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Latest revision as of 03:32, 20 May 2014
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vidit Bhargava, M.B.B.S [2]; Rim Halaby, M.D. [3]
Overview
Deep vein thrombosis (DVT) is the formation of a blood clot ("thrombus") in a deep vein.
Causes
Life Threatening Causes
Deep venous thrombosis can be a life-threatening condition if thromboembolism and subsequent pulmonary embolism occur, and it must be treated as such irrespective of the underlying cause.
Common Causes
FIRE: Focused Initial Rapid Evaluation
A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.
Complete Diagnostic Approach for First Episode of DVT
Shown below are the different diagnostic approaches to the diagnosis of DVT depending on the pre-test probability of the disease.[1]
Low Pretest Probability
| The patient has a low pre-test probability for DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with one of the following: Highly or moderately sensitive D-dimer test (1st line) Proximal US (2nd line) Whole leg US (less preferred) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| D-dimer (1st line) | Proximal US (2nd line) | Whole leg US (less preferred) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with either: Proximal US (1st line) OR Whole leg US (less preferred) | What is the location of the DVT? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Proximal US (1st line) | Whole leg US (less preferred) | DVT is excluded | Treat DVT | DVT is excluded | Proximal DVT | Isolated distal DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Treat DVT | Perform serial US (1st line) OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| What is the location of the DVT? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat DVT | DVT is excluded | Proximal DVT | Isolated distal DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Treat DVT | Perform serial US (1st line) OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moderate Pretest Probability
| The patient has a moderate pre-test probability of DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with one of the following: D-dimer test | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highly sensitive D-dimer test | Proximal US | Whole leg US | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with either: Proximal US OR Whole leg US | Repeat proximal US OR Moderately/highly sensitive D-dimer | Treat DVT | DVT is excluded | Where is the location of the DVT? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Proximal US | Whole leg US | Repeat proximal US within 1 week | Moderately/highly sensitive D-dimer | Proximal DVT | Isolated distal DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | Negative | Positive | Treat DVT | Perform serial US (1st line) OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Repeat proximal US within 1 week | Treat DVT | DVT is excluded | What is the location of the DVT? | DVT is excluded | Treat DVT | DVT is excluded | Repeat proximal US within 1 week | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Proximal DVT | Isolated distal DVT | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat DVT | Treat DVT | Perform serial US (1st line) OR Treat DVT | Treat DVT | Perform serial US (1st line) OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
High Pretest Probability
| The patient has a high pre-test probability for DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with either: Proximal US OR Whole leg US | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proximal US | Whole leg US | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with ONE of the following: Repeat proximal US Highly sensitive D-dimer Whole leg US Venography (less preferred) | Treat DVT | DVT is excluded | What is the location of the DVT? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proximal | Distal | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Treat DVT | Perform serial US (1st line) OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Repeat proximal US within 1 week | Highly sensitive D-dimer | Whole leg US | Venography | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat DVT | DVT is excluded | DVT is excluded | Where is the location of the DVT? | DVT is excluded | Treat DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Repeat proximal US within 1 week | Whole leg US | Venography (less preferred) | Proximal | Distal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | Treat DVT | Perform serial US (1st line) OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat DVT | DVT is excluded | Where is the location of the DVT? | DVT is excluded | Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proximal | Distal | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Treat DVT | Perform serial US (1st line) OR Treat DVT | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Complete Diagnostic Approach for Recurrent DVT
Shown below is the diagnostic approach to suspected recurrent DVT. The recommended initial test is either proximal ultrasound (US) or highly sensitive D-dimer tetsing rather than venography, CT venography or MR imagining. Initial D-dimer testing is recommended over proximal US in case there is no prior ultrasound for comparison. Note the following definitions:
- Negative US:
- Normal US, or
- Increase in residual diameter of less than 2 mman, or
- Area of prior noncompressibility with a decreased or stable residual diameter
- Nondiagnostic US:
- Ultrasound that is technically limited, or
- Area of prior noncompressibility with an increment in residual venous diameter of < 4 mm yet ≥ 2 mm, or
- Area of prior noncompressibility in the absence of a previous measurement of the residual diameter
- Positive US:
- New noncompressible segment, or
- Area of prior noncompressibility with an increment in residual venous diameter of ≥ 4 mm
| The patient has recurrent DVT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with one of the following: Proximal US Moderately/highly sensitive D-dimer Venography (less preferred) CT venography (less preferred) MR imaging (less preferred) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proximal US | Moderately/highly sensitive D-dimer | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Non diagnostic | Positive | Negative | Positive | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with one of the following: D-dimer Repeat proximal US within 1 week Venography (less preferred) No further testing (less preferred) | Click here for the diagnostic approach in case of inconclusive US | Treat OR Venography (less preferred) | DVT is excluded | Proximal US | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Moderately/highly sensitive D-dimer | Repeat US | Venography | No further testing | Negative | Non diagnostic | Positive | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | Repeat proximal US within 1 week OR Venography (less preferred) OR No further testing (less preferred) | Click here for the diagnostic approach in case of inconclusive US | Treat OR Venography (less preferred) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Repeat proximal US within 1 week OR Venography (less preferred) OR No further testing (less preferred) | DVT is excluded | Treat OR Venography (less preferred) | DVT is excluded | Treat DVT | If proximal US is repeated, what is the result? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| If proximal US is repeated, what is the result? | Negative | Positive | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | DVT is excluded | Treat OR Venography (less preferred) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat OR Venography (less preferred) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Diagnostic Approach for Non Diagnostic Ultrasound
| The patient has a non diagnostic proximal US | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Are prior US results available? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Yes | No | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Proceed with ONE of the following: Venography (most preferred) Repeat proximal US within 1 week Highly/moderately sensitive D-dimer Treat DVT (less preferred) | Proceed with ONE of the following: Venography (most preferred) Highly sensitive D-dimer Repeat proximal US (less preferred) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Venography (most preferred) | Repeat proximal US within 1 week | Highly/moderately sensitive D-dimer | Treat DVT (less preferred) | Venography (most preferred) | Highly sensitive D-dimer | Repeat proximal US within 1 week | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | Negative | Positive | Negative | Positive | Negative | Positive | Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Treat DVT | DVT is excluded | Treat DVT OR Venography (less preferred) | DVT is excluded | Repeat proximal US within 1 week | DVT is excluded | Treat DVT | DVT is excluded | Venography OR Treat DVT (less preferred) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DVT is excluded | Venography (less preferred) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Diagnostic Approach for Venography
| What is the result of the venography? | |||||||||||||||||
| Negative | Positive | ||||||||||||||||
| DVT is excluded | Treat DVT | ||||||||||||||||
Long Term Treatment
Shown below is the long term treatment for DVT. Note that not all patients with isolated distal DVT are started on anticoagulation, only those who are started require long term therapy with anticoagulation. Patients who are planned to receive long term therapy with anticoagulation should be assessed regularly for the risks vs benefits of anticoagulation therapy.[2]
| Is the DVT provoked or unprovoked? | |||||||||||||||||||||||||||||||||||||||||||
| Provoked | Unprovoked | ||||||||||||||||||||||||||||||||||||||||||
| What is the predisposing factor? | Is this the first or second episode? | ||||||||||||||||||||||||||||||||||||||||||
| Surgical OR <bt>Transient non surgical predisposing factor | Cancer | First episode | Second episode | ||||||||||||||||||||||||||||||||||||||||
| Anticoagulation therapy for 3 months | Extended anticoagulation therapy | Is the DVT proximal or distal? | What is the risk of bleeding? | ||||||||||||||||||||||||||||||||||||||||
| Proximal DVT | Isolated distal DVT | Low or moderate risk of bleeding | High risk of bleeding | ||||||||||||||||||||||||||||||||||||||||
| What is the risk of bleeding? | Anticoagulation therapy for 3 months (irrespective of the risk of bleeding) | Extended anticoagulation therapy | Anticoagulation therapy for 3 months | ||||||||||||||||||||||||||||||||||||||||
| Low or moderate | High | ||||||||||||||||||||||||||||||||||||||||||
| Extended anticoagulation therapy | Anticoagulation therapy for 3 months | ||||||||||||||||||||||||||||||||||||||||||
Assessment of Risk of Bleeding
The risk factors of bleeding with anticoagulation therapy are:[3]
- Age > 75 years
- Alcohol abuse
- Anemia
- Antiplatelet therapy
- Cancer
- Comorbidity and reduced functional capacity
- Diabetes
- Frequent falls
- Liver failure
- Metastatic cancer
- Poor anticoagulant control
- Previous bleeding
- Prior stroke
- Recent surgery
- Renal failure
- Thrombocytopenia
Shown below is a table summarizing the risk of bleed based on the number of risk factors. Note that, although the presence of one risk factor signify moderate risk of bleeding, if the single risk factor is severe (such as severe thrombocytopenia or recent major surgery) then the patient is at high risk of bleeding despite the presence of a single risk factor.
| Risk of bleeding | Number of risk factors[3] |
| Low Risk | 0 |
| Moderate Risk | 1 |
| High Risk | ≥2 |
Do's
- Among patients with low pretest probability of DVT, the preferred initial test is D-dimer. However, among those patients who have comorbidities known to increase D-dimer concentration in the absence of a venous thromboembolism, ultrasound is preferred as an initial test.
- Patients with low pretest probability of DVT among whom an ultrasound can not be practically performed, for example due to the presence of a leg cast, or those who have non-diagnostic ultrasound results, CT scan venography, magnetic resonance venography, or magnetic resonance direct thrombus imaging can be considered instead of venography.
- Among patients with moderate pretest probability of DVT, whole leg US might be preferred over proximal US in case there is severe symptoms consistent with calf pain or in case the patients have difficulty returning for the serial US tests. Patients among whom an ultrasound can not be practically performed, for example due to the presence of a leg cast, or those who have non-diagnostic ultrasound results, CT scan venography, magnetic resonance venography, or magnetic resonance direct thrombus imaging can be considered instead of venography.
- Among patients who underwent whole leg ultrasound that revealed isolated distal DVT, consider serial US testing over trearment to check for extension of the thrombus. However, if the pretest probability is high or there is elevated risk of extension or severe symptoms, consider treatment over serial US testing.
Don'ts
References
- ↑ Bates SM, Jaeschke R, Stevens SM, Goodacre S, Wells PS, Stevenson MD; et al. (2012). "Diagnosis of DVT: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): e351S–418S. doi:10.1378/chest.11-2299. PMC 3278048. PMID 22315267.
- ↑ Guyatt GH, Akl EA, Crowther M, Gutterman DD, Schuünemann HJ, American College of Chest Physicians Antithrombotic Therapy and Prevention of Thrombosis Panel (2012). "Executive summary: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): 7S–47S. doi:10.1378/chest.1412S3. PMC 3278060. PMID 22315257.
- ↑ 3.0 3.1 Kearon C, Akl EA, Comerota AJ, Prandoni P, Bounameaux H, Goldhaber SZ; et al. (2012). "Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines". Chest. 141 (2 Suppl): e419S–94S. doi:10.1378/chest.11-2301. PMC 3278049. PMID 22315268.