Epidemiologic Analysis of Proximal Deep Vein Thrombosis in Thai Patients: Malignancy, the Predominant Etiologic Factor

From January 1995 to December 2000, 1555 patients (585 males, 970 females, with a mean age of 52.3 years) with acute limb swelling underwent diagnostic duplex venous ultrasonagraphy at the Vascular Surgery Unit, Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. Of these 1555 patients, 514 (188 males, 326 females, with a mean age of 53 years) were diagnosed with deep vein thrombosis (DVT). DVT was found mainly in the lower extremities, occurring in 506 of these 514 cases (98.4%). The affected vein in the lower extremity was found more commonly in the left side (359 limbs) than in the right side (184 limbs) (p < 0.001). DVT also occurred in the upper extremities in 8 of the 514 cases (1.6%). In this study, out of 308 patients with DVT in their lower limbs, DVT was associated with malignancy in 123 cases (39.9%), with postoperation in 48 cases (15.6%), and with limb immobilization in 38 cases (12.3%). Malignancy-related DVT was found to be more extensive and virulent and was associated with high morbidity and mortality. Further study should be conducted to investigate the role of anticoagulant drugs for the prevention of DVT in cancer patients. Perhaps the spectrum of DVT as presented in this series is characteristic not only of the Thai population but also of the populations of other Asian countries.