Duplex scanning in the postoperative surveillance of patients undergoing total hip arthroplasty.
Color flow duplex imaging is a well-established method for the diagnosis of deep vein thrombosis in symptomatic patients; however, the sensitivity and specificity of duplex scanning compared with venography in high-risk asymptomatic patients are not known. Consecutive patients undergoing total hip arthroplasty who consented to have bilateral venography on days 8 to 12 were included in this prospective study. One hundred and fifty-one venograms were finally obtained in 78 patients. All duplex scanning was performed with the Ultramark 9 ATL (Advanced Technology Laboratories) by one investigator. In the beginning of the study, the first 44 legs, only the femoropopliteal segment was tested and the result was based on B-mode compression; the sensitivity for the duplex was 56% (5/9), and the specificity, 94% (33/35). In the next 107 legs, the addition of color to our criteria improved the sensitivity of the duplex scan from 55% to 93% (13/14) for the femoropopliteal segment and the specificity from 94% to 99% (92/93). For the calf segment, in the same 107 legs, using the color facility of the duplex, the sensitivity and specificity were 79% (15/19) and 97% (85/88), respectively. The color facility of new-generation machines makes duplex scanning reliable for the detection of proximal deep vein thrombosis, even in asymptomatic high-risk patients. For the detection of calf deep vein thrombosis, however, more experience is needed. A larger study is necessary to confirm these preliminary data.
Kalodiki
E
E
Irvine Laboratory for Cardiovascular Investigation and Research, St. Mary's Hospital, London, United Kingdom.
Nicolaides
A N
AN
al-Kutoubi
A
A
Cunningham
D A
DA
Crofton
M
M
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000517:prevention & control; D011184:Postoperative Period; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013927:Thrombosis / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex