A profile of lower-limb deep-vein thrombosis: the hidden menace of below-knee DVT

AimsTo describe the anatomical site and laterality of deep-vein thrombosis (DVT) in symptomatic patients using contrast venography (CV), and to assess age, sex distribution, and accuracy of pre-test clinical suspicion of DVT.MethodsOne thousand, five hundred and seventy-two patients undergoing CV because of a clinical suspicion of DVT at a large teaching hospital from October 1995 to March 2003 were prospectively studied.ResultsThrombi were demonstrated in 511 (32.5%) of all CV studies. Isolated, below-knee thrombi were identified in 29.4% of positive studies. There was a left-sided predominance of DVT (ratio 1.24:1) that was most evident in the elderly and in more proximal veins.ConclusionAlmost a third of positive cases were shown to be isolated, below-knee thrombi. These are thrombi that are more difficult to detect by non-invasive means. A left-sided predominance of DVT is evident.