Ultrasound screening
Compression ultrasound looking for evidence of acute DVT is an excellent screening test in high-risk patients, such as patients who have sustained major trauma and patients who have recently undergone total hip or knee replacement. There is no convincing evidence, however, that screening reduces the incidence of adverse outcomes, particularly the incidence of fatal pulmonary embolism. The overall accuracy of screening ultrasound in asymptomatic patients is not clear but it is lower than in symptomatic patients.[100]Segal JB, Eng J, Tamariz LJ, et al. Review of the evidence on diagnosis of deep venous thrombosis and pulmonary embolism. Ann Fam Med. 2007 Jan-Feb;5(1):63-73.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1783914
http://www.ncbi.nlm.nih.gov/pubmed/17261866?tool=bestpractice.com
Less than half of patients who develop pulmonary embolism have ultrasound evidence of DVT in the legs; therefore, the value of detecting asymptomatic DVT in preventing pulmonary embolism is uncertain. Guidelines conflict regarding whether screening ultrasound should be performed in hospitalised trauma patients.[101]Haut ER, Schneider EB, Patel A, et al. Duplex ultrasound screening for deep vein thrombosis in asymptomatic trauma patients: a survey of individual trauma surgeon opinions and current trauma center practices. J Trauma. 2011 Jan;70(1):27-33.
http://www.ncbi.nlm.nih.gov/pubmed/21217477?tool=bestpractice.com
[102]Gould MK, Garcia DA, Wren SM, et al. Prevention of VTE in nonorthopedic surgical patients: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2012 Feb;141(2 Suppl):e227S-77S.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3278061
http://www.ncbi.nlm.nih.gov/pubmed/22315263?tool=bestpractice.com
Thrombophilia screening
Consider testing for hereditary thrombophilia in patients who don't have an identifiable risk factor and have a first-degree relative who has had a VTE, if it is planned to stop anticoagulation.[12]National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. Aug 2023 [internet publication].
https://www.nice.org.uk/guidance/ng158
[26]Kakkos SK, Gohel M, Baekgaard N, et al. Editor's choice: European Society for Vascular Surgery (ESVS) 2021 clinical practice guidelines on the management of venous thrombosis. Eur J Vasc Endovasc Surg. 2021 Jan;61(1):9-82.
https://www.ejves.com/article/S1078-5884(20)30868-6/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/33334670?tool=bestpractice.com
Do not routinely offer thrombophilia testing to first-degree relatives of people with a history of DVT and thrombophilia.[12]National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. Aug 2023 [internet publication].
https://www.nice.org.uk/guidance/ng158
Consider testing for antiphospholipid antibodies in patients who have had an unprovoked DVT if it is planned to stop anticoagulation treatment.[12]National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. Aug 2023 [internet publication].
https://www.nice.org.uk/guidance/ng158
[26]Kakkos SK, Gohel M, Baekgaard N, et al. Editor's choice: European Society for Vascular Surgery (ESVS) 2021 clinical practice guidelines on the management of venous thrombosis. Eur J Vasc Endovasc Surg. 2021 Jan;61(1):9-82.
https://www.ejves.com/article/S1078-5884(20)30868-6/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/33334670?tool=bestpractice.com
In practice, this is usually only done if the patient is young (aged <50 years).
Be aware that tests for hereditary thrombophilia and antiphospholipid antibodies can be affected by anticoagulation; specialist advice may be needed.[12]National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. Aug 2023 [internet publication].
https://www.nice.org.uk/guidance/ng158
Cancer screening
In any patient diagnosed with unprovoked DVT who is not known to have cancer:[12]National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. Aug 2023 [internet publication].
https://www.nice.org.uk/guidance/ng158
Review medical history
Review baseline blood tests including full blood count, renal and hepatic function, prothrombin time (PT), and activated partial thromboplastin time (aPTT)
Offer a physical examination.[26]Kakkos SK, Gohel M, Baekgaard N, et al. Editor's choice: European Society for Vascular Surgery (ESVS) 2021 clinical practice guidelines on the management of venous thrombosis. Eur J Vasc Endovasc Surg. 2021 Jan;61(1):9-82.
https://www.ejves.com/article/S1078-5884(20)30868-6/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/33334670?tool=bestpractice.com
Do not offer further investigations for cancer for patients with an unprovoked DVT unless they have relevant clinical symptoms or signs.[12]National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. Aug 2023 [internet publication].
https://www.nice.org.uk/guidance/ng158
Occult cancer is present in approximately 3% to 5% of patients with an unprovoked DVT.[93]Timp JF, Braekkan SK, Versteeg HH, et al. Epidemiology of cancer-associated venous thrombosis. Blood. 2013 Sep 5;122(10):1712-23.
http://www.bloodjournal.org/content/122/10/1712.long
http://www.ncbi.nlm.nih.gov/pubmed/23908465?tool=bestpractice.com
These recommendations are based on the National Institute for Health and Care Excellence in the UK. However, note that the European Society for Vascular Surgery recommends clinical examination and sex-specific cancer screening (but without routine extensive screening for cancer) if the patient has an unprovoked DVT.[26]Kakkos SK, Gohel M, Baekgaard N, et al. Editor's choice: European Society for Vascular Surgery (ESVS) 2021 clinical practice guidelines on the management of venous thrombosis. Eur J Vasc Endovasc Surg. 2021 Jan;61(1):9-82.
https://www.ejves.com/article/S1078-5884(20)30868-6/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/33334670?tool=bestpractice.com