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

Abstract

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 the control group (102 subjects; mean age, 42.1; SD 10.3; M:F, 56:46), six subjects (5.8%) had a DVT. There were no superficial thromboses. The difference in DVT incidence is significant (p<0.0025; six times greater in the control group). Intention-to-treat analysis counts 18 failures in the control group (12 lost to follow-up + six thromboses) of 112 subjects (15.8%) versus eight failures (7.3%) in the treatment group (p<0.05). The tolerability of the stockings was very good and there were no complaints or side effects. All events were asymptomatic. Considering these observations, Scholl Flight Socks are effective in reducing the incidence of DVT in high-risk subjects.

Keywords

Deep venous thrombosis Edema Flight-microangiopathy Noninvasive investigations Ultrasound Travel Airplanes Long-haul flights Prevention Elastic compression

References

1. Geroulakos G , Hossain J , Tran T . Economy-class syndrome presenting as phlegmasia caerulea dolens. Eur J Vasc Endovasc Surg 2000;20:102-102.

2. Perry K . Blood clot kills woman after flight. Guardian 2001;23-23.

3. Homans J . Thrombosis of the deep leg veins due to prolonged sitting. N Engl J Med 1954;250:148-148.

4. Symington IS , Stack BHR . Pulmonary thromboembolism after travel. Br J Chest 1977;17:138-138.

5. Simpson K . Shelter deaths from pulmonary embolism. Lancet 1940;11:744-744.

6. Ferrari E , Chevallier T , Chapelier A , et al. Travel as a risk factor for venous thromboembolic disease: A case control study. Chest 1999;115:440-440.

7. Cruickshank JM , Gorlin R , Jennett B . Air travel and thrombotic episodes: The economy class syndrome. Lancet 1988;2:497-497.

8. Kraaijenhagen R , Haverkamp D , Koopman MMW , et al. Travel and risk of venous thrombosis. Lancet 2000;356: 1492-1492.

9. Sarvesvaran R . Sudden natural deaths associated with commercial air travel. Med Sci Law 1986;26:35-35.

10.

10. Landgraf H , Vanselow B , Schulte-Huerman D , et al. Economy class syndrome: Rheology fluid balance and lower leg oedema during a simulated 12-hour long-distance flight. Aviat Space Environ Med 1994;65:930-930.

11.

11. AMA Commission on Emergency Services . Medical aspects of transportation aboard commercial aircraft. JAMA 1982;247:1007-1007.

12.

12. Gertler JP , Perry L , L'Italien G , et al. Ambient oxygen tension modulates endothelial fibrinolysis. J Vasc Surg 1993;18:939-939.

13.

13. Bendz B , Rostrup M , Sevre K , et al. Association between acute hypobaric hypoxia and activation of coagulation in human beings. Lancet 2000;356:1657-1657.

14.

14. Belcaro G , Geroulakos G , Nicolaides AN , et al. Maladie veineuse thrombo-embolique apres vol aerien. Les etudes LONFLIT. Angeiologie 2001;53:17-17.

15.

15. Belcaro G , Geroulakos G , Nicolaides AN , et al. Venous thromboembolism from air travel. The Lonflit Study. Angiology 2001;52:369-369.

16.

16. Cesarone MR , Belcaro G , Nicolaides AN , et al. Venous thromboembolism from air travel: The Lonflit3 study. Prevention with Aspirin vs low-molecular weight-heparin (LMWH) in high-risk subjects: A randomised trial. Angiology 2002;53:1-1.

17.

17. Belcaro G . Venous thrombosis and air-travel: Prevention with aspirin or low-molecular-weight-heparin. Circulation 2001; 104:II-528.

18.

18. Belcaro G , Geroulakos G , Nicolaides AN , et al. Prevention of deep venous thrombosis on long-haul flights. J Am Coll Cardiol 2002;39:212A-212A.

19.

19. Anonymous . Stockings, heparin found to eliminate “coach class” syndrome. American Heart Association Scientific Sessions 2001, Nov 14; 3; pg 8-8.

20.

20. Belcaro G , Nicolaides AN , Veller M . Venous Disorders: A Manual of Diagnosis and Treatment. Cambridge: Saunders, 1996.

21.

21. Belcaro G , Nicolaides AN . Noninvasive Investigations in Vascular Disease. London: Imperial College Press, 2001.

22.

22. Mendis S , Yach D , Alwan A . Air travel and venous thromboembolism. Bull WHO 2002;80:403-403.

23.

23. Cesarone MR, Meli E. Volare con Sicurezza. Jet-leg. Il problema dell'edema e della trombosi in voli di lunga durata. Turin: Ediz Minerva Medica, 2001.

24.

24. Belcaro G , Nicolaides AN , Stansby G . The Venous Clinic. London: Imperial College Press, 1999.

25.

25. Scurr JH , Machin SJ , Bayley S , et al. Frequency and prevention of symptomless deep-vein thrombosis in long-haul flights: A randomised trial. Lancet 2001;357:1485-1485.

26.

26. Belcaro G , Cesarone MR , Shah S , et al. Prevention of edema, flight microangiopathy and venous thrombosis in long flights with elastic stockings. A randomized trial: The LONFLIT 4 Concorde Edema-SSL Study. Angiology 2002;53:635-635.

27.

27. Cesarone MR , Belcaro G , Errichi BM , et al. The LONFLIT4-concorde deep venous thrombosis and edema study: prevention with travel stockings. Angiology 2003; 54:143-143.

28.

28. Cesarone MR , Belcaro G , Brandolini R , et al. The LONFLIT4—venoruton study: A randomized trial. Prophylaxis of flight-edema in venous patients. Angiology 2003; 54:137-137.

29.

29. Rosendaal FR , Buller HR , Kesteven P , Toff WD . Long haul flights and deep vein thrombosis: who is at risk? Br J Haematol 2003;120:367-367.

30.

30. Campbell C , Rayner CF . Guidelines on prevention of venous thromboembolism during long haul flights. Thorax 2003;58:91-91.

31.

31. Schwarz T , Langenberg K , Oettler W , et al. Deep vein and isolated calf muscle vein thrombosis following long-haul flights: pilot study. Blood Coagul Fibrinolysis 2002; 13:755-755.

32.

32. Schobersberger W , Hauer B , Sumann G , Gunga HC , Partsch H . Traveler's thrombosis: Incidence, etiology, prevention]. Wien Klin Wochenschr 2002;114 14-14.

33.

33. Schobersberger W , Schobersberger B , Mittermayr M , Fries D . Travel-induced thrombosis: an update]. Wien Med Wochenschr 2002;152:445-445.

34.

34. Teruya T , Arfvidsson B , Eklof B . Could prolonged air travel be casually associated with subclavian vein thrombosis. J Travel Med 2002;9:17-17.

35.

35. Arya R , Barnes JA , Hossain U , Patel RK , Cohen AT . Longhaul flights and deep vein thrombosis: a significant risk only when additional factors are also present. Br J Haematol 2002;116:653-653.

36.

36. Murphy JF . The folded deckchair position: The problem of long-haul flights. Ir Med J 2001;94:260-260.

37.

37. Lethagen S . The connection of increased risk of thrombosis and long-haul flights is not proved. Lakartidningen 2001;98:4063-4063.

38.

38. Collin J . Deep-vein thrombosis in long-haul flights. Lancet 2001;358:838-838.

39.

39. Reynolds M . Deep-vein thrombosis in long-haul flights. Lancet 2001;358:838-838.

40.

40. Anderson R . Deep-vein thrombosis in long-haul flights. Lancet 2001;358:837-837.

41.

41. Burnand KG , McGuinness CL , Smith A . Deep-vein thrombosis in long-haul flights. Lancet 2001;358:837-837.

42.

42. Bendz B , Sandset P . Deep-vein thrombosis in long-haul flights. Lancet 2001;358:837-837.

43.

43. Wyss R , Stossel U , Muff S . Air travel-a disease risk? Ther Umsch 2001;58:399-399.

44.

44. Teenan RP , McKay AJ . Peripheral arterial thrombosis related to commercial airline flights: Another manifestation of the economy class syndrome. Br J Clin Pract 1992;46: 165-165.

45.

45. Hosoi Y , Geroulakos G , Belcaro G , Sutton S . Characteristics of deep vein thrombosis associated with prolonged travel. Eur J Vasc Endovasc Surg 2002;24:235-235.

46.

46. Belcaro G , Cesarone MR , Nicolaides AN , Geroulakos G , Griffin M . Prevention of flight venous thrombosis in high risk subjects with stockings or one-dose enoxaparine. Circulation 2002;106:721-721.