Color-flow duplex scanning for the surveillance and diagnosis of acute deep venous thrombosis

Abstract

Compared with conventional duplex imaging, color-flow scanning facilitates the identification of veins (especially below the knee), decreases the need to assess Doppler flow patterns and venous compressibility, and allows veins to be surveyed longitudinally. These advantages translate into a less demanding and time-consuming examination. This study was designed to determine the accuracy of color-flow scanning for detecting acute deep venous thrombosis in patients in whom the diagnosis is clinically suspected and in asymptomatic patients at high risk for developing postoperative deep venous thrombosis. The diagnostic group included 77 limbs of 75 patients, and the surveillance group included 190 limbs of 99 patients undergoing total hip or knee replacement. All patients were prospectively examined with color-flow scanning and phlebography. In the diagnostic group, the incidence of thrombi in below-knee veins (47%) was approximately equal to that in above-knee veins (43%); but in the surveillance group, the incidence of thrombi in below-knee veins (41%) far exceeded that in veins above the-knee (3%). Nonocclusive clots and clots isolated to a single venous segment were more common in the surveillance group. In symptomatic patients, color-flow scanning was 100% sensitive and 98% specific above the knee and 94% sensitive and 75% specific below the knee. In the surveillance group, color-flow scanning was significantly (20 < 0.001) less sensitive (55%) for detecting thrombi, 93% of which were confined to the tibioperoneal veins. Negative predictive values were 100% and 88% for the diagnostic and surveillance limbs, respectively. Positive predictive values were 80% for the diagnostic limbs and 89°/o for the surveillance limbs. Color-flow scanning effectively excludes above-knee deep venous thrombosis in symptomatic patients and asymptomatic high-risk patients and predicts the presence of above-knee thrombi in patients in the diagnostic group with reasonable accuracy (97%). We conclude that color-flow scanning is as accurate as conventional duplex imaging and, because of its advantages, is the noninvasive method of choice for evaluating patients with suspected deep venous thrombosis. Its role in the surveillance of patients at high risk remains to be determined and awaits further clinical evaluation. (J VAsc SURG 1992;15:366-76.) Accurate diagnosis of lower extremity deep venous thrombosis (DVT) is critical to the care of patients with thromboembolic disease. It is estimated

Trends in vena caval interruption

“…32 Delivered, with mention of postpartum complication 673. 33 Antepartum condition or complication 673. 34 Postpartum condition or complication (95% CI, 1.069-1.083; P Ͻ .01).…”

Duplex Scanning in Post-Operative Surgical Patients

“…In this study the numbers were too small to draw any conclusions. Two studies have investigated the accu racy of colour-coded duplex in post-operative patients having elective hip surgery [16,17a;Kalodiki et al,unpubl. data] (table 7).…”

Variacoes anatomicas dos vasos tibiais: diagnostico diferencial de trombose venosa profunda antiga pela ecografia vascular

“…has a sensitivity of 95% to 100% and specificity of 98% for the diagnosis of DVT in the femoropopliteal segment; and sensitivity of 80% to 94% and specificity of 75% for the infrapatellar segment 11,12 . The explanation for the lower accuracy of CDUS in the infrapatellar segment may be associated with its greater limitations when examining these veins because of their smaller caliber, the attenuation of edema, and the deeper position of vessels.…”