The LONFLIT4-Concorde - Sigvaris Traveno Stockings in Long Flights (EcoTraS) Study

Abstract

The LONFLIT1/2 studies have established that in high-risk subjects after long (> 10 hours) flights the incidence of deep venous thrombosis (DVT) may be between 4% and 6%. The LONFLIT4 study was aimed at evaluating the control of edema and DVT prevention in low- medium-risk subjects. In this study prophylaxis of edema with specific travel stockings was evaluated in 2 separate studies involving flights lasting 7 hours and 10-12 hours. Part I. Sub jects at low-medium risk for DVT were contacted; 55 subjects were excluded for several nonmedical, travel-related problems or inconvenient evaluation time; the remaining 211 were randomized into 2 groups to evaluate prophylaxis with elastic stockings in 7-8-hour, long- haul flights. The control group had no prophylaxis; the treatment group used below-knee, Sigvaris Traveno elastic stockings (Ganzoni, Switzerland, producing 12-18 mm Hg of pressure at the ankle). Color duplex scanning was used to evaluate the possible presence of DVT; edema/swelling were evaluated with a composite score including the presence of edema (with an edema tester), variations in ankle circumference and leg volumetry, subjective swelling, and discomfort (scale ranging from 0 to 10). Results: Of the 103 included subjects in the stockings group and 108 in the control group (total 211), 195 subjects completed the study. Dropouts (16) were due to low compliance or traveling and connection problems. Age, sex distribution, and risk factors distributions were comparable in the 2 groups. Stockings Group: Of 97 subjects none had DVT or superficial thromboses. Control Group: Of 98 subjects none had thrombosis. The level of edema at inclusion was comparable in the 2 groups of subjects. After flights there was an average score of 6.4 (1.3) in the control group, while in the stockings group the score was on average 2.4 (SD 1), 2.6 times lower than in the control group (p < 0.05). In the control group 83% of the subjects had an evident increase in ankle circumference and volume that was visible at inspection and associated with discomfort. The control of edema with stockings was clear, considering both parametric data (circumference and volume) and