Superficial Venous Thrombosis

Thrombosis with inflammation in a superficial vein, most often the great saphenous vein, the small saphenous vein or their tributaries in the leg, and less often an arm vein after cannulation. Incidence is about 1 per 1000 adults per year, probably an underestimate. It is commoner in women and with age.

• Risk factors: varicose veins (present in about 60 to 80%), previous venous thromboembolism, obesity, pregnancy and the puerperium, oestrogen therapy, active cancer, inherited or acquired thrombophilia, prolonged immobility, recent surgery or sclerotherapy, infusion of irritant drugs through a cannula, and autoimmune disease (Behçet disease, thromboangiitis obliterans).
• Mechanism: stasis, endothelial injury and a hypercoagulable state produce thrombus and perivenous inflammation. Thrombus can extend into the deep system through the saphenofemoral junction, the saphenopopliteal junction or perforating veins.
• It is not benign: about 25% of patients with leg disease have a deep vein thrombosis at presentation, and without anticoagulation about 5 to 10% develop symptomatic deep vein thrombosis, pulmonary embolism or extension within 3 months. A thrombus 5 cm or longer carries the highest risk. Pain settles in 1 to 3 weeks, but a palpable cord and pigmentation can persist for months.

• Pain, redness, warmth and tenderness along a hard, cord like vein, with induration of the overlying skin, swelling, low grade fever and later pigmentation. In the leg the cord follows the medial thigh, the calf or a varicose segment; in the arm it follows the cannulated vein.
• Purulence, high fever, rigors or bacteraemia indicate suppurative thrombophlebitis, usually cannula related.
• Recurrent or migratory thrombosis (appearing at new sites) suggests cancer (Trousseau syndrome), Behçet disease, thromboangiitis obliterans, antiphospholipid syndrome or a myeloproliferative neoplasm.
• Differential diagnosis: cellulitis, lymphangitis, deep vein thrombosis, erythema nodosum, panniculitis, ruptured Baker cyst, localised vasculitis (polyarteritis nodosa), insect bite, and Mondor disease (thrombosis of a chest wall vein).
• Complications: extension to the deep veins, deep vein thrombosis and pulmonary embolism, suppurative thrombophlebitis with sepsis, recurrence, persistent pain and pigmentation, and bleeding on anticoagulation.

• Clinical, confirmed by duplex ultrasonography of both legs: shows a non-compressible superficial vein with thrombus, measures its length and its distance from the saphenofemoral or saphenopopliteal junction, and excludes concurrent deep vein thrombosis.
• Blood tests: full blood count with platelets, creatinine (to choose the anticoagulant dose), CRP. D-dimer has no role.
• Thrombophilia tests only when thrombosis is unprovoked, recurrent, migratory, of young onset, or there is a family history: lupus anticoagulant, anticardiolipin and beta-2 glycoprotein I antibodies (repeat at 12 weeks), factor V Leiden, prothrombin gene variant, JAK2 V617F. Look for cancer by history, examination, chest X-ray and age appropriate tests when the cause is unexplained.
• Blood cultures and a swab of any discharge when infection is suspected.

• Choose treatment by thrombus length and distance from the deep system.
• Symptomatic care for all patients:
  • Normal walking (bed rest is not needed) and leg elevation when seated.
  • Class 2 compression stockings (20 to 30 mmHg) or bandage for 2 to 4 weeks as pain allows.
  • Topical diclofenac 1% gel 2 to 4 g four times daily over the cord for 7 to 14 days, or a heparinoid gel.
  • Oral NSAID for 7 to 14 days: ibuprofen 400 mg three times daily with food, or naproxen 500 mg twice daily, with omeprazole 20 mg daily for patients at gastric risk. Avoid with renal impairment, peptic ulcer, heart failure, concurrent anticoagulation and after 20 weeks of pregnancy.
  • Paracetamol 1 g four times daily.
• Thrombus less than 5 cm long and more than 3 cm from the junction: symptomatic care and repeat duplex ultrasonography at 7 to 10 days (extension occurs in about 10%). Add enoxaparin 40 mg SC once daily for 10 to 14 days when risk factors exist (previous venous thromboembolism, cancer, recent surgery, immobility, pregnancy) or the thrombus lies in the great saphenous vein.
• Thrombus 5 cm or longer and more than 3 cm from the junction (prophylactic dose anticoagulation for 45 days):
  • Fondaparinux 2.5 mg SC once daily (1.5 mg daily when creatinine clearance is 20 to 50 mL/min; contraindicated when less than 20 mL/min; evidence is limited under 50 kg), or
  • Enoxaparin 40 mg SC once daily (20 mg daily when creatinine clearance is less than 30 mL/min), or
  • Rivaroxaban 10 mg orally once daily (avoid when creatinine clearance is less than 15 mL/min).
  • Repeat duplex ultrasonography at the end of treatment, and sooner if symptoms worsen.
• Thrombus within 3 cm of the saphenofemoral or saphenopopliteal junction, or extending into the deep system: give therapeutic anticoagulation for at least 3 months:
  • Rivaroxaban 15 mg twice daily with food for 21 days, then 20 mg once daily; or apixaban 10 mg twice daily for 7 days, then 5 mg twice daily; or
  • Enoxaparin 1 mg/kg SC twice daily (once daily if creatinine clearance is less than 30 mL/min), overlapped with warfarin for at least 5 days until INR is 2.0 to 3.0 for 24 hours.
  • Ligation of the saphenofemoral junction is an alternative only when anticoagulation is contraindicated.
• Suppurative thrombophlebitis:
  • Remove the cannula and send the tip and blood for culture.
  • Flucloxacillin 2 g IV every 6 hours, adding vancomycin 15 to 20 mg/kg IV every 8 to 12 hours (trough 15 to 20 mg/L) when methicillin resistant Staphylococcus aureus is likely. Adjust to culture. Give for 2 to 4 weeks, and for 4 to 6 weeks if bacteraemia persists or there is metastatic infection.
  • Excise the infected vein segment if infection persists, and perform echocardiography when bacteraemia persists.
• Arm vein thrombosis after a cannula: remove the cannula, apply warm compresses and a topical NSAID; anticoagulate only when thrombus is 5 cm or longer or extends toward the deep veins.
• Treat the cause: cancer therapy, stop oestrogen, prednisolone 0.5 to 1 mg/kg/day with azathioprine 2.5 mg/kg/day for Behçet disease, complete tobacco cessation in thromboangiitis obliterans, and warfarin to INR 2.0 to 3.0 for antiphospholipid syndrome with recurrent thrombosis.
• Varicose veins: once the acute episode settles (usually 6 to 12 weeks), refer for endovenous thermal ablation or foam sclerotherapy of incompetent veins to reduce recurrence.
• Special groups:
  • Pregnancy and puerperium: enoxaparin 40 mg SC daily (20 mg under 50 kg, 60 mg for 91 to 130 kg, 80 mg for 131 to 170 kg) for at least 6 weeks; avoid warfarin and direct oral anticoagulants; avoid NSAIDs after 20 weeks.
  • Cancer: enoxaparin 40 mg SC daily for at least 45 days, with therapeutic dosing if thrombus extends toward the deep system.
  • Elderly and renal impairment: reduce enoxaparin and fondaparinux by creatinine clearance; avoid NSAIDs.
  • Heparin induced thrombocytopenia: stop heparin; fondaparinux 2.5 mg SC daily is acceptable.
• Red flags: swelling of the whole leg, chest pain or breathlessness, fever with pus or rigors, thrombus approaching the junction, a rapidly extending cord.
• Follow up: review at 1 week and 6 weeks, duplex ultrasonography at 7 to 10 days and at the end of treatment, treatment of varicose veins, and repeat cancer assessment for recurrent or unexplained disease.