Summary Deep vein thrombosis (DVT) is a common complication that is caused by a blood clot originating in deep veins and propagating proximally. This condition most commonly presents in middle-aged and elderly adults with swelling and pain in the calf. Diagnosis is made in combination with a clinical examination that demonstrates calf pain and swelling, as well as advanced imaging (e.g., duplex ultrasound). Treatment of DVT is primarily anticoagulation to prevent further morbidity, and in some instances, thrombolytic therapy and/or surgical intervention is indicated. Introduction Introduction procedures associated with a greater risk of DVT spine fracture with paralysis elective total knee arthroplasty 2-3X greater rate of DVT than THA elective total hip arthroplasty no increased risk in patients with Factor V Leiden hip fracture polytrauma based on AAOS review, the rate of DVT does not correlate with PE or death following THA or TKA Epidemiology Incidence 80 cases per 100,000 per year 1 lower extremity case per 1,000 each year 2.5-5% of the population is affected Demographics rare in children typically >40 years of age unknown sex bias African American and White populations are at increased risk Location upper extremity lower extremity proximal location above knee distal location below knee axial muscular Risk factors immobilization mechanical compression trauma history of DVT surgery polycythemia vera thrombocytosis dehydration Etiology Pathophysiology mechanism virchow's triad hypercoagulable state venous stasis injury to endothelium pathoanatomy thrombin interaction with the endothelium stimulates cytokine production and leukocyte adhesion thrombus propagation is dependent on the balance between coagulation and thrombolytic pathways Associated conditions medical malignancy congestive heart failure destructive airway disease orthopedic patients undergoing surgery Anatomy Upper extremity deep veins radial ulnar brachial axillary subclavian internal jugular brachiocephalic Lower extremity proximal popliteal vein and proximal distal axial peroneal anterior tibial posterior tibial muscular intra-muscular soleal gastrocnemius Presentation History previous surgery state of hypercoagulability recent immobilization recent injury Symptoms common extremity swelling (70%) calf pain (50%) redness warmth Physical exam often more helpful than imaging lower extremity swelling (unilateral or bilateral) erythema and warmth of skin dilated veins tenderness with palpation Homan's sign is not very specific Imaging Contrast venography historical gold standard venous contrast with fluoroscopy invasive procedure with direct visualization of venous clot can be used when ultrasound is unavailable or inconclusive Ultrasonography complete duplex ultrasound first-line imaging modality non-invasive and inexpensive 96% sensitive, 97% specific; operator dependent routine duplex screening is not recommended findings non-compressible venous segment loss of phasic flow with Valsalva maneuver increased flow in superficial veins Advanced imaging Magnetic resonance direct thrombus imaging (MRDTI) MRI with contrast dye to visualize venous thrombus 90% sensitive, 90% specific not widely used alternative to duplex ultrasound CT venography CT scan with contrast dye to visualize venous thrombus 90% sensitive, 95% specific useful when pulmonary embolism is suspected or following an inconclusive ultrasound study Additional information for proximal DVTs (proximal to trifurcation) complete duplex ultrasound (96% sensitive, 97% specific) plethysmography (75% sensitive, 90% specific) CT (90% sensitive, 95% specific) Studies D-Dimer testing high sensitivity (low specificity) for VTE excludes VTE without the need for further testing among patients with a low clinical probability of PE not helpful post-injury or surgery levels > 500 ng/mL suggest the presence of PE Differential Cellulitis infectious laboratory findings Post-thrombotic syndrome history of DVT, chronic swelling, and venous stasis ulcers Ruptured Baker cyst ultrasound findings without a venous thrombus Trauma radiographs demonstrating an underlying fracture that is causing edema and pain Superficial thrombophlebitis cord-like superficial vein on exam with superficial venous thrombus on ultrasound Congestive heart failure notable medical history with chronic bilateral lower extremity peripheral edema Nephrotic syndrome notable medical history with chronic bilateral lower extremity peripheral edema Liver cirrhosis notable medical history with chronic bilateral lower extremity peripheral edema Treatment Nonoperative Oral anticoagulation therapy indications postoperative DVT above knee treatment for DVT below knee is controversial oral anticoagulation medications direct oral anticoagulants (DOACs) are first-line dabigatran, rivaroxaban, apixiban, and edoxaban, are recommended by the 2016 American College of Chest Physicians and 2014 and 2017 European Society of Cardiology guidelines for both DVT and PE LMWH enoxaparin (Lovenox) preferred in early postoperative period high bleeding risk Vitamin K antagonist Warfarin have to bridge with LMWH until INR is 2-3 preferred in patients with a mechanical heart valve duration isolated DVT standard recommendation 3 months of therapeutic anticoagulation with pulmonary embolism standard recommendation >3 months of therapeutic anticoagulation longer duration large clot burden persistent risk factors recurrent VTE when to treat >3 months unprovoked DVT recurrent DVT active malignancy paralysis or immobilization known thrombophilia thrombolytic therapy considered in those with life or limb-threatening PE or acute DVT associated with high risk of morbidity Operative vena cava filter placement indications preoperative identification of DVT in a patient with lower extremity or pelvic trauma who is high risk for DVT development see anticoagulation thrombectomy indications when anticoagulation alone is not effective thrombus with high risk of morbidity and mortality catheter-directed thrombolysis indications indicated as initial treatment recommended only for patients with threatened limb loss Complications Postthrombotic syndrome: chronic venous insufficiency venous HTN chronic skin issues (swelling, pain, pigmentation, ulceration, induration) recurrent DVT (4-8x higher after first DVT) Pulmonary emboli 1 in 1,000 cases annually diagnosis via advanced imaging and clinical exam treatment with oral/IV therapeutic anticoagulation with/without surgical intervention Excessive bleeding from anticoagulation medication from thrombolytic therapy