I appreciate the valuable comments by Dr Kahn. Isolated calf thrombosis of the soleal or gastrocnemial muscle veins has been known for over 30 years.1 A sonographic study retrospectively investigating thrombus distribution in clinically suspected DVT showed ICMVT in 37% of sonographically proven symptomatic calf thromboses.2 The results of our study on flight-associated thrombosis indicate that the incidence of (asymptomatic) ICMVT is about 100 times higher than the incidence of (symptomatic) DVT.3 This finding raises the obvious question of the clinical relevance of these small calf clots.
Schwarz T. Venous Thrombosis in Long-Haul Travelers—Reply. Arch Intern Med. 2004;164(15):1699-1700. doi:10.1001/archinte.164.15.1700