Deep vein thrombosis

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Deep-vein thrombosis, also known as deep-venous thrombosis (DTV), is the formation of a blood clot ("thrombus") in a deep vein. It commonly affects the leg veins, such as the femoral vein or the popliteal vein or the deep veins of the pelvis. Occasionally the veins of the arm are affected (known as Paget-Schrötter disease). Embolism and thrombosis is the more general class of pathologies of this kind.

Thrombi may develop first in the calf veins (calf vein thrombosis), "growing" in the direction of flow of the vein. DVTs are distinguished as being above or below the trifucation of the popliteal vein. Very extensive DVTs can extend into the iliac veins or the inferior vena cava. The risk of pulmonary embolism is higher in the presence of more extensive clots.

Epidemiology

DVTs occur in about 1 per 1000 persons per year. About 1-5% will die from the complications (i.e. pulmonary embolism).

DVT is much less common in the pediatric population. About 1 in 100,000 people under the age of 18 experiences deep vein thrombosis, possibly due to a child's high rate of heartbeats per minute, relatively active lifestyle when compared with adults, and fewer comorbodities (e.g. malignancy).

Cause/etiology

Virchow's triad

Many factors are involved in the formation of a thrombus (clot). Virchow's triad is a group of 3 factors known to affect clot formation: rate of flow, the consistency (thickness) of the blood, and qualities of the vessel wall. Among the risk factors are advanced age, obesity, infection, immobilization, female sex, use of oral contraceptives, tobacco usage and air travel ("economy class syndrome", a combination of immobility and relative dehydration) are some of the better-known causes.[1] Thrombophilia (tendency to develop thrombosis) often expresses itself with recurrent thromboses.

Underlying malignancy

DVT may be due to underlying malignancy, especially if the DVT is associated with older age, idiopathic DVT, bilateral thrombosis, or anemia.[2] These patients have a worse prognosis.

Genetics

A twin study found a genetic contribution to venous thromboembolism among men but not women.[3] Among men, the concordance rates for mono- and dizygotic twin pairs were 0.22 and 0.08.

Various single-nucleotide polymorphisms (SNPs) have been associated with DVT.[4]

Signs and symptoms

There may be no symptoms referrable to the location of the DVT, but the classical symptoms of DVT include pain, swelling and redness of the leg and dilatation of the surface veins. In up to 25% of all hospitalized patients, there may be some form of DVT, which often remains clinically inapparent (unless pulmonary embolism develops).

There are several techniques during physical examination to increase the detection of DVT, such as measuring the circumference of the affected and the contralateral limb at a fixed point (to objectivate edema), and palpating the venous tract, which is often tender. Physical examination is unreliable for excluding the diagnosis of deep vein thrombosis.

A careful history has to be taken considering risk factors (see below), including the use of estrogen-containing methods of hormonal contraception, recent long-haul flying, and a history of miscarriage (which is a feature of several disorders that can also cause thrombosis). A family history can reveal a hereditary factor in the development of DVT.

It is vital that the possibility of pulmonary embolism be included in the history, as this may warrant further investigation (see pulmonary embolism).

Complications As a complication, post-thrombotic syndrome can develop. Post-phlebitic syndrome occurs in 10% of patients with deep vein thrombosis (DVT). It presents with leg oedema, pain, nocturnal cramping, venous claudication, skin pigmentation, dermatitis and ulceration (usually on the medial aspect of the lower leg). In phlegmasia alba dolens, the leg is pale and cool with a diminished arterial pulse due to spasm. It usually results from acute occlusion of the iliac and femoral veins due to DVT. In phlegmasia cerulea dolens, there is an acute and nearly total venous occlusion of the entire extremity outflow, including the iliac and femoral veins. The leg is usually painful, cyanosed and oedematous. Venous gangrene may supervene.

Diagnosis

Homan's sign is used in clinical practice to diagnose DVT.

The gold standard is intravenous venography, which involves injecting a peripheral vein of the affected limb with a contrast agent and taking X-rays, to reveal whether the venous supply has been obstructed. Because of its invasiveness, this test is rarely performed.

Impedance plethysmography and Doppler ultrasonography are non-invasive alternatives.

Probability scoring

Wells rule

The best studied clinical prediction rule is the Wells rule; however, use of the Wells rule is complicated by the rule having been modified over time. This has resulted in guidelines recommending use of outdated versions of the Wells rule.[5] The rule was introduced in 1995.[6]

2003[7]-2006[8] Wells 10 point rule:
  1. Active cancer (treatment within last 6 months or palliative) -- 1 point
  2. Calf swelling >3cm compared to other calf (measured 10cm below tibial tuberosity) -- 1 point
  3. Collateral superficial veins (non-varicose) -- 1 point
  4. Pitting edema (confined to symptomatic leg) -- 1 point
  5. Swelling of entire leg - 1 point
  6. Localized pain along distribution of deep venous system -- 1 point
  7. Paralysis, paresis, or recent cast immobilization of lower extremities -- 1 point
  8. Recently bedridden > 3 days, or major surgery requiring regional or general anesthetic in past 12 weeks -- 1 point
  9. Previously documented DVT -- 1 point
  10. Alternative diagnosis at least as likely -- Subtract 2 points

Interpretation:

Score of 2 or higher - deep vein thrombosis is likely. Consider imaging the leg veins.
Score of less than 2 - deep vein thrombosis is unlikely. Consider blood test such as d-dimer test to further rule out deep vein thrombosis.

1995 Original Wells 12 point rule:[6]
Major points

  • Active cancer (treatment ongoing or within previous 6 months or palliative)
  • Paralysis, paresis. or recent plaster irnmobilisation of the lower extremities
  • Recently bedridden >3 days and/or major surgery within 4 weeks
  • Localised tenderness along tl’e distribution of the deep venous system
  • Thigh and calf swollen (should be measured)
  • Calf swelling 3cm >symptornless side (measured 10cm below tibial tuberosity
  • Strong family history of (NT (2 first degree relatives with history of CVI)

Minor points

  • History of recent trauma C 60 days) to the symptomatic leg
  • Pitting oedema; symptomatic leg only
  • Dilated superficial veins (non-varicose) in symptomatic leg only
  • Hospitisation within previous 6 months
  • Erythema

1997 Wells 9 point rule:[9]

  1. Active cancer (treatment ongoing or within previous 6 months or palliative) - 1 point
  2. Paralysis, paresis, or recent plaster immobilisation of the lower extremities - 1 point
  3. Recently bedridden for more than 3 days or major surgery, within 4 weeks - 1 point
  4. Localised tenderness along the distribution of the deep venous system - 1 point
  5. Entire leg swollen - 1 point
  6. Calf swelling by more than 3 cm when compared with the asymptomatic leg (measured 10 cm below tibial tuberosity) - 1 point
  7. Pitting oedema (greater in the symptomatic leg) - 1 point
  8. Collateral superficial veins (non-varicose) - 1 point
  9. Alternative diagnosis as likely or greater than that of deep-vein thrombosis - subtract 2 points
Interpretation: low (score 0), medium (score of 1 or 2), or high (score 3)

In 2005 a large study found that the 1997 Wells score failed to adequately exclude DVT in primary care patients.[10] Unfortunately, the 2005 study was completed in March, 2003, 6 months prior to publication of the 2003 revision by Wells to his rule in which he added a 10th variable.

In 2003, Wells published a 10 point rule that adds a point for history of previous DVT (yellow box).[7] In 2006, Wells reviewed the available clinical prediction rules for DVT and did not further modify the 2003 rule.[8]

Based one his 2003 study, Wells recommends that DVT is excluded only when the 10-point score is < 2 and the D-dimer is negative.[8]

AMUSE rule

Because of concerns about the failed study in 2005 of the older, 9-point 1997 Wells rule (note that the current Wells rule has 10 points)[10], the Amsterdam Maastricht Utrecht Study on thromboEmbolism (AMUSE) Investigators developed a rule with 7 clinical variable plus the D-dimer.[11][12] Patients with a score of 3 or less are considered normal; patients with a score of 4 should receive ultrasonography.

  • Use of hormonal contraceptives
  • Active cancer in past 6 mo
  • Surgery in previous month
  • Absence of leg trauma
  • Distention of collateral leg veins
  • Difference in calf circumference ≥ 3 cm (2 points)
  • Abnormal d-dimer assay (6 points)

Patients with score ≥ 4 should receive ultrasonography of the leg.


This rule has not been externally validated by independent research groups.

Imaging the leg veins

Ultrasonography

Compression B-mode ultrasonography[13] scanning of the leg veins, combined with Duplex Doppler ultrasonography[14] (to determine blood flow), can reveal a thrombus.

Distinguishing acute versus chronic thrombosis with Duplex Doppler ultrasonography has been examined in one study of 103 examination in 101 patients:[15]

In this study "no results were false-positive for acute DVT due to the changes of chronic DVT."

Whole leg ultrasonography
Risk outcomes following a single negative whole-leg compression ultrasonography according to a systematic review.[16]
Wells score Death (%) from embolism and thrombosis (95% CI)
All patients 0.7%
Low risk 0.3% (0 to 0.7%)
Intermediate risk 0.8% (0 to 1.8%)
High risk 2.5% (0 to 7.1%)

Either whole leg Doppler ultrasonography or serial 2-point ultrasonography plus D-dimer are equivalent strategies according to a randomized controlled trial[17] that was included in the meta-analysis.

An uncontrolled cohort study found that anticoagulation can be safely withheld in patients with normal whole leg Doppler ultrasonography.[18]

Venography

Venography can determine acute versus chronic thrombosis:[15]

  • Acute thrombosis is suggested by any of:
    • "constant filling defect or thrombus was identified"
    • "persistent nonfilling of a venous segment despite adequate technique"
    • " abrupt termination of the opaque column of contrast material in a venous segment"
  • Chronic thrombosis is suggested by any of:
    • "irregular walls suggestive of retracted adherent thrombus"
    • "a lumen smaller than expected"
    • "numerous well-developed adjacent collateral veins"
    • "Valvular incompetence in the deep veins was considered further evidence of chronic DVT but was not required for the diagnosis."

Blood tests

In a low-probability situation, current practice is to commence investigations by testing for D-dimer levels. This cross-linked fibrin degradation product is an indication that thrombosis is occurring, and that the blood clot is being dissolved by plasmin. A low D dimer level should prompt other possible diagnoses (such as a ruptured Baker's cyst, if this has not been considered as part of the history).

Other blood tests usually performed at this point are:

Differential diagnosis

Rupture of the tendon of the plantaris muscle may mimic deep venous thrombosis.[19]

Prophylaxis (Prevention)

Clinical practice guidelines by the American College of Chest Physicians (ACCP) provide recommendations on DVT prophylaxis in hospitalized patients [20].

New clinical practice guidelines by the American College of Chest Physicians (ACCP) were published in 2008.[21]

Compression devices that are mobile may be effective.[22]

Rosuvastatin, a hydroxymethylglutaryl-coenzyme A reductase inhibitor (statin), may reduce embolism and thrombosis according to the Jupiter randomized controlled trial.[23]

General Medical Inpatients

Regarding general medical inpatients the 2008 guidelines state:

  • "For acutely ill medical patients admitted to hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, including active cancer, previous VTE, sepsis, acute neurologic disease, or inflammatory bowel disease, we recommend thromboprophylaxis with LMWH (Grade 1A), LDUH (Grade 1A), or fondaparinux (Grade 1A)."

Enoxaparin or unfractionated heparin may be used.[24] LMWH may be more effective than UFH. If UFH heparin is used, 5000 U 3 times daily may be more effective[25]

Since publication of the ACCP guidelines, an additional randomized controlled trial [26] and meta-analysis [27] including the trial have been published. The meta-analysis concluded " Anticoagulant prophylaxis is effective in preventing symptomatic venous thromboembolism during anticoagulant prophylaxis in at-risk hospitalized medical patients. Additional research is needed to determine the risk for venous thromboembolism in these patients after prophylaxis has been stopped." With regards to which patients are at risk, most studies in the meta-analysis were of patients with New York Heart Association Functional Classification (NYHA) III-IV heart failure. Regarding patients at lesser risk of DVT, the trial above[26] and an earlier trial[28] are relevant yet inconclusive.

Oncology patients

According to a clinical practice guideline by the American Society of Clinical Oncology, "all hospitalized cancer patients should be considered for VTE prophylaxis with anticoagulants in the absence of bleeding or other contraindications."[29]

For oncology patients who have had a thrombus, consider lifelong prophylaxis with enoxaparin 1.5 mg/kg per day.[30]

Surgery Patients

The risk of DVT after surgery may persist up to 12 weeks.[31]

Hip or knee surgery

Clinical practice guidelines by the American College of Chest Physicians[32] and the American Academy of Orthopaedic Surgeons[33] address prevention. Unfortunately, these guidelines have substantial conflict.[34]

Low molecular weight heparins may provide better anticoagulation for prophylaxis of deep venous thrombosis among orthopedic patients than direct thrombin inhibitors because the latter may increase complications.[35] However, if anticoagulation is started before surgery, direct thrombin inhibitors may be more effective.

Extending anticoagulation (25-35 days) with low molecular weight heparin, such as enoxaparin 30 to 40 mg subcutaneously once daily can reduce symptomatic DVT in one of every 45 patients treated and can reduce any (symptomatic or assymptomatic) DVT in one of every 8 patients treated.[36] As these studies were short term, it is likely that some patients with asymptomatic DVT progress to chronic venous insufficiency.

Even knee arthroscopic meniscectomy may benefit from low molecular weight heparin.[37]

Factor Xa inhibitors

Travelers

Travel may[42] or may not[43] lead to DVT according to meta-analyses.

Trials suggests that wearing compression socks while traveling also reduces the incidence of thrombosis in people on long haul flights. A randomized study in 2001 compared two sets of long haul airline passengers, one set wore travel compression hosiery the others did not. The passengers were all scanned and blood tested to check for the incidence of DVT. The results showed that asymptomatic DVT occurred in 10% of the passengers who did not wear compression socks. The group wearing compression had no DVTs. The authors concluded that wearing elastic compression hosiery reduces the incidence of DVT in long haul airline passengers.[44].

Therapy

Treatment options have been reviewed.[45]

  • Anticoagulation is the usual treatment for DVT. In general, patients are initiated on a brief course (i.e., less than a week) of heparin treatment while they start on a 3- to 6-month course of warfarin (or related vitamin K inhibitors). Low molecular weight heparin (LMWH) is preferred,[47] though unfractionated heparin is given in patients who have a contraindication to LMWH (e.g., renal failure or imminent need for invasive procedure). Rivaroxaban may provide oral treatment.[48]
Regarding the duration of anticoagulation, see embolism and thrombosis: treatment.
  • Elastic compression stockings should be routinely applied.[47] The stockings in almost all trials were stronger than routine anti-embolism stockings and created either 20-30 mm Hg or 30-40 mm Hg. Most trials used knee-high stockings. A meta-analysis of randomized controlled trials by the Cochrane Collaboration showed reduced incidence of post-phlebitic syndrome.[49] The number needed to treat is quite potent at 4 to 5 patients need to prevent one case of post-phlebitic syndrome.[50] Compression stocking can cause local complications.[51]
  • Inferior vena cava filter also referred to as a Greenfield filter, reduces pulmonary embolism[52] and is an option for patients with an absolute contraindication to anticoagulant treatment (e.g., cerebral hemorrhage) or those rare patients who have objectively documented recurrent PEs while on anticoagulation. However these filters are themselves potential foci of thrombosis,[53] IVC filters are viewed as a temporizing measure for preventing life-threatening pulmonary embolism.
  • Hospitalization should be considered in patients with more than two of the following risk factors as these patients may have more risk of complications during treatment[54]:
    • bilateral DVT, renal insufficiency, body weight <70 kg, recent immobility, chronic heart failure, and cancer

Oncology patients

A clinical practice guideline published in 2004 by the American College of Chest Physicians states:[55]

"for patients with DVT and cancer, we recommend LMWH for the first 3 to 6 months of long-term anticoagulant therapy (Grade 1A). For these patients, we recommend anticoagulant therapy indefinitely or until the cancer is resolved".

A clinical practice guideline published in 2007 by the American Society of Clinical Oncology states:[29]

"1) low molecular weight heparin LMWH is the preferred approach for the initial 5 to 10 days of anticoagulant treatment of the cancer patient with established VTE, 2) LMWH given for at least 6 months is also the preferred approach for long-term anticoagulant therapy. Vitamin K antagonists with a targeted INR of 2 to 3 are acceptable for long-term therapy when LMWH is not available. 3) After 6 months, indefinite anticoagulant therapy should be considered for selected patients with active cancer, such as those with metastatic disease and those receiving chemotherapy. This recommendation is based on Panel consensus in the absence of clinical trials data."

Determining when to stop treatment

D-Dimer

An abnormal D-dimer level at the end of treatment might signal the need for continued anticoagulation with warfarin among patients with embolism and thrombosis such as a first unprovoked pulmonary embolism. If the D-dimer is abnormal, anticoaguation should be continued, if the D-dimer is normal, the duration of treatment is uncertain.[56] In an observation study that collected the D-dimer before stopping anticoagulation, the D-dimer was not as predictive.[57]

Ultrasonography

Ultrasonography, using the following protocol may[58] or may not[59] help determine when to stop anticoaguation[58]:

"If veins had not recanalized, we invited patients to have further ultrasonography after 3 and 9 months in patients with secondary DVT and after 3, 9, 15, and 21 months in those with unprovoked DVT. Anticoagulation was discontinued when the veins had recanalized, along with further ultrasonography"

Prognosis

Postthrombotic syndrome

Postthrombotic syndrome along with postphlebitic syndrome are forms of venous insufficiency. Postthrombotic syndrome is a "condition caused by one or more episodes of deep vein thrombosis, usually the blot clots are lodged in the legs. Clinical features include edema; pain; aching; heaviness; and muscle cramp in the leg. When severe leg swelling leads to skin breakdown, it is called venous stasis ulcer."[60][61]

The incidence of postthrombotic syndrome is 76.1 per 100,000 person-years.[62] Regarding the etiology of the postthrombotic syndrome, about 40% are from prior DVT[63] although only 25% of patients report a prior diagnosis of DVT[62]. This suggests nearly half of the prior DVTs were undiagnosed.

Natural history of a diagnosed DVT

The natural history of a diagnosed DVT is as follows. After two years, the probability of postthrombotic syndrome is:[64]

  • No postthrombotic syndrome 60%
  • Mild postthrombotic syndrome 26%
  • Moderate postthrombotic syndrome 11%
  • Severe postthrombotic syndrome 3%

Risk factors include:

  • Prior ipsilateral DVT
  • Obesity
  • Female gender
  • Older age

After 5 to 10 years: One cohort reported 28% incidence (using a definition that required more significant symptoms)at five years.[65]

Among patients 6 to 8 years after a DVT, "42% reported pain, swelling, or discoloration."[66]

After 10 to 20 years: Although after 20 years, only 26.8% of patients will have sought medical care and be diagnosed with late complications of DVT[67], when patients are actively studied 10-20 years after their initial thrombosis, 80% have some signs of postthrombotic syndrome.[68]

Recurrent DVT

Risk factors for recurrence if anticoagulation is stopped are:[69]

  • post-thrombotic symptoms such as "hyperpigmentation, edema or redness of either leg"
  • D-dimer > or = 250 microg/L while taking warfarin> Other studies suggest the D-dimer should be checked after stopping warfarin.
  • body mass index > or = 30 kg/m(2)
  • age > or = 65 years
  • male gender


References

  1. ↑ Tsai A, Cushman M, Rosamond W, Heckbert S, Polak J, Folsom A (2002). "Cardiovascular risk factors and venous thromboembolism incidence: the longitudinal investigation of thromboembolism etiology.". Arch Intern Med 162 (10): 1182-9. PMID 12020191.
  2. ↑ Trujillo-Santos J, Prandoni P, Rivron-Guillot K, et al (2008). "Clinical outcome in patients with venous thromboembolism and hidden cancer: findings from the RIETE Registry". J Thromb Haemost 6 (2): 251–255. DOI:10.1111/j.1538-7836.2007.02837.x. PMID 18021305. Research Blogging.
  3. ↑ Larsen TB, Sørensen HT, Skytthe A, Johnsen SP, Vaupel JW, Christensen K (2003). "Major genetic susceptibility for venous thromboembolism in men: a study of Danish twins". Epidemiology 14 (3): 328-32. PMID 12859034. [e]
  4. ↑ Bezemer, I. D., Bare, L. A., Doggen, C. J. M., Arellano, A. R., Tong, C., Rowland, C. M., et al. (2008). Gene variants associated with deep vein thrombosis, JAMA, 299(11), 1306-1314. DOI:10.1001/jama.299.11.1306.
  5. ↑ Qaseem A, Snow V, Barry P, et al (2007). "Current diagnosis of venous thromboembolism in primary care: a clinical practice guideline from the American Academy of Family Physicians and the American College of Physicians". Ann. Intern. Med. 146 (6): 454–8. PMID 17371890. [e]
  6. ↑ 6.0 6.1 Wells PS, Hirsh J, Anderson DR, et al (1995). "Accuracy of clinical assessment of deep-vein thrombosis". Lancet 345 (8961): 1326–30. PMID 7752753. [e]
  7. ↑ 7.0 7.1 Wells PS, Anderson DR, Rodger M, et al (2003). "Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis". N. Engl. J. Med. 349 (13): 1227–35. DOI:10.1056/NEJMoa023153. PMID 14507948. Research Blogging.
  8. ↑ 8.0 8.1 8.2 Scarvelis D, Wells PS (2006). "Diagnosis and treatment of deep-vein thrombosis". CMAJ 175 (9): 1087–92. DOI:10.1503/cmaj.060366. PMID 17060659. Research Blogging.
  9. ↑ Wells PS, Anderson DR, Bormanis J, et al (1997). "Value of assessment of pretest probability of deep-vein thrombosis in clinical management". Lancet 350 (9094): 1795–8. DOI:10.1016/S0140-6736(97)08140-3. PMID 9428249. Research Blogging.
  10. ↑ 10.0 10.1 Oudega R, Hoes AW, Moons KG (2005). "The Wells rule does not adequately rule out deep venous thrombosis in primary care patients". Ann. Intern. Med. 143 (2): 100–7. PMID 16027451. [e] Cite error: Invalid <ref> tag; name "pmid16027451" defined multiple times with different content
  11. ↑ Toll, DB et al. 2008. “A new diagnostic rule for deep vein thrombosis: safety and efficiency in clinically relevant subgroups.” Fam. Pract. 2008. http://fampra.oxfordjournals.org/cgi/content/full/cmm075v1
  12. ↑ Büller HR, Ten Cate-Hoek AJ, Hoes AW, et al (February 2009). "Safely ruling out deep venous thrombosis in primary care". Ann. Intern. Med. 150 (4): 229–35. PMID 19221374. [e]
  13. ↑ Lensing AW, Prandoni P, Brandjes D, Huisman PM, Vigo M, Tomasella G et al. (1989). "Detection of deep-vein thrombosis by real-time B-mode ultrasonography.". N Engl J Med 320 (6): 342-5. PMID 2643771.
  14. ↑ White RH, McGahan JP, Daschbach MM, Hartling RP (1989). "Diagnosis of deep-vein thrombosis using duplex ultrasound.". Ann Intern Med 111 (4): 297-304. PMID 2667418.
  15. ↑ 15.0 15.1 Lewis BD, James EM, Welch TJ, Joyce JW, Hallett JW, Weaver AL (1994). "Diagnosis of acute deep venous thrombosis of the lower extremities: prospective evaluation of color Doppler flow imaging versus venography.". Radiology 192 (3): 651-5. PMID 8058929.
  16. ↑ Johnson SA, Stevens SM, Woller SC, Lake E, Donadini M, Cheng J et al. (2010). "Risk of deep vein thrombosis following a single negative whole-leg compression ultrasound: a systematic review and meta-analysis.". JAMA 303 (5): 438-45. DOI:10.1001/jama.2010.43. PMID 20124539. Research Blogging.
  17. ↑ Bernardi E, Camporese G, Büller HR, et al (October 2008). "Serial 2-point ultrasonography plus D-dimer vs whole-leg color-coded Doppler ultrasonography for diagnosing suspected symptomatic deep vein thrombosis: a randomized controlled trial". JAMA : the journal of the American Medical Association 300 (14): 1653–9. DOI:10.1001/jama.300.14.1653. PMID 18840838. Research Blogging.
  18. ↑ Stevens SM, Elliott CG, Chan KJ, Egger MJ, Ahmed KM (2004). "Withholding anticoagulation after a negative result on duplex ultrasonography for suspected symptomatic deep venous thrombosis.". Ann Intern Med 140 (12): 985-91. PMID 15197015.
  19. ↑ Lopez, Gregory J; Hoffman RS, Davenport M. "Plantaris rupture: A mimic of deep venous thrombosis". Journal of Emergency Medicine. DOI:10.1016/j.jemermed.2007.12.027. Retrieved on 2009-01-16. Research Blogging.
  20. ↑ Geerts WH, Pineo GF, Heit JA, Bergqvist D, Lassen MR, Colwell CW, Ray JG. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004 Sep;126 (3 Suppl):338S-400S. http://www.chestjournal.org/cgi/content/full/126/3_suppl/338S PMID 15383478
  21. ↑ Geerts, William H.; David Bergqvist, Graham F. Pineo, John A. Heit, Charles M. Samama, Michael R. Lassen, Clifford W. Colwell (2008-06-01). "Prevention of Venous Thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)". Chest 133 (6_suppl): 381S-453. DOI:10.1378/chest.08-0656. Retrieved on 2008-06-24. Research Blogging.
  22. ↑ Colwell CW, Froimson MI, Mont MA, Ritter MA, Trousdale RT, Buehler KC et al. (2010). "Thrombosis prevention after total hip arthroplasty: a prospective, randomized trial comparing a mobile compression device with low-molecular-weight heparin.". J Bone Joint Surg Am 92 (3): 527-35. DOI:10.2106/JBJS.I.00047. PMID 20194309. Research Blogging.
  23. ↑ Glynn RJ, Danielson E, Fonseca FA, et al (March 2009). "A Randomized Trial of Rosuvastatin in the Prevention of Venous Thromboembolism". N. Engl. J. Med.. DOI:10.1056/NEJMoa0900241. PMID 19329822. Research Blogging.
  24. ↑ King CS, Holley AB, Jackson JL, Shorr AF, Moores LK (2007). "Twice vs three times daily heparin dosing for thromboembolism prophylaxis in the general medical population: A metaanalysis". Chest 131 (2): 507–16. PMID 17296655.
  25. ↑ Wein L et al. Pharmacological Venous Thromboembolism Prophylaxis in Hospitalized Medical Patients. Arch Intern med 2007;167:1476-1486. PMID 17646601
  26. ↑ 26.0 26.1 Lederle FA, Sacks JM, Fiore L, Landefeld CS, Steinberg N, Peters RW, Eid AA, Sebastian J, Stasek JE Jr, Fye CL. The prophylaxis of medical patients for thromboembolism pilot study. Am J Med. 2006;119:54-9. PMID 16431185
  27. ↑ Dentali F, Douketis JD, Gianni M, Lim W, Crowther MA. Meta-analysis: anticoagulant prophylaxis to prevent symptomatic venous thromboembolism in hospitalized medical patients. Ann Intern Med. 2007;146:278-88. PMID 17310052
  28. ↑ Gärdlund B (1996). "Randomised, controlled trial of low-dose heparin for prevention of fatal pulmonary embolism in patients with infectious diseases. The Heparin Prophylaxis Study Group". Lancet 347 (9012): 1357–61. PMID 8637340. [e]
  29. ↑ 29.0 29.1 Lyman GH, Khorana AA, Falanga A, et al (2007). "American Society of Clinical Oncology Guideline: Recommendations for Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer". DOI:10.1200/JCO.2007.14.1283. PMID 17968019. Research Blogging. Cite error: Invalid <ref> tag; name "pmid17968019" defined multiple times with different content
  30. ↑ Akl EA, Barba M, Rohilla S, et al (2008). "Anticoagulation for the long term treatment of venous thromboembolism in patients with cancer". Cochrane Database Syst Rev (2): CD006650. DOI:10.1002/14651858.CD006650.pub2. PMID 18425959. Research Blogging.
  31. ↑ Sweetland S, Green J, Liu B, Berrington de González A, Canonico M, Reeves G et al. (2009). "Duration and magnitude of the postoperative risk of venous thromboembolism in middle aged women: prospective cohort study.". BMJ 339: b4583. DOI:10.1136/bmj.b4583. PMID 19959589. Research Blogging.
  32. ↑ Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR et al. (2008). "Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).". Chest 133 (6 Suppl): 381S-453S. DOI:10.1378/chest.08-0656. PMID 18574271. Research Blogging. Summary at the National Guidelines Clearinghouse
  33. ↑ (2007) American Academy of Orthopaedic Surgeons Clinical Guideline on Prevention of Pulmonary Embolism in Patients Undergoing Total Hip or Knee Arthroplasty Summary at the National Guidelines Clearinghouse
  34. ↑ Eikelboom JW, Karthikeyan G, Fagel N, Hirsh J (2009). "American Association of Orthopedic Surgeons and American College of Chest Physicians guidelines for venous thromboembolism prevention in hip and knee arthroplasty differ: what are the implications for clinicians and patients?". Chest 135 (2): 513-20. DOI:10.1378/chest.08-2655. PMID 19201714. Research Blogging.
  35. ↑ Salazar CA, Malaga G, Malasquez G (2010). "Direct thrombin inhibitors versus vitamin K antagonists or low molecular weight heparins for prevention of venous thromboembolism following total hip or knee replacement.". Cochrane Database Syst Rev 4: CD005981. DOI:10.1002/14651858.CD005981.pub2. PMID 20393944. Research Blogging.
  36. ↑ Hull RD, Pineo GF, Stein PD, et al (November 2001). "Extended out-of-hospital low-molecular-weight heparin prophylaxis against deep venous thrombosis in patients after elective hip arthroplasty: a systematic review". Annals of internal medicine 135 (10): 858–69. PMID 11712876. [e]
  37. ↑ Camporese G, Bernardi E, Prandoni P, Noventa F, Verlato F, Simioni P et al. (2008). "Low-molecular-weight heparin versus compression stockings for thromboprophylaxis after knee arthroscopy: a randomized trial.". Ann Intern Med 149 (2): 73-82. PMID 18626046. Review in: ACP J Club. 2008 Dec 16;149(6):10
  38. ↑ Eriksson BI, Bauer KA, Lassen MR, Turpie AG (November 2001). "Fondaparinux compared with enoxaparin for the prevention of venous thromboembolism after hip-fracture surgery". The New England journal of medicine 345 (18): 1298–304. PMID 11794148. [e]
  39. ↑ Lassen MR, Ageno W, Borris LC, et al (June 2008). "Rivaroxaban versus enoxaparin for thromboprophylaxis after total knee arthroplasty". The New England journal of medicine 358 (26): 2776–86. DOI:10.1056/NEJMoa076016. PMID 18579812. Research Blogging.
  40. ↑ Eriksson BI, Borris LC, Friedman RJ, et al (June 2008). "Rivaroxaban versus enoxaparin for thromboprophylaxis after hip arthroplasty". The New England journal of medicine 358 (26): 2765–75. DOI:10.1056/NEJMoa0800374. PMID 18579811. Research Blogging.
  41. ↑ Kakkar AK, Brenner B, Dahl OE, et al (July 2008). "Extended duration rivaroxaban versus short-term enoxaparin for the prevention of venous thromboembolism after total hip arthroplasty: a double-blind, randomised controlled trial". Lancet 372 (9632): 31–9. DOI:10.1016/S0140-6736(08)60880-6. PMID 18582928. Research Blogging. (this trial compared rivaroxaban to short-term enoxaparin
  42. ↑ Chandra D, Parisini E, Mozaffarian D (2009). "Meta-analysis: travel and risk for venous thromboembolism.". Ann Intern Med 151 (3): 180-90. PMID 19581633.
  43. ↑ Beam DM, Courtney DM, Kabrhel C, Moore CL, Richman PB, Kline JA (2009). "Risk of thromboembolism varies, depending on category of immobility in outpatients.". Ann Emerg Med 54 (2): 147-52. DOI:10.1016/j.annemergmed.2008.10.033. PMID 19135280. Research Blogging.
  44. ↑ Scurr JH, Machin SJ, Bailey-King S, Mackie IJ, McDonald S, Smith PD (2001). "Frequency and prevention of symptomless deep-vein thrombosis in long-haul flights: a randomised trial.". Lancet 357 (9267): 1485-9. DOI:10.1016/S0140-6736(00)04645-6. PMID 11377600. Research Blogging.
  45. ↑ Bates SM, Ginsberg JS (July 2004). "Clinical practice. Treatment of deep-vein thrombosis". N. Engl. J. Med. 351 (3): 268–77. DOI:10.1056/NEJMcp031676. PMID 15254285. Research Blogging.
  46. ↑ Watson L, Armon M. "Thrombolysis for acute deep vein thrombosis". Cochrane Database Syst Rev: CD002783. PMID 15495034.
  47. ↑ 47.0 47.1 Snow V et al (2007). "Management of Venous Thromboembolism: A Clinical Practice Guideline from the American College of Physicians and the American Academy of Family Physicians". Ann Intern Med 146 (3). Cite error: Invalid <ref> tag; name "pmid0000" defined multiple times with different content
  48. ↑ Buller HR, Lensing AW, Prins MH, et al (September 2008). "A dose-ranging study evaluating once-daily oral administration of the factor Xa inhibitor rivaroxaban in the treatment of patients with acute symptomatic deep vein thrombosis: the Einstein-DVT Dose-Ranging Study". Blood 112 (6): 2242–7. DOI:10.1182/blood-2008-05-160143. PMID 18621928. Research Blogging.
  49. ↑ Kolbach D, Sandbrink M, Hamulyak K, Neumann H, Prins M. "Non-pharmaceutical measures for prevention of post-thrombotic syndrome". Cochrane Database Syst Rev: CD004174. DOI:10.1002/14651858.CD004174.pub2. PMID 14974060. Research Blogging.
  50. ↑ Kakkos S, Daskalopoulou S, Daskalopoulos M, Nicolaides A, Geroulakos G (2006). "Review on the value of graduated elastic compression stockings after deep vein thrombosis". Thromb Haemost 96 (4): 441-5. PMID 17003920.
  51. ↑ CLOTS Trials Collaboration. Dennis M, Sandercock PA, Reid J, Graham C, Murray G et al. (2009). "Effectiveness of thigh-length graduated compression stockings to reduce the risk of deep vein thrombosis after stroke (CLOTS trial 1): a multicentre, randomised controlled trial.". Lancet 373 (9679): 1958-65. DOI:10.1016/S0140-6736(09)60941-7. PMID 19477503. PMC PMC2692021. Research Blogging. Review in: Ann Intern Med. 2009 Oct 20;151(8):JC4-9
  52. ↑ Decousus H, Leizorovicz A, Parent F, Page Y, Tardy B, Girard P, Laporte S, Faivre R, Charbonnier B, Barral F, Huet Y, Simonneau G (1998). "A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prévention du Risque d'Embolie Pulmonaire par Interruption Cave Study Group". N Engl J Med 338 (7): 409-15. PMID 9459643.
  53. ↑ PREPIC Study Group (2005). "Eight-year follow-up of patients with permanent vena cava filters in the prevention of pulmonary embolism: the PREPIC (Prevention du Risque d'Embolie Pulmonaire par Interruption Cave) randomized study.". Circulation 112 (3): 416-22. DOI:10.1161/CIRCULATIONAHA.104.512834. PMID 16009794. Research Blogging. Review in: ACP J Club. 2006 Jan-Feb;144(1):18
  54. ↑ Trujillo-Santos J, Herrera S, Page MA, et al (2006). "Predicting adverse outcome in outpatients with acute deep vein thrombosis. findings from the RIETE Registry". J. Vasc. Surg. 44 (4): 789-93. DOI:10.1016/j.jvs.2006.06.032. PMID 16926081. Research Blogging.
  55. ↑ Büller HR, Agnelli G, Hull RD, Hyers TM, Prins MH, Raskob GE (2004). "Antithrombotic therapy for venous thromboembolic disease: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy". Chest 126 (3 Suppl): 401S–428S. DOI:10.1378/chest.126.3_suppl.401S. PMID 15383479. Research Blogging.
  56. ↑ Palareti G, Cosmi B, Legnani C, et al (2006). "D-dimer testing to determine the duration of anticoagulation therapy". N. Engl. J. Med. 355 (17): 1780-9. DOI:10.1056/NEJMoa054444. PMID 17065639. Research Blogging.
  57. ↑ Rodger MA, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, et al. [Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy http://www.cmaj.ca/cgi/content/full/179/5/417]. CMAJ. 2008 Aug 26;179(5):417-426.
  58. ↑ 58.0 58.1 Prandoni, Paolo; Martin H. Prins, Anthonie W.A. Lensing, Angelo Ghirarduzzi, Walter Ageno, Davide Imberti, Gianluigi Scannapieco, Giovanni B. Ambrosio, Raffaele Pesavento, Stefano Cuppini, Roberto Quintavalla, Giancarlo Agnelli, for the AESOPUS Investigators (2009-05-05). "Residual Thrombosis on Ultrasonography to Guide the Duration of Anticoagulation in Patients With Deep Venous Thrombosis: A Randomized Trial". Ann Intern Med 150 (9): 577-585. PMID 19414836. Retrieved on 2009-05-06.
  59. ↑ Robinson KS, Anderson DR, Gross M, et al. (September 1997). "Ultrasonographic screening before hospital discharge for deep venous thrombosis after arthroplasty: the post-arthroplasty screening study. A randomized, controlled trial". Ann. Intern. Med. 127 (6): 439–45. PMID 9313000. [e]
  60. ↑ Anonymous (2024), Postthrombotic syndrome (English). Medical Subject Headings. U.S. National Library of Medicine.
  61. ↑ Bergan JJ, Schmid-Schönbein GW, Smith PD, Nicolaides AN, Boisseau MR, Eklof B (August 2006). "Chronic venous disease". N. Engl. J. Med. 355 (5): 488–98. DOI:10.1056/NEJMra055289. PMID 16885552. Research Blogging.
  62. ↑ 62.0 62.1 Heit JA, Rooke TW, Silverstein MD, et al (May 2001). "Trends in the incidence of venous stasis syndrome and venous ulcer: a 25-year population-based study". J. Vasc. Surg. 33 (5): 1022–7. DOI:10.1067/mva.2001.113308. PMID 11331844. Research Blogging.
  63. ↑ Train JS, Schanzer H, Peirce EC, Dan SJ, Mitty HA (August 1987). "Radiological evaluation of the chronic venous stasis syndrome". JAMA 258 (7): 941–4. PMID 3613024. [e]
  64. ↑ Kahn, Susan R.; Ian Shrier, Jim A. Julian, Thierry Ducruet, Louise Arsenault, Marie-Jose Miron, Andre Roussin, Sylvie Desmarais, France Joyal, Jeannine Kassis, Susan Solymoss, Louis Desjardins, Donna L. Lamping, Mira Johri, Jeffrey S. Ginsberg (2008-11-18). "Determinants and Time Course of the Postthrombotic Syndrome after Acute Deep Venous Thrombosis". Ann Intern Med 149 (10): 698-707. Retrieved on 2008-11-18.
  65. ↑ Prandoni P, Lensing AW, Cogo A, et al (July 1996). "The long-term clinical course of acute deep venous thrombosis". Ann. Intern. Med. 125 (1): 1–7. PMID 8644983. [e]
  66. ↑ Beyth RJ, Cohen AM, Landefeld CS (May 1995). "Long-term outcomes of deep-vein thrombosis". Arch. Intern. Med. 155 (10): 1031–7. PMID 7748045. [e]
  67. ↑ Mohr DN, Silverstein MD, Heit JA, Petterson TM, O'Fallon WM, Melton LJ (December 2000). "The venous stasis syndrome after deep venous thrombosis or pulmonary embolism: a population-based study". Mayo Clin. Proc. 75 (12): 1249–56. PMID 11126832. [e]
  68. ↑ Ziegler S, Schillinger M, Maca TH, Minar E (January 2001). "Post-thrombotic syndrome after primary event of deep venous thrombosis 10 to 20 years ago". Thromb. Res. 101 (2): 23–33. DOI:10.1016/S0049-3848(00)00370-4. PMID 11342203. Research Blogging.
  69. ↑ Rodger MA, Kahn SR, Wells PS, et al (August 2008). "Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy". CMAJ 179 (5): 417–26. DOI:10.1503/cmaj.080493. PMID 18725614. PMC 2518177. Research Blogging.

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