By: Dr. Nalaka Gunawansa DVT Management By: Dr. Nalaka Gunawansa

What is DVT? Deep vein thrombosis is the formation of a blood clot in one of the deep veins of the body, usually in the leg.

Virchow triad More than 100 years ago, Virchow described a triad of factors of venous stasis, endothelial damage, and hypercoagulable state

Diagnostic investigations and diagnosis Treatments: pharmacological interventions thrombolytic therapy mechanical interventions Patient information verbal and written self-management Investigations for cancer Thrombophilia testing

Management Using the pretest probability score calculated from the Wells Clinical Prediction rule, patients are stratified into 3 risk groups—high, moderate, or low. The results from duplex ultrasound are incorporated as follows: If the patient is high or moderate risk and the duplex ultrasound study is positive, treat for DVT.

Anticoagulation Thrombolytic therapy for DVT Surgery for DVT Filters for DVT Compression stockings

The primary objectives of the treatment of DVT are to prevent pulmonary embolism, reduce morbidity, and prevent or minimize the risk of developing the postphlebitic syndrome.

1.Anticoagulation Heparin prevents extension of the thrombus Heparin's anticoagulant effect is related directly to its activation of antithrombin III. Antithrombin III, the body's primary anticoagulant, inactivates thrombin and inhibits the activity of activated factor X in the coagulation process.

The optimal regimen for the treatment of DVT is anticoagulation with heparin or an LMWH followed by full anticoagulation with oral warfarin for 3-6 months Warfarin therapy is overlapped with heparin for 4-5 days until the INR is therapeutically elevated to between 2-3. 3 LMWH preparations, Enoxaparin, Dalteparin, and Ardeparin

Advantages of Low-Molecular-Weight Heparin Over Standard Unfractionated Heparin Superior bioavailability Superior or equivalent safety and efficacy Subcutaneous once- or twice-daily dosing No laboratory monitoring* Less phlebotomy (no monitoring/no intravenous line) Less thrombocytopenia Earlier/facilitated

Warfarin Interferes with hepatic synthesis of vitamin K-dependent coagulation factors Dose must be individualized and adjusted to maintain INR between 2-3 2-10 mg/d PO caution in active tuberculosis or diabetes; patients with protein C or S deficiency are at risk of developing skin necrosis

In patients with a high clinical suspicion of acute VTE, we suggest treatment with parenteral anticoagulants compared with no treatment while awaiting the results of diagnostic tests In patients with an intermediate clinical suspicion of acute VTE, we suggest treatment with parenteral anticoagulants compared with no treatment if the results of diagnostic tests are expected to be delayed for more than 4 h (Grade 2C). In patients with a low clinical suspicion of acute VTE, we suggest not treating with parenteral anticoagulants while awaiting the results of diagnostic tests, provided test results are expected within 24 h (Grade 2C) .

2.Thrombolytic therapy for DVT Advantages include prompt resolution of symptoms, prevention of pulmonary embolism, restoration of normal venous circulation, preservation of venous valvular function, and prevention of postphlebitic syndrome.

Disadvantage include, clot propagation, rethrombosis, or subsequent embolization. Heparin therapy and oral anticoagulant therapy always must follow a course of thrombolysis.

In patients with acute PE associated with hypotension (eg, systolic BP , 90 mm Hg) who do not have a high bleeding risk, we suggest systemically administered thrombolytic therapy over no such therapy (Grade 2C) .

3.Surgery for DVT Indications when anticoagulant therapy is ineffective unsafe, contraindicated. The major surgical procedures for DVT are clot removal and partial interruption of the inferior vena cava to prevent pulmonary embolism.

These pulmonary emboli removed at autopsy look like casts of the deep veins of the leg where they originated. This patient underwent a thrombectomy. The thrombus has been laid over the approximate location in the leg veins where it developed.

Operative Venous Thrombectomy for Acute DVT In patients with acute proximal DVT of the leg, we suggest anticoagulant therapy alone over operative venous thrombectomy (Grade 2C) .

4.Filters for DVT Indications for insertion of an inferior vena cava filter Pulmonary embolism with contraindication to anticoagulation Recurrent pulmonary embolism despite adequate anticoagulation

Controversial indications: Deep vein thrombosis with contraindication to anticoagulation Deep vein thrombosis in patients with pre-existing pulmonary hypertension Free floating thrombus in proximal vein Failure of existing filter device Post pulmonary embolectomy

Compression stockings (routinely recommended

PROPHYLAXIS Ideidentify any patiant who is at risk. Prevent dehydration. During operation avoid prolonged calf compression. Passive leg exercises should be encourged whilst patient on bed. Foot of bed should be elevated to increase venous return. Early mobilization should be rule for all surgical patients.

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