Correlation of clinical features with the risk of lower limb deep vein thrombosis assessed by duplex ultrasound

BACKGROUND: Symptoms and clinical signs suggestive of deep vein thrombosis (DVT) are common but may have numerous possible causes. OBJECTIVES: 1) To identify the most frequent clinical symptoms and correlate them with duplex ultrasound scan (DS) findings; 2) to identify high-risk clinical conditions for DVT; and 3) to evaluate time since the onset of symptoms and DS examination. METHODS: A total of 528 patients with a clinical suspicion of DVT were evaluated by DS performed by experienced vascular ultrasonographists. RESULTS: DVT was present in 192 (36.4%) of the patients. The external iliac vein was involved in 53 patients (10.04%), the femoral veins in 110 (20.83%), the popliteal vein in 124 (23.48%), and veins below the knee were involved in 157 (29.73%) of the cases. Limb swelling was present in 359 cases (68%), and 303 (57.4%) complained of pain. Sixty nine patients received a DS due to suspected or proven pulmonary embolism (PE); 79 patients were in postoperative period. In the multivariate analysis, independent risk factors for DVT included age>65 years (OR=1.49; 95% confidence interval [95%CI] 1.01-2.18; p=0.042), edema (OR=2.83; 95%CI 1.72-4.65; p<0.001), pain (OR=1.99; 95%CI 1.3-3.05; p=0.002), cancer (OR=2.32; 95%CI 1.45-3.72; p<0.001), and PE (OR=2.62; 95%CI 1.29-5.32; p=0.008).Time since the onset of symptoms did not differ between the groups. CONCLUSIONS: In the present study, 36.4% of the patients referred to DS had DVT. Age > 65 years, presence of limb swelling, pain, cancer, and suspected or proven PE should be considered as major risk factors for DVT