Serial 2-point ultrasonography plus D-dimer vs whole-leg color-coded Doppler ultrasonography for diagnosing suspected symptomatic deep vein thrombosis: a randomized controlled trial.
BACKGROUND
Patients with suspected deep vein thrombosis (DVT) of the lower extremities are usually investigated with ultrasonography either by the proximal veins (2-point ultrasonography) or the entire deep vein system (whole-leg ultrasonography). The latter approach is thought to be better based on its ability to detect isolated calf vein thrombosis; however, it requires skilled operators and is mainly available only during working hours. No randomized comparisons are yet available evaluating the relative values of these 2 strategies.


OBJECTIVE
To assess if the 2 diagnostic strategies are equivalent for the management of symptomatic outpatients with suspected DVT of the lower extremities.


METHODS
A prospective, randomized, multicenter study of consecutive symptomatic outpatients (n = 2465) with a first episode of suspected DVT of the lower extremities who were randomized to undergo 2-point or whole-leg ultrasonography. Data were taken from ultrasound laboratories of 14 Italian universities or civic hospitals between January 1, 2003, and December 21, 2006. Patients with normal ultrasound findings were followed up for 3 months, with study completion on March 20, 2007.


METHODS
Objectively confirmed 3-month incidence of symptomatic venous thromboembolism in patients with an initially normal diagnostic workup.


RESULTS
Of 2465 eligible patients, 345 met 1 or more exclusion criteria and 22 refused to participate; therefore, 2098 patients were randomized to either 2-point (n = 1045) or whole-leg (n = 1053) ultrasonography. Symptomatic venous thromboembolism occurred in 7 of 801 patients (incidence, 0.9%; 95% confidence interval [CI], 0.3%-1.8%) in the 2-point strategy group and in 9 of 763 patients (incidence, 1.2%; 95% CI, 0.5%-2.2%) in the whole-leg strategy group. This met the established equivalence criterion (observed difference, 0.3%;95% CI, -1.4% to 0.8%).


CONCLUSIONS
The 2 diagnostic strategies are equivalent when used for the management of symptomatic outpatients with suspected DVT of the lower extremities.


BACKGROUND
clinicaltrials.gov Identifier: NCT00353093.
Bernardi
Enrico
E
Department of Emergency and Accident Medicine, Civic Hospital, Conegliano, Italy. enrico.bernardi@ulss7.it
Camporese
Giuseppe
G
Büller
Harry R
HR
Siragusa
Sergio
S
Imberti
Davide
D
Berchio
Arrigo
A
Ghirarduzzi
Angelo
A
Verlato
Fabio
F
Anastasio
Raffaela
R
Prati
Carolina
C
Piccioli
Andrea
A
Pesavento
Raffaele
R
Bova
Carlo
C
Maltempi
Patrizia
P
Zanatta
Nello
N
Cogo
Alberto
A
Cappelli
Roberto
R
Bucherini
Eugenio
E
Cuppini
Stefano
S
Noventa
Franco
F
Prandoni
Paolo
P
D000368:Aged; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D014680:Veins / Q000000981:diagnostic imaging; D020246:Venous Thrombosis / Q000097:blood / Q000000981:diagnostic imaging*
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D