[Exploratory strategy in venous thromboembolic disease].
It is currently accepted that the clinical signs are not very reliable in the diagnosis of deep venous thromboses (DVT). For this reason, various methods, more objective, are used in daily practice. Anatomical methods permitting direct visualization of the thrombus: one is invasive: phebography, the other is non-invasive: ultrasonography, which is quite competitive with the previous one and presents the advantage of evaluating the surrounding structures and providing functional informations when associated with a Doppler test. Haemodynamic functional methods, less reliable, permitting an indirect evaluation of the venous return: the Doppler analyzes the blood velocity, qualitatively and subjectively, plethysmography, more objective, studies the variations of the blood volume, artificially created by venous obstruction. Isotopic methods, using radioactive materials incorporated in the coagulation factors resulting in the formation of a thrombus, such as iodine 125 labelled fibrinogen. Biological methods, reflecting the formation and dissolving of a thrombus: it consists in the plasma titration of D-Dimer, specific disintegration product of fibrin. The advantages, limitations and indications of each technique are discussed. Selection of the exploration method must take into consideration the prevalence of DVTs and the value of the tests according to various clinical situations: presence or not of thrombogenic circumstances (ambulatory patient, hospitalized patient), presence or not of clinical manifestations (high-risk asymptomatic patient, symptomatic patient). Haemodynamic and isotopic tests have been substituted for phlebography. The current tendency leans toward Ultrasonography-Doppler, a very reliable method in symptomatic patients, but its value still has not been properly determined under other circumstances.