation: early supervised arm movement after decompression, graded return to overhead sport at 6 to 12 weeks, and avoidance of provocative positions until cleared.
• Symptom control: elevation, compression sleeve for residual swelling, and analgesia with paracetamol 1 g four times daily (avoid NSAIDs while anticoagulated).
• Special groups:
  • Pregnancy: enoxaparin 1 mg/kg SC twice daily through pregnancy and for at least 6 weeks postpartum; avoid warfarin and direct oral anticoagulants; delay decompression until after delivery unless limb threatening.
  • Children and adolescents: rare; anticoagulate with weight based enoxaparin 1 mg/kg twice daily.
  • Thrombophilia: extend anticoagulation after surgery as advised by haematology; antiphospholipid syndrome needs warfarin.
  • Renal impairment: unfractionated heparin when creatinine clearance is less than 30 mL/min; avoid contrast load when possible.
• Red flags: chest pain or breathlessness, a cold or pulseless arm (arterial involvement), severe pain with cyanosis, bleeding on thrombolysis, falling platelets on heparin.
• Follow up: review at 1 week and 1 month after intervention; duplex ultrasonography at 1, 3 and 6 months and then yearly if symptoms recur; return to sport after radiological patency and symptom resolution; counsel on recurrence symptoms.