Incidence and risk factors of post-thrombotic syndrome in patients with isolated calf vein thrombosis. Findings from the GARFIELD-VTE registry

In contrast with extensive information on the risk of post-thrombotic syndrome (PTS) in patients with proximal deep vein thrombosis (DVT) of the lower extremities [1], little is known for patients with isolated distal DVT (IDDVT), which is expected to account for approximately one third of all DVTs of the lower extremities [2]. The heterogeneity of available studies, the variability of initial and long-term treatment, the variable duration of follow-up, the different study modalities, and the lack of standardization of criteria used for PTS assessment virtually preclude a reliable quantification of PTS rate and severity, which have indeed varied greatly across available studies [2,3].