Incidence of deep vein thrombosis from screening by venous ultrasonography in Japanese patients

The aim of the present study was to investigate the incidence of deep vein thrombosis (DVT) patients in a Japanese population by screening them with venous ultrasonography. This retrospective, single-center analysis examined 963 patients who underwent venous ultrasonography in 2015. The primary outcome was the incidence of DVT, and secondary outcomes were predictive factors of DVT in patient characteristics, treatment strategy for DVT patients, and proportion of post thrombotic syndrome (PTS). The overall incidence rate of DVT was 10.3% (100/963). The location of thrombus was the iliac vein in 3.6% (n = 35), the femoral vein in 4.4% (n = 43), and the calf vein in 8.2% (n = 79) of the patients. The main complaint or purpose of examination was perioperative screening in 37% of the patients, leg edema and/or limb swelling in 27% of the patients, and skin disease in 8% of the patients. In a multivariate analysis, the incidence of DVT was significantly higher in the hospitalization group and the "having symptoms" group. Fifty percent of DVTs received treatment, and almost all therapies were medical treatment with oral anticoagulants (OAC). Within a three-year follow-up period, the proportion of PTS was 27% with no significant difference between anticoagulation or non-anticoagulation patients; the risk of PTS was in concomitant varicose veins. In conclusion, of the patients, 10.3% were diagnosed with DVT, and only half received treatment with only anticoagulation.