1. Venous thrombosis Dr.mousa Qasim hussein Assistant professor Dep. of internal medicine 10 April 2016

2. Deep vein thrombosis, or deep venous thrombosis, (DVT) is the formation of a blood clot (thrombus) in a deep vein

3. Venous thrombosis May arise either because of : 1-damage to, or pressure on veins (e.g. varicos veins or pelvic tumour), or: veins or pelvic tumour), or: 2-as a result of changes in the plasma or cellular Elements of the blood.

4. Venous thrombosis the most common presentation of venous thromboembolic disease (VTE) is : 1- deep vein thrombosis (DVT) of the leg 2-pulmonary embolism (PE). rarer manifestations such as jugular vein thrombosis upper limb DVT cerebral sinus thrombosis intra-abdominal venous thrombosis (e.g. Budd- Chiari syndrome).

5. DVT has an annual incidence of approximately 1:1000 in Western populations -case mortality is 1-3%. - It is increasingly common with ageing, and many of the deaths are related to coexisting medical conditions.

8. Clinical assessment Lower limb DVT characteristically starts in the distal veins, causing: pain swelling an increase in temperature and dilatation of the superficial veins. Often, however, there are only minimal symptoms and signs.

10. It is typically: unilateral but may be bilateral when clot extends proximally into the inferior vena cava. Bilateral DVT is more commonly seen in patients with underlying malignancy or anomalies of the inferior vena cava.

12. The differential diagnosis of unilateral leg swelling includes: 1- a spontaneous or traumatic calf muscle tear. 2- a ruptured Baker's cyst, both characterised by -sudden onset - localised tenderness. Baker's cysts usually occur in patients with rheumatoid arthritis.

13. 3-Infective cellulitis is usually distinguished by: A- marked skin erythema B- heat which is localised within a well-demarcated area of the leg C- may be associated with an obvious source of entry of infection (e.g. an insect bite or leg ulcer).

14. Risk factors for DVT should be considered, and examination should include assessment for malignancy. Symptoms and signs of PE should be sought, particularly in those with proximal thrombosis; asymptomatic PE is thought to be present in approximately 30% of patients with lower limb DVT.

15. Clinical criteria can be used to rank patients according to their likelihood of DVT using the Wells scoring system

17. of deep vein thrombosis

18. Investigations 1- a low pre-test probability of DVT, D- dimer levels can be measured; if these are normal, further investigation for DVT is unnecessary. D-dimers are a fibrin degradation product, and an elevated level can result from plasmin dissolving a clott 2- moderate or high probability of DVT or with elevated D-dimer levels, objective diagnosis of DVT should be obtained using appropriate imaging.

19. Compression ultrasound is the imaging modality of choice in most centres. It has a sensitivity for proximal DVT (clot involving the popliteal vein or above) of 99.5%. Sensitivity and specificity are lower for diagnosing calf vein thrombosis. Contrast venography is an alternative that is now rarely used.

20. In patients with proven DVT, further imaging to diagnose PE is not required unless massive PE is clinically suspected or there is otherwise unexplained breathlessness.

24. An abdominal CT scan with a clot in the right common iliac vein common iliac vein

25. An ultrasound with a blood clot visible in the left common femoral vein

26. Venograms of DVT

27. Management The management of leg DVT includes elevation and analgesia. Thrombolysis may be considered for limb-threatening DVT, but the mainstay of treatment is anticoagulation with low molecular weight heparin (LMWH) followed by a coumarin anticoagulant, such as warfarin, to achieve a target INR of 2.5 (range 2-3)

28. Treatment of acute VTE with heparin should continue for a minimum of 5 days. If a coumarin is being introduced, the heparin should continue until the INR has been in the target range for 2 days.

29. Patients who have had a DVT and have a strong contraindication to anticoagulation, and those who, despite therapeutic anticoagulation, continue to have new pulmonary emboli, should have an inferior vena cava filter inserted to prevent life- threatening PE.

30. The optimal duration of anticoagulation is between 6 weeks and 6 months. Patients who have thrombosis in the presence of a temporary risk factor which is then removed can usually be treated for shorter periods (e.g. 3 months) than those who sustain unprovoked thrombosis.

31. In patients with active cancer and VTE, there is evidence that LMWH should be continued for 6 months rather than being replaced by a coumarin. Evidence indicates that periods of anticoagulation of more than 6 months do not alter the rate of recurrence following discontinuation of therapy.

32. Recurrence of DVT is about 2-3% per annum in patients who have a medical temporary risk factor at presentation and about 10% per annum in those with apparently unprovoked DVT. This plateaus at around 30-40% recurrence at 5 years

33. Post-thrombotic syndrome is due to damage of venous valves by the thrombus. It results in persistent leg swelling, heaviness and discoloration. The most severe complication of this syndrome is ulceration around the medial malleolus.

34. Treatment options for PTS include proper leg elevation, compression therapy with elastic stockings, or electrostimulation devices, herbal remedies (such as horse chestnut,, pentoxifylline), and wound care for leg ulcers. PTS in the legs is often exacerbated by blockage of draining veins in the pelvis or abdomen (iliac veins and IVC), and opening of these veins (by application of angioplasty and vascular stents by an experienced physician) can provide significant relief of swelling and healing of skin ulcers. Compression bandages are useful to treat edemas.

35. Prophylaxis of venous thrombosis All patients admitted to hospital should be assessed for their risk of developing VTE. Both medical and surgical patients are at increased risk.

36. Early mobilisation of all patients is important to prevent DVT. Patients at medium or high risk require additional antithrombotic measures; these may be pharmacological or mechanical

37. There is increasing evidence in high-risk groups, such as patients who have had major lower limb orthopaedic surgery, for protracted thromboprophylaxis extending out to 30 days after the procedure. Particular care should be taken with the use of pharmacological prophylaxis in patients with a high risk of bleeding or with specific risks of haemorrhage related to the site of surgery or the use of spinal or epidural anaesthesia.

39. Methods of VTE prophylaxis Mechanical Intermittent pneumatic compression Mechanical foot pumps Graduated compression stockings The ACCP suggested graduated compression stockings for at-risk travelers and some hospital patients.

40. IPC pumps and garments provide a safe and effective method of preventing Venous Thromboembolism (VTE) by replicating what the body does naturally.

42. Pharmacological Low molecular weight heparins Unfractionated heparin Fondaparinux Dabigatran Rivaroxaban Warfarin Aspirin