116 – What are the indications for Doppler ultrasound of the lower extremity to confirm or rule out DVT?

116 – What are the indications for Doppler ultrasound of the lower extremity to confirm or rule out DVT?

Geno Merli, Michael Tanzer, Nicola Gallagher, David Beverland.

Response/Recommendation:  In the absence of any specific guidance from the literature we would propose that in any patient who is within 6 weeks following a lower limb surgery that a Doppler scan should be requested when:

a.   There is lower limb swelling that does not respond to elevation or after a night’s rest in bed.

b.   The lower extremity swelling worsens after a night spent recumbent.

c.   There is a high index of suspicion for deep venous thrombosis (DVT) in patients with active cancer and/or history of prior venous thromboembolism (VTE).

Strength of Recommendation: Limited.

Rationale: Having assessed the literature the presently available tools, such as the Well’s score[1], are based predominantly on assessing the indications for Doppler in the situation of an unprovoked DVT.  When using such scores, the majority of postoperative total joint arthroplasty (TJA) meet the criteria for a Doppler investigation and therefore such scores are unsuitable for this patient population.

There are no studies specifically assessing the indications for Doppler ultrasound in determining the presence of a DVT following TJA.  In addition, there are no studies that have determined the positive or negative predictive value of clinical criteria used to trigger the use of a Doppler ultrasound to determine if a DVT has developed following TJA.

DVT occurring after lower limb TJA appears to follow a different and more benign pathway than unprovoked DVT[2,3], which has significantly reported morbidity and mortality.  Postoperative DVT is largely asymptomatic with the reported incidence often being about 10% when every postoperative TJA has a Doppler[4].  The presence of DVT has not been shown to correlate with age, gender, race, presence of diabetes mellitus, history of malignancy, smoking status, fixation type, primary versus revision type of surgery, or operating time[5].  Although a symptomatic DVT may occur in the hospital, the assessment and diagnosis is more commonly an issue for patients who have been discharged and then present to the emergency room with lower limb pain and or swelling.

To highlight the present uncertainty about the indications for a Doppler scan following TJA, a study using data from Musgrave Park hospital in Belfast, Northern Ireland looked at over 10,000 TJAs performed since 2016. This yet unpublished study found that over 8% of patients had at least one Doppler after TJA with <5% having a proximal DVT.  According to the British National Institute for Health and Care Excellence (NICE) guidelines[6], if a Doppler scan cannot be done within 4 hours of being requested then the patient should receive therapeutic anticoagulation.  As a result, many of the patients with a negative scan received therapeutic anticoagulation.  Furthermore, if the scan is negative then NICE recommends a further scan in the following 6 to 8 days[6].  As a result, many patients had a second Doppler.

The two major concerns about missing a DVT are propagation to the lung with a subsequent pulmonary embolism (PE) and risk of death and post-thrombotic syndrome.  With regard to the first concern, we are not aware of any literature that has demonstrated that propagation of a DVT to the lung occurs following TJA.  With regard to the post-thrombotic syndrome, this is clearly an important clinical issue with a reported incidence of between 20% and 50% following DVT[7] but again this would appear to be following unprovoked DVT with no published evidence about DVT as a consequence of TJA.  It is generally considered that a venous clot will recanalize within 3 months and that this process is not aided by anticoagulation with the latter simply preventing extension locally or to the lung.

The rationale of focusing attention on postoperative swelling that doesn’t respond to elevation is that these are the patients who are perhaps at higher risk from developing a post-thrombotic syndrome and who may therefore benefit from anticoagulation to reduce the risk of local extension.

In the general population, it has been shown that when leg edema or calf tenderness was present, the incidence of acute DVT was significantly greater (p < 0.0001)[8].  Although these may be common symptoms after TJA, it is not unreasonable to consider that increased or sudden unilateral swelling after elevation or first thing in the morning after awakening may indicate the need for a Doppler ultrasound[9].  We recommend that once the scan has been ordered the patient should not normally be anticoagulated prior to a positive scan result unless the scan cannot be done for more than 24 hours.  If the patient is on routine VTE prophylaxis this should continue as prescribed.  If there is a distal or calf DVT, then the patient does not need to be anticoagulated, and the scan does not need to be repeated unless there is a further change in the symptoms.  If the scan is negative, it does not need to be routinely repeated unless there is a further change in symptoms.  If the patient has a proximal DVT, then the patient should be anticoagulated according to local protocols.  Throughout this process and regardless of the diagnosis, the patient should continue with their normal rehabilitation program.  If the investigations have not been ordered by the surgical team, they should be informed independently of the outcome.


[1]        Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J, et al. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. N Engl J Med 2003;349:1227–35. https://doi.org/10.1056/NEJMoa023153.

[2]        Lutsey PL, Virnig BA, Durham SB, Steffen LM, Hirsch AT, Jacobs DR, et al. Correlates and consequences of venous thromboembolism: The Iowa Women’s Health Study. Am J Public Health 2010;100:1506–13. https://doi.org/10.2105/AJPH.2008.157776.

[3]        Heit JA, Spencer FA, White RH. The epidemiology of venous thromboembolism. J Thromb Thrombolysis 2016;41:3–14. https://doi.org/10.1007/s11239-015-1311-6.

[4]        Song K, Xu Z, Rong Z, Yang X, Yao Y, Shen Y, et al. The incidence of venous thromboembolism following total knee arthroplasty: a prospective study by using computed tomographic pulmonary angiography in combination with bilateral lower limb venography. Blood Coagul Fibrinolysis 2016;27:266–9. https://doi.org/10.1097/MBC.0000000000000408.

[5]        Wong KL, Daguman R, Lim KH, Shen L, Lingaraj K. Incidence of deep vein thrombosis following total hip arthroplasty: a Doppler ultrasonographic study. J Orthop Surg (Hong Kong) 2011;19:50–3. https://doi.org/10.1177/230949901101900111.

[6]        Venous thromboembolic diseases: diagnosis, management and thrombophilia testing n.d.:47.

[7]        Kahn SR. The post-thrombotic syndrome. Hematology Am Soc Hematol Educ Program 2016;2016:413–8. https://doi.org/10.1182/asheducation-2016.1.413.

[8]        Fowl RJ, Strothman GB, Blebea J, Rosenthal GJ, Kempczinski RF. Inappropriate use of venous duplex scans: an analysis of indications and results. J Vasc Surg 1996;23:881–5; discussion 885-886. https://doi.org/10.1016/s0741-5214(96)70251-3.

[9]        Glover JL, Bendick PJ. Appropriate indications for venous duplex ultrasonographic examinations. Surgery 1996;120:725–30; discussion 730-731. https://doi.org/10.1016/s0039-6060(96)80023-7.

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