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Three Part Question

In [a patient with suspected DVT], can [compression US] [confirm the diagnosis]?

Clinical Scenario

A 52 yr old man presents with painful swollen right leg. On examination, he has moderate risk on wells score for DVT. Blood tests show a Raised D-Dimer. You wonder if compression Ultrasound has suffiently accurate in ruling in or ruling out the diagnosis of deep vein thrombosis.

Search Strategy

Database: Dialog Datastar 1950 to January 2008

Search Outcome

55 papers were found of which 6 were related directly to the question asked

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Hay, 1991, Welkom, OFS	CUS was performed in 63 legs (61 patients) using linear transducer and results compared to contrast venography in femoropopliteal veins	Prospective	16/51 (31%) had femoropopliteal DVT on CUS & contrast venography. 32/51 (63%) were normal. 3 (6%) were false negatives. 9/63 (14%) had indeterminate CUS examination and were excluded.	Sensitivity of CUS for femoropopliteal veins was 84%, specificity 100%, accuracy 94%, positive predictive value 100%, negative predictive value 91%.	Only one radiologist was doing procedure who was not blinded to results. No randomisation was done.pulsed Doppler USG was not available. calf DVT’s were not checked and positive calf DVT’s on contrast venography was taken as normal
Jongbloets et al, 1994, Netherlands	100 patients had compression ultrasound and contrast venography to detect proximal and isolated calf DVT in symptom free patients who had undergone craniotomy	Observational	Ultrasonography was done immediately before venography on the 7th to 9th postoperative day. Incomplete vein compression was the only criterion for the presence of DVT. Bilateral ascending contrast venography was done without ankle tourniquets.	For proximal vein thrombosis, USG was 38% sensitive, 95% specific and had positive predictive value of 56%. For calf vein thrombosis, USG was 50% sensitive, 73% specific and had positive predictive value of 35%. Overall USG had sensitivity of 50% and had positive predictive value of 41%. Most thrombi missed by USG were non-occlusive and smaller then 5 cm	All post-operative symptom less patients included in study.
Robinson et al, 1998, Canada	86 patients included (41 had THR & 45 had TKR) to determine whether compression ultrasonography or clinical examination should be considered a screening test to assess DVT after THR and TKR	Prospective Cohort	Patients were assessed for DVT by clinical examination, compression USG and contrast venography	34% of patients had venographic evidence of DVT Sensitivity of compression USG was 83 % and specificity was 98%. Positive predictive value was 71%. Sensitivity of clinical examination was 11%. Positive predictive value was 25%.	Small no of patients, Low sensitivity of clinical examination, sensitivity of compression USG depends on size of proximal DVT
Birdwell et al, 2000, USA	709 patients were included to evaluate the positive predictive value of compression USG according to the anatomic site of noncompressibility	Prospective cohort study	Compression USG was considered abnormal if noncompressable segment was identified. Venography was performed on patients with abnormal compression results. Positive predictive value was determined according to site of noncompressibility: femoral vein, popliteal vein or both.	Positive predictive value was 16.7%for noncompressibility isolated to the common femoral vein compared with 91.3% for the popliteal vein only and 94.4% for both sites. Of 15 patients with isolated noncompressibility of common femoral vein, 8(53%) had pelvic neoplasm or abscess compared with 2(5%) of 42 with noncompressibility of the popliteal vein only and 6(13%) of 47 with noncompressibility of both sides.	Doppler flow or colour flow imaging was not used
Tick et al, 2002, Netherlands	811 patients with clinically suspected DVT were studied using a diagnostic management strategy that combined clinical probability (Wells criteria), CUS (linear array) and D-Dimer measurements.All were followed for 3 months to assess for development of DVT.	Prospective cohort	Of the 280 patients (35%) with a low clinical probability, 30 (11%) had an abnormal initial ultrasonography and were treated. Of the other 250 untreated patients with low clinical probability and a normal ultrasonography, 5 (2%; 95% confidence interval [CI]: 1% to 5%) developed a nonfatal venous thromboembolism during follow-up. Of the 531 patients (65%) with a moderate-to-high clinical probability, 300 (56%) had an abnormal ultrasonography. Of the remaining 231 patients with a normal ultrasonography, 148 had a normal D-dimer test; none of these patients developed deep vein thrombosis during follow-up (0%; 95% CI: 0% to 3%). Of the 83 patients with an abnormal D-dimer test, 77 underwent repeat ultrasonography about 1 week later; none of the 64 patients with a second normal ultrasound developed symptomatic deep vein thrombosis during follow-up (0%; 95% CI: 0% to 6%).	This management strategy, which combines clinical probability, ultrasonography, and D-dimer measurements, reduces the need for repeat ultrasonography by 83%.	No standard used. Calf vein DVT not assessed. Longitudinal scanning not done
Jang et al, 2004, USA	8 Emergency residents performed CUS to detect proximal lower extremity DVT enrolling 72 patients	Prospective Observational	Detection of proximal lower extremity DVT with compression ultrasonography confirmed by CT venography or Duplex USG. Average time scan was 11.7 min.	23 true positives, 4 false positives, 45 true negatives, 0 false negatives, 100% sensitivity, 91.8% specificity	Consistent standard not used CT venography & venous duplex USG used to confirm DVT, selection bias, only 8 out of 48 residents participated. Calf DVT not included

Comment(s)

Compression USG is a non-invasive test which is useful in detecting DVT in symptomatic patients. It requires minimal training and can be done in Emergency Department. It is not useful in symptom free high risk patients and has a sensitivity of 83 – 100% and specificity of 91 – 100 %. Clinical Examination alone has a low sensitivity.

Clinical Bottom Line

Compression US is a reliable diagnostic tool in symptomatic patients and has a high sensitivity and specificity.

References

1. Hay M. Real-time sector compression ultrasonography v. contrast venography in femoropopliteal thrombosis. S Afr Med J. 1991 Dec 7;80(11-12):570-2.
2. Jongbloets LM, Lensing AW, Koopman MM, Büller HR, ten Cate JW. Limitations of compression ultrasound for the detection of symptomless postoperative deep vein thrombosis. Lancet. 1994 May 7;343(8906):1142-4.
3. Robinson KS, Anderson DR, Gross M, Petrie D, Leighton R, Stanish W, Alexander D, Mitchell M, Mason W, Flemming B, Fairhurst-Vaughan M, Gent M. Accuracy of screening compression ultrasonography and clinical examination for the diagnosis of deep vein thrombosis after total hip or knee arthroplasty. Can J Surg. 1998 Oct;41(5):368-73.
4. Birdwell BG, Raskob GE, Whitsett TL, Durica SS, Comp PC, George JN, Tytle TL, Owen WL, McKee PA. Predictive value of compression ultrasonography for deep vein thrombosis in symptomatic outpatients: clinical implications of the site of vein noncompressibility. Arch Intern Med. 2000 Feb 14;160(3):309-13.
5. Tick LW, Ton E, van Voorthuizen T, Hovens MM, Leeuwenburgh I, Lobatto S, Stijnen PJ, van der Heul C, Huisman PM, Kramer MH, Huisman MV. Practical diagnostic management of patients with clinically suspected deep vein thrombosis by clinical probability test, compression ultrasonography, and D-dimer test. Am J Med. 2002 Dec 1;113(8):630-5.
6. Jang T, Docherty M, Aubin C, Polites G. Resident-performed compression ultrasonography for the detection of proximal deep vein thrombosis: fast and accurate. Acad Emerg Med. 2004 Mar;11(3):319-22.