Antithrombotic treatment of below knee deep venous thrombosis
- Kerstin Hogg, Clinical Research Fellow,
- Andrew Ashton, Senior Clinical Fellow
- Department of Emergency Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK; kevin.mackway-jones:man.ac.uk
Abstract
A short cut review was carried out to establish whether oral anticoagulation is necessary to prevent pulmonary embolisation in patients with below knee deep venous thrombosis. A total of 425 papers were found using the reported search, of which 11 presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. A clinical bottom line is stated.
Report by Kerstin Hogg,Clinical Research Fellow Checked by Andrew Ashton, Senior Clinical Fellow
Clinical scenario
A 50 year old man attends the emergency department with a plethoric, swollen left calf. Ultrasound examination reveals a posterior tibial vein thrombosis. You wonder what the risk of a pulmonary embolus is and whether he should be anticoagulated.
Three part question
In [a patient with a below knee venous thrombosis], is [oral anticoagulation necessary] to prevent [a pulmonary embolus]?
Search strategy
Medline 1966–04/03 using the OVID interface. [{(DVT.mp OR exp venous thrombosis OR “deep vein thrombosis”.mp) AND (“below knee”.mp OR calf.mp OR popliteal.mp OR exp popliteal vein OR fibular.mp OR peroneal.mp OR posterior tibial.mp) OR “deep calf venous thrombosis”.mp OR “calf vein thrombi”.mp}AND (therapy.mp OR exp therapeutics OR treatment.mp OR exp heparin OR exp heparin, low-molecular-weight OR heparin.mp OR exp warfarin OR warfarin.mp OR exp coumarins OR coumarin.mp)] LIMIT to human and English.
Search outcome
Altogether 425 papers were found, only 10 original papers and one literature review addressed the question. Some studies included other patients with PE or thigh DVTs—only the patients with calf thrombosis are described (table 3).
Comment(s)
All of these studies could have been more thorough in their diagnostic criteria and/or follow up. However, despite the flaws it is clear that pulmonary emboli do result from below knee thrombi.
CLINICAL BOTTOM LINE
All patients with calf thrombosis should receive oral anticoagulation.
Report by Kerstin Hogg,Clinical Research Fellow Checked by Andrew Ashton, Senior Clinical Fellow
