[Difficulties of functional exploration of the veins in the obese. Problems that may be posed in its interpretation].

Obesity modifies the tissular anatomy and the mechanical characteristics of the limb. Because of this, there are difficulties in the interpretation of results produced by techniques designed to explore the venous functioning of the limbs. Our work has two main objectives. First of all a retrospective study shows that venous plethysmography is comparably sensitive in the obese patient with regard to the diagnosis of phlebitis (90% in the obese patient; 95% in the non-obese). As regards specific detail, however, it is not as good in the case of the obese patient (88.7% against 97.5%). Another, prospective, study on the normal, that is non-varicose, subject (obese and non-obese), enables us to analyse parameters modified by obesity, certain false positives in venous distensibility.