Distribution of acute lower extremity deep venous thrombosis in symptomatic and asymptomatic patients: imaging implications.

Abstract

The ability of noninvasive imaging modalities to di· agnose lower extremity DVT depends, in part, on the anatomic location of the thrombus. To define the pattern of thrombus formation in symptomatic and asymptomatic high-risk patient populations, 172 con• secutive lower extremity venograms were submitted to blinded, retrospective interpretation. Acute DVT was present in 59 venograms (34 symptomatic and 25 asymptomatic patients).Among symptomatic patients with acute DVT, 26 of 34 (76%) patients had an above-knee thrombus and only eight of 34 (24%) patients had a thrombus isolated to the calf. In comparison, only three of 25 (12%) asymptomatic patients with DVT had an above-knee thrombus and 22 of 25 (88%) patients had a thrombus L ower extremity DVT is a common disorder that may have serious consequences in the form of a pulmonary embolism or lower extremity chronic venous insufficiency. The distribu-ABBREVIATIONS DVI', Deep venous thrombosis

Venous Thromboembolism in Trauma: A Local Manifestation of Systemic Hypercoagulability?

“…The sensitivity of VDUS for isolated calf vein thrombosis has been questioned but may be as high as 95% for technically adequate studies in symptomatic patients. 37 Although clearly lower in asymptomatic postoperative orthopedic patients, sensitivity may still be as high as 80% for technically adequate examinations 38,39 and is presumably even higher when serial examinations are performed. Although not proving the accuracy of calf vein ultrasonography, the actuarial incidence of ultrasound-documented DVT in this study was remarkably similar to that reported in venographic studies.…”

Ultrasound of limb veins

“…Most calf thrombi occur in the asymptomatic patient group and this accounts for 50±63 % of thrombi in the asymptomatic population [28,34], whereas in symptomatic patients these figures are less than 5 % [35,36]. It is advocated not only to scan the deep calf veins but also to include the superficial soleal and gastrocnemial veins as 40 % of the thrombi are located in the superficial veins [36].…”

Direct contrast-enhanced 3D MR venography

“…Whereas symptomatic patients tend to have more extensive DVT frequently involving the femoropopliteal venous segments, where thrombosis can be readily detected, asymptomatic patients often have smaller and non-occlusive thrombi frequently isolated to the calf veins [12]. Results of studies comparing duplex ultrasonography to conventional venography report sensitivity and specificity values ranging from 38 to 100 %, and 73 to 100 %, respectively [11,13,14,15,16,17,18,19,20,21].Currently in many institutions duplex ultrasonography has replaced conventional ascending venography for the evaluation of chronic venous insufficiency.…”