Comparison of real-time B-mode ultrasonography and bilateral ascending phlebography for detection of postoperative deep vein thrombosis following elective hip surgery. The Venous Thrombosis Group.

A prospective study compared real-time B-mode ultrasound examination with bilateral ascending phlebography in the diagnosis of postoperative deep vein thrombosis in 60 patients undergoing elective total hip replacement. The overall sensitivity and specificity of the ultrasound method were 54 and 91%, respectively, and the positive and negative predictive values were 83 and 69%, respectively. The rather low overall sensitivity of the ultrasound method in this study was due to difficulty in detecting thrombi smaller than 1 cm wherever they were located in the deep veins, and in diagnosing thrombi in the calf, regardless of their size. We conclude that real-time B-mode ultrasonography is a technique that can easily be used routinely for detection of postoperative DVT in hip surgery, but its sensitivity for proximal thrombosis (63%) is too low for it to be used alone.