A venous thrombus is a blood clot that forms in the veins. It can lead to a pulmonary embolism if parts of the clot break off and travel to the lungs. Venous thrombosis is caused by damage to the vessel wall, slowed blood flow, and increased coagulability. Risk factors include injuries to the lower limbs, pregnancy, oral contraceptives, and cancer. Diagnosis involves testing for d-dimer and ultrasound imaging of the veins. Treatment consists of blood thinners like heparin and warfarin to prevent clot growth as well as thrombolysis to break up existing clots.

2. INTRODUCTION
• A venous thrombus is the formation of a semi
solid coagulum within flowing blood in the
venous system.
• Venous thrombosis of deep veins of the leg is
complicated by immediate risk of pulmonary
embolus and sudden death.
• Risk of developing a post-thrombotic limb and
venous ulceration.

3. AETIOLOGY
• Changes in the vessel wall(endothelial
damage)
• Stasis ,diminished blood flow
• Coagulability of blood (thrombophilia)
Predisposing factors:
Injury ,esp fractures of the lower limb and pelvis
pregnancy and the oral contraceptive pills.

4. PATHOLOGY
• A thrombus often develop in he soleal veins
of the calf.
• Fibrin and red cells form a mesh until the
lumen of the vein wall occludes.
• Thrombus extend as a propagated loose red
clot.
• Extend up to the large venous branch ,break
off and embolise to the lung.

5. • Embolus arising from the lower leg veins
becomes detached passes through the large
veins of the limb and venacava.
• Lodges in the pulmonary arteries
• Occlude the pefusion to all or part of one or
both lungs.
• Sudden collapse and death.

7. DIAGNOSIS
• The most common presentation in DVT is pain
and swelling esp in the calf.
• Many patients have no symptoms of
thrombosis and present with pulmonary
embolism.
• Sometimes leg appears cellulitic.
• Presenting with venous gangrene have
underlying neoplasm.

8. • Mild pitting edemaof the ankle ,dialated
veins,stiff calf and tenderness over the course
of the deep veins.
• Low grade pyrexia in patients with pulmonary
embolism.
• Signs-cyanosis, dyspnoea, raised neck veins,
split second heart sound, pleural rub if there is
right heart strain.

9. INVESTIGATION
• Patients with idiopathic thrombosis ususally
have a D-dimer measurement.
• If d-dimer is raised ,a Duplex ultrasound
examination of the deep veins should be
performed.
• Ascending venography
• CTscan

10. DIFFERENTIAL DIAGNOSIS
• Ruptured baker’s cyst
• calf muscle haematoma
• Ruptured plantaris muscle
• Thrombosed popliteal aneurysm
• Arterial ischaemia

11. PROPHYLAXIS
Prophylactical methods include:
• Mechanical
• Pharmacological
Mechanical :graduated elastic compression
stocking,external pneumatic compression.
These reduces the incidence of thrombosis.
Pharmacological:low molecular weight heparin
given sc .

12. TREATMENT
• Patients confirmed to have DVT on duplex
imaging should be started on sc low
molecular weight heparin&rapidly
anticagulated with warfarin.
 Warfarin started at a dose of 10mgon day 1
 10mg on day 2
 5mg on day 3.
• Prothrombin time is taken on day 3.

13. • Thrombolysis :Tissue plasminogen activator
in most patients is administered directly into
the thrombus ,via the popliteal vein or by
direct puncture in the groin.
• Thrombi can be compressed by stent
grafting,this technique is very good in
patients with ‘iliac vein compression
syndrome’.