IntroductionIt is essential to look for maximal efficiency in all diagnostic and therapeutic procedures, and especially in times of health budget cuts. The LEAN method tries to optimise all production procedures, and its application is proposed in the lower limb venous duplex ultrasound study. Materials and methodsPatients suffering from venous insufficiency (VI), external varicose veins, and without previous venous surgery or deep vein thrombosis were included and a duplex ultrasound evaluation was performed according to the recommendations for non-invasive vascular diagnosis. Deep venous system, shunt type, trajectory and drainage were evaluated. The minimum number of ultrasound evaluation points needed for a correct diagnosis was determined (LEAN points), and an efficient decision-making algorithm was developed. ResultsA descriptive, cross-sectional study was conducted on 984 lower limb venous ultrasound evaluations performed between 2007 and 2012. Almost all (96%) patients had a shunt and trajectory correctly evaluated by groin ultrasound evaluation (LEAN-1), and popliteal area ultrasound evaluation (LEAN-2). Only 3.6% of these patients showed a secondary shunt that was not located in LEAN points. Another 4.2% of patients did not show any shunt in LEAN-1 or LEAN-2, being due to thigh perforating veins (50%), leg perforating veins (30%), or Hunter perforating veins (20%). ConclusionsThe duplex ultrasound evaluation of LEAN-1 and LEAN-2 points allows us to reach a complete diagnosis for VI in 92.4% of patients, thus reducing evaluation time and costs. According to the proposed algorithm, only 4.2% of patients would need a complete venous ultrasound evaluation to reach the correct diagnosis.