Association between asymptomatic deep-vein thrombosis detected by venography and symptomatic venous thromboembolism in patients undergoing elective hip or knee surgery

• Background: Venography is commonly used to compare the efficacy of different thromboprophylaxis strategies for preventing deep-vein thrombosis (DVT) in patients undergoing total hip replacement (THR) or total knee replacement (TKR). Methods: We explored the relation between asymptomatic DVT and symptomatic VTE in patients undergoing THR or TKR treated with standard doses of enoxaparin (30 mg b.i.d. or 40 mg o.d.) by comparing the prevalence of asymptomatic DVT in venographic studies with the incidence of symptomatic VTE in studies where venography was not performed. Results: In 10 venographic studies involving 5,796 patients, the prevalence of asymptomatic DVT after THR was 13.2% (95%CI, 12.2%-14.2%) and after TKR was 38.1% (95%CI, 35.5%-40.8%). In two studies involving 3,500 patients who did not undergo venography, the 90-day incidence of symptomatic VTE after THR was 2.7% (95%CI, 2.1%-3.4%) and after TKR was 1.8% (95%CI, 0.9%-2.7%). For every symptomatic VTE in THR studies where venography was not performed there were 5 asymptomatic DVTs in the venographic studies; for TKR, the ratio was 1:21. The prevalence of asymptomatic DVT and the symptomatic VTE/asymptomatic DVT ratio was influenced by the venogram reading committee (Gothenburg vs. Hamilton - total DVT after THR: 19.5% vs. 8.7%, p < 0.0001; for TKR: 42.7% vs. 27.2%, p < 0.0001). Conclusions: Comparisons across trials show a consistent relation between asymptomatic venographic DVT in patients undergoing elective THR or TKR surgery and symptomatic VTE in patients not undergoing venography. Differences exist in the strength of the relation depending on the type of surgery and the venogram reading committee.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Kirurgi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Surgery (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)