Passengers should reduce consumption of alcohol on flights

EDITOR—Geroulakos,1 like previous reviewers of the relation between air travel and venous thromboembolism,2 did not mention the theoretical and experimental evidence of thrombogenesis in venous valve pockets that colleagues and I have published.3 Modelled on one of the six possible permutations of Virchow's triad, our experiments produced experimental thrombi in venous valve pockets for the first time since Virchow described them in 1858.4 The specific triad model was (1) interrupted circulation in venous valve pockets causing (2) hypoxaemic metabolic endothelial injury and leading to (3) ectopic haemostatic plug formation (blood metamorphosis) in valve pockets.

Merely to move blood clotting from position 1 to position 3 in the triad sequence gives a new explanation for thrombogenesis. This suggests that thrombogenesis during long haul flights is attributable to individual passengers' behaviour—specifically, taking an excess of drugs …