Prevention of Venous Thrombosis with Elastic Stockings During Long-Haul Flights: The LONFLIT 5 JAP Study

Summary: The aim of this study was to evaluate deep venous thrombosis (DVT) prophylaxis with specific elastic stockings in longhaul flights (11-13 hours), in high-risk subjects. A group of 300 subjects was included; 76 were excluded for several problems including concomitant treatments; 224 were randomized into two groups (stockings vs. controls) to evaluate prophylaxis with below-knee stockings. An exercise program was used in both groups. Scholl (UK) Flight Socks (14-17 mmHg of pressure at the ankle) were used. DVT was diagnosed with ultrasound scanning. The femoral, popliteal, and tibial veins were scanned before and within 90 minutes after the flights. Of the 205 included subjects, 102 controls and 103 treated subjects completed the study. Drop-outs were due to flight connection problems. Age, gender, and risk distributions were comparable in the two groups. In the treatment group (103 subjects; mean age, 42; SD 9; M:F, 55:48), one limited, distal DVT was observed (0.97%). In Prolonged air travel has been associated with DVT and pulmonary embolism (1-6). Compression of veins (i.e., the popliteal vein) on the edge of the seat could be a contributing factor to venous stasis and DVT. Blood concentration, decreased fluid intake, and water loss in the dry atmosphere of airplane cabins, have been implicated (7-