Venous thrombosis

Venous thrombosis
Classification and external resources

A deep vein thrombosis in the right leg. Note the swelling and redness.
ICD-10 I80-I82
ICD-9 453
MeSH D020246

A venous thrombosis is a blood clot (thrombus) that forms within a vein. Thrombosis is a medical term for a blood clot occurring in the wrong place, such as inside a blood vessel. A venuos thromboembolism is a specific type of venous thrombosis and a term refers to the serious conditions of deep vein thrombosis and pulmonary embolism.[1]

Contents

Classification

Superficial venous thromboses can cause discomfort but generally do not cause serious consequences, unlike the deep venous thromboses (DVTs) that form in the deep veins of the legs or in the pelvic veins.

Since the veins return blood to the heart, if a piece of a blood clot formed in a vein breaks off it can be transported to the right side of the heart, and from there into the lungs. A piece of thrombus that is transported in this way is an embolism: the process of forming a thrombus that becomes embolic is called a thromboembolism. An embolism that lodges in the lungs is a pulmonary embolism (PE). A pulmonary embolus is a very serious condition that can be fatal if not recognized and treated promptly. Venous thromboembolism refers to both DVTs and PEs.

Systemic embolisms of venous origin can occur in patients with an atrial or ventricular septal defect, through which an embolus may pass into the arterial system. Such an event is termed a paradoxical embolism.

Risk factors

Further information: Hypercoagulability

Prevention

Prophylaxis of venous thromboembolism with heparin in medical patients does not appear to decrease mortality and while it may decrease the risk of pulmonary embolism and deep vein thrombosis it increases the risk of bleeding and thus results in little or no overall clinical benefit.[5][6] Mechanical measures also appeared of little benefit in this group and in those with a strokeresulted in harm.[5] Evidence supports the use of heparin following surgery which has a high risk of thrombosis to reduce the risk of DVTs; however the effect on PEs or overall mortality is not known.[7][8][9]

Treatment

Evidence-based guidelines have been published for the treatment of venous thromboembolism.[10] Medications used to treat this condition include anticoagulants such as heparin, fondaparinux and more recently dabigatran has shown promise.[11] Vitamin K antagonists such as warfarin are also commonly used.

See also

References

  1. ^ Qaseem A, Chou R, Humphrey LL, Starkey M, Shekelle P, Clinical Guidelines Committee of the American College of Physicians (2011). "Venous thromboembolism prophylaxis in hospitalized patients: a clinical practice guideline from the American College of Physicians". Ann Intern Med 155 (9): 625-32. doi:10.1059/0003-4819-155-9-201111010-00011. PMID 22041951. http://www.annals.org/content/155/9/625.long. 
  2. ^ van Stralen KJ, Rosendaal FR, Doggen CJ (2008). "Minor injuries as a risk factor for venous thrombosis". Arch Intern Med 168 (1): 21-6. doi:10.1001/archinternmed.2007.5. PMID 18195191. http://archinte.ama-assn.org/cgi/content/short/168/1/21. 
  3. ^ Sukal S, Geronemus R. "Deep Venous Thrombosis Following Mohs Micrographic Surgery: A Case Report" Dermatol Surg. 34(3):414-417. 2008
  4. ^ Stein PD, Beemath A, Meyers FA, Skaf E, Sanchez J, Olson RE (2006). "Incidence of venous thromboembolism in patients hospitalized with cancer". Am J Med 119 (1): 60-8. doi:10.1016/j.amjmed.2005.06.058. PMID 16431186. 
  5. ^ a b Lederle, FA; Zylla, D, Macdonald, R, Wilt, TJ (2011 Nov 1). "Venous thromboembolism prophylaxis in hospitalized medical patients and those with stroke: a background review for an american college of physicians clinical practice guideline.". Annals of internal medicine 155 (9): 602-15. PMID 22041949. 
  6. ^ Alikhan, R; Cohen, AT (2009 Jul 8). "Heparin for the prevention of venous thromboembolism in general medical patients (excluding stroke and myocardial infarction).". Cochrane database of systematic reviews (Online) (3): CD003747. PMID 19588346. 
  7. ^ Oates-Whitehead, RM; D'Angelo, A, Mol, B (2003). "Anticoagulant and aspirin prophylaxis for preventing thromboembolism after major gynaecological surgery.". Cochrane database of systematic reviews (Online) (4): CD003679. PMID 14583989. 
  8. ^ Handoll, HH; Farrar, MJ, McBirnie, J, Tytherleigh-Strong, G, Milne, AA, Gillespie, WJ (2002). "Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures.". Cochrane database of systematic reviews (Online) (4): CD000305. PMID 12519540. 
  9. ^ Roderick, P; Ferris, G, Wilson, K, Halls, H, Jackson, D, Collins, R, Baigent, C (2005 Dec). "Towards evidence-based guidelines for the prevention of venous thromboembolism: systematic reviews of mechanical methods, oral anticoagulation, dextran and regional anaesthesia as thromboprophylaxis.". Health technology assessment (Winchester, England) 9 (49): iii-iv, ix-x, 1-78. PMID 16336844. 
  10. ^ Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR, Colwell CW; American College of Chest Physicians (2008). "Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)". Chest 133 (6): 381S–453S. doi:10.1378/chest.08-0656. PMID 18574271. http://hinari-gw.who.int/whalecomchestjournal.chestpubs.org/whalecom0/content/133/6_suppl/381S.long. 
  11. ^ Schulman S, Kearon C, Kakkar AK, et al (2009). "Dabigatran versus warfarin in the treatment of acute venous thromboembolism". N Engl J Med 361 (24): 2342–52. doi:10.1056/NEJMoa0906598. PMID 19966341. http://content.nejm.org/cgi/content/abstract/NEJMoa0906598v1. 

External links